diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..be66b92
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "dep/tomlc99"]
+	path = dep/tomlc99
+	url = https://github.com/cktan/tomlc99.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b304447..b5a44cb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,8 +4,6 @@ cmake_minimum_required(VERSION 3.15...3.25)
 # Header must be included this way: #include <module/header.h>
 #
 # ├─ res
-# ├─ dep
-# │  └─ klib
 # ├─ src
 # │  ├─ lex
 # │  │  └─ lexer.l
@@ -29,6 +27,8 @@ set(CMAKE_C_STANDARD_REQUIRED TRUE)
 set(GEMSTONE_TEST_DIR ${PROJECT_SOURCE_DIR}/tests)
 set(GEMSTONE_BINARY_DIR ${PROJECT_SOURCE_DIR}/bin)
 
+add_compile_definitions(GSC_VERSION="${PROJECT_VERSION}")
+
 include(CTest)
 
 if(BUILD_TESTING)
@@ -63,10 +63,8 @@ set(YACC_SOURCE_FILE ${PROJECT_SOURCE_DIR}/src/yacc/parser.y)
 set(YACC_GENERATED_SOURCE_FILE ${PROJECT_SOURCE_DIR}/src/yacc/parser.tab.c)
 
 add_custom_command(OUTPUT ${YACC_GENERATED_SOURCE_FILE}
-
         COMMAND bison
         ARGS -Wno-yacc -Wcounterexamples -d -o ${YACC_GENERATED_SOURCE_FILE} ${YACC_SOURCE_FILE}
-
         COMMENT "generate C source file for parser"
         VERBATIM)
 
@@ -76,7 +74,28 @@ add_custom_command(OUTPUT ${YACC_GENERATED_SOURCE_FILE}
 
 find_package(PkgConfig REQUIRED)
 pkg_search_module(GLIB REQUIRED IMPORTED_TARGET glib-2.0)
-    
+
+# ------------------------------------------------ #
+#  TOML-C99                                        #
+# ------------------------------------------------ #
+
+execute_process(COMMAND git submodule init -- dep/tomlc99)
+
+add_custom_command(OUTPUT ${PROJECT_SOURCE_DIR}/dep/tomlc99/toml.c
+        COMMAND git
+        ARGS submodule update --init --recursive --checkout
+        COMMENT "checkout dependency TOML-C99"
+        VERBATIM)
+
+add_library(tomlc99 ${PROJECT_SOURCE_DIR}/dep/tomlc99/toml.c)
+set_target_properties(tomlc99
+        PROPERTIES
+        OUTPUT_NAME "toml"
+        ARCHIVE_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/dep)
+
+include_directories(${PROJECT_SOURCE_DIR}/dep/tomlc99)
+
+
 # ------------------------------------------------ #
 #  Source                                          #
 # ------------------------------------------------ #
@@ -109,6 +128,8 @@ set_target_properties(release
 
 target_link_libraries(release PkgConfig::GLIB)
 
+target_link_libraries(release tomlc99)
+
 # FIXME: cannot compile with /O2 because of /RTC1 flag
 if (MSVC)
     set(RELEASE_FLAGS)
@@ -127,6 +148,9 @@ target_compile_options(release PUBLIC ${FLAGS} ${RELEASE_FLAGS})
 # add src directory as include path
 target_include_directories(release PUBLIC src)
 
+# disable assertions
+target_compile_definitions(release PUBLIC NDEBUG="1")
+
 # ------------------------------------------------ #
 #  Target DEBUG                                    #
 # ------------------------------------------------ #
@@ -143,6 +167,8 @@ set_target_properties(debug
 
 target_link_libraries(debug PkgConfig::GLIB)
 
+target_link_libraries(debug tomlc99)
+
 if (MSVC)
     set(DEBUG_FLAGS /DEBUG)
 else()
@@ -174,6 +200,8 @@ set_target_properties(check
 
 target_link_libraries(check PkgConfig::GLIB)
 
+target_link_libraries(check tomlc99)
+
 if (MSVC)
     set(CHECK_FLAGS /DEBUG /WX)
 else()
diff --git a/Dockerfile b/Dockerfile
index 68265d8..bb287f7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,5 +10,7 @@ COPY --chown=lorang CMakeLists.txt /home/lorang/
 COPY --chown=lorang run-check-test.sh /home/lorang/
 COPY --chown=lorang .env /home/lorang/
 COPY --chown=lorang run-docker-build.sh /home/lorang/
+COPY --chown=lorang dep /home/lorang/dep
+COPY --chown=lorang .git /home/lorang/.git
 
 RUN cmake .
diff --git a/dep/tomlc99 b/dep/tomlc99
new file mode 160000
index 0000000..5221b3d
--- /dev/null
+++ b/dep/tomlc99
@@ -0,0 +1 @@
+Subproject commit 5221b3d3d66c25a1dc6f0372b4f824f1202fe398
diff --git a/src/ast/ast.c b/src/ast/ast.c
index 892af1f..4e3ba6f 100644
--- a/src/ast/ast.c
+++ b/src/ast/ast.c
@@ -5,7 +5,7 @@
 #include <sys/log.h>
 #include <assert.h>
 
-struct AST_Node_t *AST_new_node(enum AST_SyntaxElement_t kind, const char* value) {
+struct AST_Node_t *AST_new_node(TokenLocation location, enum AST_SyntaxElement_t kind, const char* value) {
   DEBUG("creating new AST node: %d \"%s\"", kind, value);
   assert(kind < AST_ELEMENT_COUNT);
 
@@ -23,6 +23,7 @@ struct AST_Node_t *AST_new_node(enum AST_SyntaxElement_t kind, const char* value
   node->child_count = 0;
   node->kind = kind;
   node->value = value;
+  node->location = location;
 
   return node;
 }
@@ -83,6 +84,9 @@ void AST_init() {
   lookup_table[AST_Negate] = "-";
   lookup_table[AST_Parameter] = "parameter";
   lookup_table[AST_ParamDecl] = "parameter-declaration";
+  lookup_table[AST_AddressOf] = "address of";
+  lookup_table[AST_Dereference] = "deref";
+  lookup_table[AST_Reference] = "ref";
 }
 
 const char* AST_node_to_string(const struct AST_Node_t* node) {
@@ -114,6 +118,14 @@ const char* AST_node_to_string(const struct AST_Node_t* node) {
   return string;
 }
 
+static inline unsigned long int min(unsigned long int a, unsigned long int b) {
+    return a > b ? b : a;
+}
+
+static inline unsigned long int max(unsigned long int a, unsigned long int b) {
+    return a > b ? a : b;
+}
+
 void AST_push_node(struct AST_Node_t *owner, struct AST_Node_t *child) {
   DEBUG("Adding new node %p to %p", child, owner);
   assert(owner != NULL);
@@ -134,6 +146,12 @@ void AST_push_node(struct AST_Node_t *owner, struct AST_Node_t *child) {
     PANIC("failed to allocate children array of AST node");
   }
 
+  owner->location.col_end = max(owner->location.col_end, child->location.col_end);
+  owner->location.line_end = max(owner->location.line_end, child->location.line_end);
+
+  owner->location.col_start = min(owner->location.col_start, child->location.col_start);
+  owner->location.line_start = min(owner->location.line_start, child->location.line_start);
+
   assert(owner->children != NULL);
 
   owner->children[owner->child_count++] = child;
diff --git a/src/ast/ast.h b/src/ast/ast.h
index ff8297b..519f10a 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -3,6 +3,7 @@
 #define _AST_H_
 
 #include <stdio.h>
+#include <io/files.h>
 
 /**
  * @brief The type of a AST node
@@ -75,6 +76,9 @@ enum AST_SyntaxElement_t {
   AST_Parameter,
   AST_Qualifyier,
   AST_ParamDecl,
+  AST_AddressOf,
+  AST_Dereference,
+  AST_Reference,
   AST_ELEMENT_COUNT
 };
 
@@ -94,6 +98,8 @@ struct AST_Node_t {
   // optional value: integer literal, string literal, ...
   const char* value;
 
+  TokenLocation location;
+
   // number of child nodes ownd by this node
   // length of children array
   size_t child_count;
@@ -133,7 +139,7 @@ const char* AST_node_to_string(const struct AST_Node_t* node);
 [[maybe_unused]]
 [[nodiscard("pointer must be freed")]]
 [[gnu::returns_nonnull]]
-struct AST_Node_t *AST_new_node(enum AST_SyntaxElement_t kind, const char* value);
+struct AST_Node_t *AST_new_node(TokenLocation location, enum AST_SyntaxElement_t kind, const char* value);
 
 /**
  * @brief Deallocate this node and all of its children.
diff --git a/src/cfg/opt.c b/src/cfg/opt.c
new file mode 100644
index 0000000..6de694e
--- /dev/null
+++ b/src/cfg/opt.c
@@ -0,0 +1,419 @@
+//
+// Created by servostar on 5/31/24.
+//
+
+#include <cfg/opt.h>
+#include <string.h>
+#include <sys/log.h>
+#include <io/files.h>
+#include <assert.h>
+#include <toml.h>
+
+static GHashTable* args = NULL;
+
+static void clean(void) {
+    GHashTableIter iter;
+    gpointer key, value;
+    g_hash_table_iter_init(&iter, args);
+
+    while (g_hash_table_iter_next(&iter, &key, &value)) {
+        free(value);
+        free(key);
+    }
+
+    g_hash_table_destroy(args);
+}
+
+void parse_options(int argc, char* argv[]) {
+    args = g_hash_table_new(g_str_hash, g_str_equal);
+
+    atexit(clean);
+
+    for (int i = 0; i < argc; i++) {
+        Option* option = malloc(sizeof(Option));
+        option->is_opt = g_str_has_prefix(argv[i], "--");
+        option->string = strdup(argv[i] + (option->is_opt ? 2 : 0));
+        option->index = i;
+        option->value = NULL;
+
+        char* equals = strchr(option->string, '=');
+        if (equals != NULL) {
+            option->value = equals + 1;
+            *equals = 0;
+        }
+
+        g_hash_table_insert(args, (gpointer) option->string, (gpointer) option);
+    }
+}
+
+bool is_option_set(const char* option) {
+    assert(option != NULL);
+    assert(args != NULL);
+    return g_hash_table_contains(args, option);
+}
+
+const Option* get_option(const char* option) {
+    if (g_hash_table_contains(args, option)) {
+        return g_hash_table_lookup(args, option);
+    }
+
+    return NULL;
+}
+
+GArray* get_non_options_after(const char* command) {
+    const Option* command_option = get_option(command);
+
+    if (command_option == NULL) {
+        return NULL;
+    }
+
+    GArray* array = g_array_new(FALSE, FALSE, sizeof(const char*));
+
+    GHashTableIter iter;
+    gpointer key, value;
+    g_hash_table_iter_init(&iter, args);
+
+    while (g_hash_table_iter_next(&iter, &key, &value)) {
+        Option* option = (Option*) value;
+        if (!option->is_opt && command_option->index < option->index) {
+            g_array_append_val(array, option->string);
+        }
+    }
+
+    if (array->len == 0) {
+        g_array_free(array, FALSE);
+        return NULL;
+    }
+
+    return array;
+}
+
+TargetConfig* default_target_config() {
+    DEBUG("generating default target config...");
+
+    TargetConfig* config = malloc(sizeof(TargetConfig));
+
+    config->name = strdup("out");
+    config->print_ast = false;
+    config->print_asm = false;
+    config->print_ir = false;
+    config->mode = Application;
+    config->archive_directory = strdup("archive");
+    config->output_directory = strdup("bin");
+    config->optimization_level = 1;
+    config->root_module = NULL;
+
+    return config;
+}
+
+TargetConfig* default_target_config_from_args() {
+    DEBUG("generating default target from command line...");
+
+    TargetConfig* config = default_target_config();
+
+    if (is_option_set("print-ast")) {
+        config->print_ast = true;
+    }
+
+    if (is_option_set("print-asm")) {
+        config->print_asm = true;
+    }
+
+    if (is_option_set("print-ir")) {
+        config->print_ir = true;
+    }
+
+    if (is_option_set("mode")) {
+        const Option* opt = get_option("mode");
+
+        if (opt->value != NULL) {
+            if (strcmp(opt->value, "app") == 0) {
+                config->mode = Application;
+            } else if (strcmp(opt->value, "lib") == 0) {
+                config->mode = Library;
+            } else {
+                print_message(Warning, "Invalid compilation mode: %s", opt->value);
+            }
+        }
+    }
+
+    if (is_option_set("output")) {
+        const Option* opt = get_option("output");
+
+        if (opt->value != NULL) {
+            config->name = strdup(opt->value);
+        }
+    }
+
+    GArray* files = get_non_options_after("compile");
+
+    if (files == NULL) {
+        print_message(Error, "No input file provided.");
+    } else {
+
+        if (files->len > 1) {
+            print_message(Warning, "Got more than one file to compile, using first, ignoring others.");
+        }
+
+        config->root_module = strdup( ((char**) files->data) [0]);
+
+        g_array_free(files, TRUE);
+    }
+
+    return config;
+}
+
+void print_help(void) {
+    DEBUG("printing help dialog...");
+
+    const char *lines[] = {
+        "Gemstone Compiler (c) GPL-2.0",
+        "Build a project target: gsc build [target]|all",
+        "Compile non-project file: gsc compile <target-options> [file]",
+        "Output information: gsc <option>",
+        "Target options:",
+        "    --print-ast      print resulting abstract syntax tree to a file",
+        "    --print-asm      print resulting assembly language to a file",
+        "    --print-ir       print resulting LLVM-IR to a file",
+        "    --mode=[app|lib] set the compilation mode to either application or library",
+        "    --output=name    name of output files without extension",
+        "Options:",
+        "    --verbose        print logs with level information or higher",
+        "    --debug          print debug logs (if not disabled at compile time)",
+        "    --version        print the version",
+        "    --help           print this hel dialog",
+    };
+
+    for (unsigned int i = 0; i < sizeof(lines) / sizeof(const char *); i++) {
+        printf("%s\n", lines[i]);
+    }
+}
+
+static void get_bool(bool* boolean, const toml_table_t *table, const char* name) {
+    DEBUG("retrieving boolean %s", name);
+
+    const toml_datum_t datum = toml_bool_in(table, name);
+
+    if (datum.ok) {
+        *boolean = datum.u.b;
+        DEBUG("boolean has value: %d", datum.u.b);
+    }
+}
+
+static void get_str(char** string, const toml_table_t *table, const char* name) {
+    DEBUG("retrieving string %s", name);
+
+    const toml_datum_t datum = toml_string_in(table, name);
+
+    if (datum.ok) {
+        *string = datum.u.s;
+        DEBUG("string has value: %s", datum.u.s);
+    }
+}
+
+static void get_int(int* integer, const toml_table_t *table, const char* name) {
+    DEBUG("retrieving integer %s", name);
+
+    const toml_datum_t datum = toml_int_in(table, name);
+
+    if (datum.ok) {
+        *integer = (int) datum.u.i;
+        DEBUG("integer has value: %ld", datum.u.i);
+    }
+}
+
+static int parse_project_table(ProjectConfig *config, const toml_table_t *project_table) {
+    DEBUG("parsing project table...");
+
+    // project name
+    get_str(&config->name, project_table, "version");
+    if (config->name == NULL) {
+        printf("Invalid project configuration: project must have a name\n\n");
+        return PROJECT_SEMANTIC_ERR;
+    }
+
+    // project version
+    get_str(&config->name, project_table, "name");
+
+    // author names
+    toml_array_t *authors = toml_array_in(project_table, "authors");
+    if (authors) {
+        config->authors = g_array_new(FALSE, FALSE, sizeof(char *));
+
+        for (int i = 0;; i++) {
+            toml_datum_t author = toml_string_at(authors, i);
+            if (!author.ok)
+                break;
+
+            g_array_append_val(config->authors, author.u.s);
+        }
+    }
+
+    // project description
+    get_str(&config->desc, project_table, "description");
+    // project license
+    get_str(&config->license, project_table, "license");
+
+    return PROJECT_OK;
+}
+
+static int get_mode_from_str(TargetCompilationMode* mode, const char* name) {
+    if (mode == NULL) {
+        return PROJECT_SEMANTIC_ERR;
+    }
+
+    if (strcmp(name, "application") == 0) {
+        *mode = Application;
+        return PROJECT_OK;
+    } else if (strcmp(name, "library") == 0) {
+        *mode = Library;
+        return PROJECT_OK;
+    }
+    printf("Invalid project configuration, mode is invalid: %s\n\n", name);
+    return PROJECT_SEMANTIC_ERR;
+}
+
+static int parse_target(const ProjectConfig *config, const toml_table_t *target_table, const char* name) {
+    DEBUG("parsing target table...");
+
+    TargetConfig* target_config = default_target_config();
+
+    target_config->name = (char*) name;
+
+    get_bool(&target_config->print_ast, target_table, "print_ast");
+    get_bool(&target_config->print_asm, target_table, "print_asm");
+    get_bool(&target_config->print_ir, target_table, "print_ir");
+
+    get_str(&target_config->root_module, target_table, "root");
+    get_str(&target_config->output_directory, target_table, "output");
+    get_str(&target_config->archive_directory, target_table, "archive");
+
+    get_int(&target_config->optimization_level, target_table, "opt");
+
+    char* mode = NULL;
+    get_str(&mode, target_table, "mode");
+    int err = get_mode_from_str(&target_config->mode, mode);
+    if (err != PROJECT_OK) {
+        return err;
+    }
+
+    g_hash_table_insert(config->targets, target_config->name, target_config);
+
+    return PROJECT_OK;
+}
+
+static int parse_targets(ProjectConfig *config, const toml_table_t *root) {
+    DEBUG("parsing targets of project \"%s\"", config->name);
+
+    toml_table_t *targets = toml_table_in(root, "target");
+    if (targets == NULL) {
+        print_message(Warning, "Project has no targets");
+        return PROJECT_SEMANTIC_ERR;
+    }
+
+    config->targets = g_hash_table_new(g_str_hash, g_str_equal);
+
+    for (int i = 0; i < MAX_TARGETS_PER_PROJECT; i++) {
+        const char *key = toml_key_in(targets, i);
+
+        if (key == NULL)
+            break;
+
+        toml_table_t *target = toml_table_in(targets, key);
+        parse_target(config, target, key);
+    }
+
+    return PROJECT_OK;
+}
+
+int load_project_config(ProjectConfig *config) {
+    DEBUG("loading project config...");
+
+    FILE *config_file = fopen(PROJECT_CONFIG_FILE, "r");
+    if (config_file == NULL) {
+        print_message(Error, "Cannot open file %s: %s", PROJECT_CONFIG_FILE, strerror(errno));
+        INFO("project file not found");
+        return PROJECT_TOML_ERR;
+    }
+
+    char err_buf[TOML_ERROR_MSG_BUF];
+
+    toml_table_t *conf = toml_parse_file(config_file, err_buf, sizeof(err_buf));
+    fclose(config_file);
+
+    if (conf == NULL) {
+        print_message(Error, "Invalid project configuration: %s", err_buf);
+        return PROJECT_SEMANTIC_ERR;
+    }
+
+    toml_table_t *project = toml_table_in(conf, "project");
+    if (project == NULL) {
+        print_message(Error, "Invalid project configuration: missing project table.");
+    }
+
+    if (parse_project_table(config, project) == PROJECT_OK) {
+        return parse_targets(config, conf);
+    }
+
+    toml_free(conf);
+    return PROJECT_SEMANTIC_ERR;
+}
+
+void delete_target_config(TargetConfig* config) {
+    if (config->root_module != NULL) {
+        free(config->root_module);
+    }
+    if (config->archive_directory != NULL) {
+        free(config->archive_directory);
+    }
+    if (config->name != NULL) {
+        free(config->name);
+    }
+    if (config->output_directory != NULL) {
+        free(config->output_directory);
+    }
+    free(config);
+}
+
+void delete_project_config(ProjectConfig* config) {
+    if (config->name != NULL) {
+        free(config->name);
+    }
+    if (config->authors != NULL) {
+        g_array_free(config->authors, TRUE);
+    }
+    if (config->desc != NULL) {
+        free(config->desc);
+    }
+    if (config->license != NULL) {
+        free(config->license);
+    }
+    if (config->targets != NULL) {
+        GHashTableIter iter;
+
+        g_hash_table_iter_init(&iter, config->targets);
+
+        char* key;
+        TargetConfig* val;
+        while (g_hash_table_iter_next(&iter, (gpointer) &key, (gpointer) &val)) {
+            delete_target_config(val);
+        }
+
+        g_hash_table_destroy(config->targets);
+    }
+
+    free(config);
+}
+
+ProjectConfig* default_project_config() {
+    ProjectConfig* config = malloc(sizeof(ProjectConfig));
+
+    config->authors = NULL;
+    config->name = NULL;
+    config->targets = NULL;
+    config->license = NULL;
+    config->version = NULL;
+    config->desc = NULL;
+
+    return config;
+}
diff --git a/src/cfg/opt.h b/src/cfg/opt.h
new file mode 100644
index 0000000..eca919f
--- /dev/null
+++ b/src/cfg/opt.h
@@ -0,0 +1,168 @@
+//
+// Created by servostar on 5/31/24.
+//
+
+#ifndef GEMSTONE_OPT_H
+#define GEMSTONE_OPT_H
+
+#include <glib.h>
+
+#define MAX_TARGETS_PER_PROJECT 100
+#define PROJECT_CONFIG_FILE "build.toml"
+
+#define PROJECT_OK 0
+#define PROJECT_TOML_ERR 1
+#define PROJECT_SEMANTIC_ERR 2
+
+#define TOML_ERROR_MSG_BUF 256
+
+typedef enum TargetCompilationMode_t {
+    // output an executable binary
+    Application,
+    // output a binary object file
+    Library
+} TargetCompilationMode;
+
+/**
+ * @brief A target defines a source file which is to be compiled into a specific
+ *        format. Additionally properties such as output folders can be set.
+ *        Intermediate representations can be printed as well.
+ */
+typedef struct TargetConfig_t {
+    char* name;
+    bool print_ast;
+    bool print_asm;
+    bool print_ir;
+    // root module file which imports all submodules
+    // if this is NULL use the first commandline argument as root module
+    char* root_module;
+    // output directory for binaries
+    char* output_directory;
+    // output directory for intermediate representations (LLVM-IR, Assembly, ...)
+    char* archive_directory;
+    // mode of compilation
+    TargetCompilationMode mode;
+    // number between 1 and 3
+    int optimization_level;
+} TargetConfig;
+
+/**
+ * @brief A project is a collection of targets. Each target can point to
+ *        very different sources. The project binds these targets together
+ *        and specifies metadata about the authors and others.
+ */
+typedef struct ProjectConfig_t {
+    // name of the project
+    char* name;
+    // description
+    char* desc;
+    // version
+    char* version;
+    // license
+    char* license;
+    // list of authors
+    GArray* authors;
+    GHashTable* targets;
+} ProjectConfig;
+
+/**
+ * @brief Represents a command line option.
+ */
+typedef struct Option_t {
+    // index in which the option appeared in the argument array
+    int index;
+    // identifier of the option
+    const char* string;
+    // option if format is equals to --option=value
+    const char* value;
+    // whether or not this option has a value
+    bool is_opt;
+} Option;
+
+/**
+ * @brief Create the default configuration for targets.
+ * @return A pointer to a new target configuration.
+ */
+[[nodiscard("must be freed")]]
+TargetConfig* default_target_config();
+
+/**
+ * @brief Create the default configuration for a project.
+ *        Contains no targets.
+ * @return A pointer to a new project configuration.
+ */
+[[nodiscard("must be freed")]]
+ProjectConfig* default_project_config();
+
+/**
+ * @brief Create a new default target configuration an write command line
+ *        option onto the default configuration.
+ * @return A default config with user specified values.
+ */
+[[nodiscard("must be freed")]]
+TargetConfig* default_target_config_from_args();
+
+/**
+ * @brief Load a project configuration from a TOML file with the name
+ *        PROJECT_CONFIG_FILE.
+ * @param config Configuration to fill values from file into.
+ * @return
+ */
+[[gnu::nonnull(1)]]
+int load_project_config(ProjectConfig *config);
+
+/**
+ * @brief Print a help dialog to stdout.
+ */
+void print_help(void);
+
+/**
+ * @brief Delete a project config by deallocation.
+ * @param config The config to free.
+ */
+[[gnu::nonnull(1)]]
+void delete_project_config(ProjectConfig* config);
+
+/**
+ * @brief Delete a target configuration by deallocation.
+ */
+[[gnu::nonnull(1)]]
+void delete_target_config(TargetConfig*);
+
+/**
+ * @brief Parse the given command line arguments so that calls to
+ *        is_option_set() and get_option() can be made safely.
+ * @param argc Number of arguments
+ * @param argv Array of arguments
+ */
+void parse_options(int argc, char* argv[]);
+
+/**
+ * @brief Tests whether an option was set as argument.
+ * @attention Requires a previous call to parse_options()
+ * @param option Name of option to check for.
+ * @return 1 if the options was set, 0 otherwise
+ */
+[[gnu::nonnull(1)]]
+bool is_option_set(const char* option);
+
+/**
+ * @brief Returns the options information if present
+ * @attention Requires a previous call to parse_options()
+ * @param option
+ * @return A valid option struct or NULL if not found.
+ */
+[[gnu::nonnull(1)]]
+const Option* get_option(const char* option);
+
+/**
+ * @brief Put a copy of all options whos index is greather than the index
+ *        of the option specified by command.
+ * @param command
+ * @return an array of options that followed command.
+ */
+[[gnu::nonnull(1)]]
+[[nodiscard("must be freed")]]
+GArray* get_non_options_after(const char* command);
+
+#endif //GEMSTONE_OPT_H
diff --git a/src/compiler.c b/src/compiler.c
new file mode 100644
index 0000000..709592e
--- /dev/null
+++ b/src/compiler.c
@@ -0,0 +1,248 @@
+//
+// Created by servostar on 6/2/24.
+//
+
+#include <compiler.h>
+#include <ast/ast.h>
+#include <stdlib.h>
+#include <sys/log.h>
+#include <yacc/parser.tab.h>
+#include <lex/util.h>
+#include <io/files.h>
+#include <assert.h>
+#include <cfg/opt.h>
+
+extern void yyrestart(FILE *);
+
+// Module AST node used by the parser for AST construction.
+[[maybe_unused]]
+AST_NODE_PTR root;
+// Current file which gets compiled the parser.
+// NOTE: due to global state no concurrent compilation is possible
+//       on parser level.
+[[maybe_unused]]
+ModuleFile *current_file;
+
+/**
+ * @brief Compile the specified file into AST
+ * @param ast Initialized AST module node to build program rules
+ * @param file The file to be processed
+ * @return EXIT_SUCCESS in case the parsing was success full anything lese if not
+ */
+[[nodiscard("AST may be in invalid state")]]
+[[gnu::nonnull(1), gnu::nonnull(1)]]
+static int compile_file_to_ast(AST_NODE_PTR ast, ModuleFile *file) {
+    assert(file->path != NULL);
+    assert(ast != NULL);
+
+    file->handle = fopen(file->path, "r");
+
+    if (file->handle == NULL) {
+        INFO("unable to open file: %s", file->path);
+        print_message(Error, "Cannot open file %s: %s", file->path, strerror(errno));
+        return EXIT_FAILURE;
+    }
+
+    DEBUG("parsing file: %s", file->path);
+    // setup global state
+    root = ast;
+    current_file = file;
+    yyin = file->handle;
+    yyrestart(yyin);
+    lex_reset();
+
+    yyparse();
+
+    // clean up global state
+    // current_file = NULL;
+    root = NULL;
+    yyin = NULL;
+
+    return EXIT_SUCCESS;
+}
+
+/**
+ * @brief Setup the environment of the target.
+ * @param target
+ * @return EXIT_SUCCESS if successful EXIT_FAILURE otherwise
+ */
+static int setup_target_environment(const TargetConfig *target) {
+    DEBUG("setting up environment for target: %s", target->name);
+
+    assert(target->output_directory != NULL);
+    assert(target->archive_directory != NULL);
+
+    int result = create_directory(target->archive_directory);
+    if (result != 0 && errno != EEXIST) {
+        const char *message = get_last_error();
+        assert(message != NULL);
+
+        print_message(Error, "Unable to create directory: %s: %s", target->archive_directory, message);
+        free((void *) message);
+        return EXIT_FAILURE;
+    }
+
+    result = create_directory(target->output_directory);
+    if (result != 0 && errno != EEXIST) {
+        const char *message = get_last_error();
+        assert(message != NULL);
+
+        print_message(Error, "Unable to create directory: %s: %s", target->output_directory, message);
+        free((void *) message);
+        return EXIT_FAILURE;
+    }
+
+    return EXIT_SUCCESS;
+}
+
+/**
+ * @brief Print the supplied AST of the specified target to a graphviz ".gv" file
+ * @param ast
+ * @param target
+ */
+static void print_ast_to_file(const AST_NODE_PTR ast, const TargetConfig *target) {
+    assert(ast != NULL);
+    assert(target != NULL);
+
+    if (!target->print_ast)
+        return;
+
+    // create file path to write graphviz to
+    const char *path = make_file_path(target->name, ".gv", 1, target->archive_directory);
+
+    FILE *output = fopen((const char *) path, "w");
+    if (output == NULL) {
+        const char *message = get_last_error();
+        print_message(Error, "Unable to open file for syntax tree at: %s: %s", path, message);
+        free((void *) message);
+    } else {
+
+        AST_fprint_graphviz(output, ast);
+
+        fclose(output);
+    }
+
+    free((void *) path);
+}
+
+/**
+ * @brief Build the given target
+ * @param unit
+ * @param target
+ */
+static void build_target(ModuleFileStack *unit, const TargetConfig *target) {
+    print_message(Info, "Building target: %s", target->name);
+
+    AST_NODE_PTR ast = AST_new_node(empty_location(), AST_Module, NULL);
+    ModuleFile *file = push_file(unit, target->root_module);
+
+    if (compile_file_to_ast(ast, file) == EXIT_SUCCESS) {
+        if (setup_target_environment(target) == 0) {
+
+            print_ast_to_file(ast, target);
+
+            // TODO: parse AST to semantic values
+            // TODO: backend codegen
+        }
+    }
+
+    AST_delete_node(ast);
+
+    print_file_statistics(file);
+}
+
+/**
+ * @brief Compile a single file.
+ *        Creates a single target by the given command line arguments.
+ * @param unit
+ */
+static void compile_file(ModuleFileStack *unit) {
+    INFO("compiling basic files...");
+
+    TargetConfig *target = default_target_config_from_args();
+
+    if (target->root_module == NULL) {
+        print_message(Error, "No input file specified.");
+        delete_target_config(target);
+        return;
+    }
+
+    build_target(unit, target);
+
+    delete_target_config(target);
+}
+
+/**
+ * @brief Build all project targets specified by the command line arguments.
+ * @param unit
+ * @param config
+ */
+static void build_project_targets(ModuleFileStack *unit, const ProjectConfig *config) {
+    if (is_option_set("all")) {
+        // build all targets in the project
+        GHashTableIter iter;
+
+        g_hash_table_iter_init(&iter, config->targets);
+
+        char *key;
+        TargetConfig *val;
+        while (g_hash_table_iter_next(&iter, (gpointer) &key, (gpointer) &val)) {
+            build_target(unit, val);
+        }
+        return;
+    }
+
+    // build all targets given in the arguments
+    GArray* targets = get_non_options_after("build");
+
+    if (targets != NULL) {
+        for (guint i = 0; i < targets->len; i++) {
+            const char *target_name = (((Option*) targets->data) + i)->string;
+
+            if (g_hash_table_contains(config->targets, target_name)) {
+                build_target(unit, g_hash_table_lookup(config->targets, target_name));
+            } else {
+                print_message(Error, "Unknown target: %s", target_name);
+            }
+        }
+
+        g_array_free(targets, FALSE);
+    } else {
+        print_message(Error, "No targets specified.");
+    }
+}
+
+/**
+ * @brief Build targets from project. Configuration is provided by command line arguments.
+ * @param unit File storage
+ */
+static void build_project(ModuleFileStack *unit) {
+    ProjectConfig *config = default_project_config();
+    int err = load_project_config(config);
+
+    if (err == PROJECT_OK) {
+        build_project_targets(unit, config);
+    }
+
+    delete_project_config(config);
+}
+
+void run_compiler() {
+    ModuleFileStack files = new_file_stack();
+
+    if (is_option_set("build")) {
+        build_project(&files);
+    } else if (is_option_set("compile")) {
+        compile_file(&files);
+    } else {
+        print_message(Error, "Invalid mode of operation. Rerun with --help.");
+    }
+
+    if (files.files == NULL) {
+        print_message(Error, "No input files, nothing to do.");
+        exit(1);
+    }
+
+    print_unit_statistics(&files);
+    delete_files(&files);
+}
diff --git a/src/compiler.h b/src/compiler.h
new file mode 100644
index 0000000..a82a38f
--- /dev/null
+++ b/src/compiler.h
@@ -0,0 +1,13 @@
+//
+// Created by servostar on 6/2/24.
+//
+
+#ifndef GEMSTONE_COMPILER_H
+#define GEMSTONE_COMPILER_H
+
+/**
+ * @brief Run the gemstone compiler with the provided command arguments.
+ */
+void run_compiler();
+
+#endif //GEMSTONE_COMPILER_H
diff --git a/src/io/files.c b/src/io/files.c
new file mode 100644
index 0000000..5f3ad02
--- /dev/null
+++ b/src/io/files.c
@@ -0,0 +1,356 @@
+//
+// Created by servostar on 5/30/24.
+//
+
+#include <io/files.h>
+#include <sys/log.h>
+#include <assert.h>
+#include <sys/col.h>
+
+#ifdef __unix__
+
+#include <sys/stat.h>
+
+#define MAX_PATH_BYTES PATH_MAX
+
+#elif defined(_WIN32) || defined(WIN32)
+
+#include <Windows.h>
+
+#define MAX_PATH_BYTES _MAX_PATH
+
+#endif
+
+ModuleFileStack new_file_stack() {
+    ModuleFileStack stack;
+    stack.files = NULL;
+
+    return stack;
+}
+
+ModuleFile *push_file(ModuleFileStack *stack, const char *path) {
+    assert(stack != NULL);
+
+    // lazy init of heap stack
+    if (stack->files == NULL) {
+        stack->files = g_array_new(FALSE, FALSE, sizeof(ModuleFile));
+    }
+
+    ModuleFile new_file = {
+            .path = path,
+            .handle = NULL
+    };
+
+    g_array_append_val(stack->files, new_file);
+
+    return ((ModuleFile *) stack->files->data) + stack->files->len - 1;
+}
+
+void delete_files(ModuleFileStack *stack) {
+    for (size_t i = 0; i < stack->files->len; i++) {
+        const ModuleFile *file = (ModuleFile *) stack->files->data + i;
+
+        if (file->handle != NULL) {
+            DEBUG("closing file: %s", file->path);
+            fclose(file->handle);
+        }
+
+    }
+
+    g_array_free(stack->files, TRUE);
+    DEBUG("deleted module file stack");
+}
+
+// Number of bytes to read at once whilest
+// seeking the current line in print_diagnostic()
+#define SEEK_BUF_BYTES 256
+
+static inline unsigned long int min(unsigned long int a, unsigned long int b) {
+    return a > b ? b : a;
+}
+
+// behaves like fgets except that it has defined behavior when n == 1
+static void custom_fgets(char *buffer, size_t n, FILE *stream) {
+    if (n == 1) {
+        buffer[0] = (char) fgetc(stream);
+        buffer[1] = 0;
+    } else {
+        fgets(buffer, (int) n, stream);
+    }
+}
+
+void print_diagnostic(ModuleFile *file, TokenLocation *location, Message kind, const char *message) {
+    assert(file->handle != NULL);
+    assert(location != NULL);
+    assert(message != NULL);
+
+    // reset to start
+    rewind(file->handle);
+
+    char *buffer = alloca(SEEK_BUF_BYTES);
+    unsigned long int line_count = 1;
+
+    // seek to first line
+    while (line_count < location->line_start && fgets(buffer, SEEK_BUF_BYTES, file->handle) != NULL) {
+        line_count += strchr(buffer, '\n') != NULL;
+    }
+
+    const char *accent_color = RESET;
+    const char *kind_text = "unknown";
+    switch (kind) {
+        case Info:
+            kind_text = "info";
+            accent_color = CYAN;
+            file->statistics.info_count++;
+            break;
+        case Warning:
+            kind_text = "warning";
+            accent_color = YELLOW;
+            file->statistics.warning_count++;
+            break;
+        case Error:
+            kind_text = "error";
+            accent_color = RED;
+            file->statistics.error_count++;
+            break;
+    }
+
+    const char *absolute_path = get_absolute_path(file->path);
+
+    printf("%s%s:%ld:%s %s%s:%s %s\n", BOLD, absolute_path, location->line_start, RESET, accent_color, kind_text, RESET,
+           message);
+
+    free((void *) absolute_path);
+
+    const size_t lines = location->line_end - location->line_start + 1;
+
+    for (size_t l = 0; l < lines; l++) {
+        printf(" %4ld | ", location->line_start + l);
+
+        size_t chars = 0;
+
+        // print line before token group start
+        size_t limit = min(location->col_start, SEEK_BUF_BYTES);
+        while (limit > 1) {
+            custom_fgets(buffer, (int) limit, file->handle);
+            chars += printf("%s", buffer);
+            limit = min(location->col_start - chars, SEEK_BUF_BYTES);
+
+            if (strchr(buffer, '\n') != NULL) {
+                goto cont;
+            }
+        }
+
+        printf("%s", accent_color);
+
+        chars = 0;
+        limit = min(location->col_end - location->col_start + 1, SEEK_BUF_BYTES);
+        while (limit > 0) {
+            custom_fgets(buffer, (int) limit, file->handle);
+            chars += printf("%s", buffer);
+            limit = min(location->col_end - location->col_start + 1 - chars, SEEK_BUF_BYTES);
+
+            if (strchr(buffer, '\n') != NULL) {
+                goto cont;
+            }
+        }
+
+        printf("%s", RESET);
+
+        // print rest of the line
+        do {
+            custom_fgets(buffer, SEEK_BUF_BYTES, file->handle);
+            printf("%s", buffer);
+        } while (strchr(buffer, '\n') == NULL);
+
+        cont:
+        printf("%s", RESET);
+    }
+
+    printf("      | ");
+    for (size_t i = 1; i < location->col_start; i++) {
+        printf(" ");
+    }
+
+    printf("%s", accent_color);
+    printf("^");
+    for (size_t i = 0; i < location->col_end - location->col_start; i++) {
+        printf("~");
+    }
+
+    printf("%s\n\n", RESET);
+}
+
+TokenLocation new_location(unsigned long int line_start, unsigned long int col_start, unsigned long int line_end,
+                           unsigned long int col_end) {
+    TokenLocation location;
+
+    location.line_start = line_start;
+    location.line_end = line_end;
+    location.col_start = col_start;
+    location.col_end = col_end;
+
+    return location;
+}
+
+TokenLocation empty_location(void) {
+    TokenLocation location;
+
+    location.line_start = 0;
+    location.line_end = 0;
+    location.col_start = 0;
+    location.col_end = 0;
+
+    return location;
+}
+
+void print_file_statistics(ModuleFile *file) {
+    if (file->statistics.info_count + file->statistics.warning_count + file->statistics.error_count < 1) {
+        return;
+    }
+
+    printf("File %s generated ", file->path);
+
+    if (file->statistics.info_count > 0) {
+        printf("%ld notice(s) ", file->statistics.info_count);
+    }
+
+    if (file->statistics.warning_count > 0) {
+        printf("%ld warning(s) ", file->statistics.warning_count);
+    }
+
+    if (file->statistics.error_count > 0) {
+        printf("%ld error(s) ", file->statistics.error_count);
+    }
+
+    printf("\n\n");
+}
+
+void print_unit_statistics(ModuleFileStack *file_stack) {
+    FileDiagnosticStatistics stats;
+    stats.info_count = 0;
+    stats.warning_count = 0;
+    stats.error_count = 0;
+
+    for (size_t i = 0; i < file_stack->files->len; i++) {
+        ModuleFile *file = (ModuleFile *) file_stack->files->data;
+
+        stats.info_count += file->statistics.warning_count;
+        stats.warning_count += file->statistics.warning_count;
+        stats.error_count += file->statistics.error_count;
+    }
+
+    if (stats.info_count + stats.warning_count + stats.error_count < 1) {
+        return;
+    }
+
+    printf("%d file(s) generated ", file_stack->files->len);
+
+    if (stats.info_count > 0) {
+        printf("%ld notice(s) ", stats.info_count);
+    }
+
+    if (stats.warning_count > 0) {
+        printf("%ld warning(s) ", stats.warning_count);
+    }
+
+    if (stats.error_count > 0) {
+        printf("%ld error(s) ", stats.error_count);
+    }
+
+    printf("\n\n");
+}
+
+void print_message(Message kind, const char *fmt, ...) {
+    const char *accent_color = RESET;
+    const char *kind_text = "unknown";
+    switch (kind) {
+        case Info:
+            kind_text = "info";
+            accent_color = CYAN;
+            break;
+        case Warning:
+            kind_text = "warning";
+            accent_color = YELLOW;
+            break;
+        case Error:
+            kind_text = "error";
+            accent_color = RED;
+            break;
+    }
+
+    va_list args;
+    va_start(args, fmt);
+
+    printf("%s%s:%s ", accent_color, kind_text, RESET);
+    vprintf(fmt, args);
+    printf("\n");
+
+    va_end(args);
+}
+
+int create_directory(const char *path) {
+    assert(path != NULL);
+
+    DEBUG("creating directory: %s", path);
+
+    int result;
+#ifdef __unix__
+    result = mkdir(path, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
+#elif defined(_WIN32) || defined(WIN32)
+    result = _mkdir(path);
+#endif
+
+    return result;
+}
+
+const char *get_last_error() {
+    return strdup(strerror(errno));
+}
+
+const char *get_absolute_path(const char *path) {
+    assert(path != NULL);
+
+    DEBUG("resolving absolute path of: %s", path);
+
+#ifdef __unix__
+    // use unix specific function
+    char absolute_path[MAX_PATH_BYTES];
+    realpath(path, absolute_path);
+#elif defined(_WIN32) || defined(WIN32)
+    // use Windows CRT specific function
+    char absolute_path[MAX_PATH_BYTES];
+    _fullpath(path, absolute_path, _MAX_PATH);
+#endif
+
+    return strdup(absolute_path);
+}
+
+const char* make_file_path(const char* name, const char* ext, int count, ...) {
+    DEBUG("building file path...");
+
+    va_list args;
+    va_start(args, count); // Initialize the va_list with the first variadic argument
+
+    char* path = calloc(MAX_PATH_BYTES, sizeof(char));
+
+    for (int i = 0; i < count; i++) {
+        const char* arg = va_arg(args, const char*);
+        assert(arg != NULL);
+
+        strcat(path, arg);
+        strcat(path, PATH_SEPARATOR);
+    }
+
+    va_end(args); // Clean up the va_list
+
+    if (name != NULL) {
+        strcat(path, name);
+    }
+
+    if (name != NULL) {
+        strcat(path, ext);
+    }
+
+    return path;
+}
diff --git a/src/io/files.h b/src/io/files.h
new file mode 100644
index 0000000..61c7ebb
--- /dev/null
+++ b/src/io/files.h
@@ -0,0 +1,156 @@
+//
+// Created by servostar on 5/30/24.
+//
+
+#ifndef GEMSTONE_FILES_H
+#define GEMSTONE_FILES_H
+
+#include <stdio.h>
+#include <glib.h>
+
+#if defined(WIN32) || defined(_WIN32)
+#define PATH_SEPARATOR "\\"
+#else
+#define PATH_SEPARATOR "/"
+#endif
+
+typedef struct FileDiagnosticStatistics_t {
+    size_t error_count;
+    size_t warning_count;
+    size_t info_count;
+} FileDiagnosticStatistics;
+
+typedef struct ModuleFile_t {
+    const char *path;
+    FILE *handle;
+    FileDiagnosticStatistics statistics;
+} ModuleFile;
+
+typedef struct ModuleFileStack_t {
+    GArray *files;
+} ModuleFileStack;
+
+typedef enum Message_t {
+    Info,
+    Warning,
+    Error
+} Message;
+
+typedef struct TokenLocation_t {
+    unsigned long int line_start;
+    unsigned long int col_start;
+    unsigned long int line_end;
+    unsigned long int col_end;
+} TokenLocation;
+
+/**
+ * @brief Create a new, empty file stack.
+ * @return
+ */
+ModuleFileStack new_file_stack();
+
+/**
+ * @brief Add a new file to the file stack.
+ * @attention The file handle returned will be invalid
+ * @param stack
+ * @param path
+ * @return A new file module
+ */
+[[gnu::nonnull(1), gnu::nonnull(2)]]
+ModuleFile *push_file(ModuleFileStack *stack, const char *path);
+
+/**
+ * @brief Delete all files in the stack and the stack itself
+ * @param stack
+ */
+[[gnu::nonnull(1)]]
+void delete_files(ModuleFileStack *stack);
+
+/**
+ * Create a new token location
+ * @param line_start
+ * @param col_start
+ * @param line_end
+ * @param col_end
+ * @return
+ */
+TokenLocation new_location(unsigned long int line_start, unsigned long int col_start, unsigned long int line_end,
+                           unsigned long int col_end);
+
+/**
+ * @brief Create a new empty location with all of its contents set to zero
+ * @return
+ */
+TokenLocation empty_location(void);
+
+/**
+ * @brief Prints some diagnostic message to stdout.
+ *        This also print the token group and the attached source as context.
+ * @param file
+ * @param location
+ * @param kind
+ * @param message
+ */
+[[gnu::nonnull(1), gnu::nonnull(2)]]
+void print_diagnostic(ModuleFile *file, TokenLocation *location, Message kind, const char *message);
+
+[[gnu::nonnull(2)]]
+/**
+ * @brief Print a general message to stdout. Provides no source context like print_diagnostic()
+ * @param kind
+ * @param fmt
+ * @param ...
+ */
+void print_message(Message kind, const char *fmt, ...);
+
+/**
+ * @brief Print statistics about a specific file.
+ *        Will print the amount of infos, warning and errors emitted during compilation.
+ * @param file
+ */
+[[gnu::nonnull(1)]]
+void print_file_statistics(ModuleFile *file);
+
+/**
+ * @brief Print statistics of all files in the module stack.
+ * @param file_stack
+ */
+[[gnu::nonnull(1)]]
+void print_unit_statistics(ModuleFileStack *file_stack);
+
+/**
+ * @brief Create a new directory. Will return EEXISTS in case the directory already exists.
+ * @param path
+ * @return 0 if successful, anything else otherwise
+ */
+[[gnu::nonnull(1)]]
+int create_directory(const char* path);
+
+/**
+ * @brief Get a string describing the last error set by errno.
+ * @return a string that must be freed
+ */
+[[nodiscard("pointer must be freed")]]
+const char* get_last_error();
+
+/**
+ * @brief Resolve the absolute path from a given relative path.
+ * @param path
+ * @return
+ */
+[[gnu::nonnull(1)]]
+[[nodiscard("pointer must be freed")]]
+const char* get_absolute_path(const char* path);
+
+/**
+ * @brief Create a file path from a base name, extension a variable amount of directory path segments.
+ * @param count Amount of path segments to prepend to the basename
+ * @param name Basename of the file
+ * @param ext Extension of the file
+ * @param ... Path segments without path separator
+ * @return A relative path of a file
+ */
+[[nodiscard("pointer must be freed")]]
+const char* make_file_path(const char* name, const char* ext, int count, ...);
+
+#endif //GEMSTONE_FILES_H
diff --git a/src/lex/lexer.l b/src/lex/lexer.l
index 3df609f..af4dc21 100644
--- a/src/lex/lexer.l
+++ b/src/lex/lexer.l
@@ -52,6 +52,7 @@
 "float" {DEBUG("\"%s\" tokenized with \'KeyFloat\'", yytext); return(KeyFloat);};
 "self" {DEBUG("\"%s\" tokenized with \'KeySelf\'", yytext); return(KeySelf);};
 "as" {DEBUG("\"%s\" tokenized with \'KeyAs'", yytext); return (KeyAs);};
+"to" {DEBUG("\"%s\" tokenized with \'KeyTo'", yytext); return (KeyTo);};
 "short" {DEBUG("\"%s\" tokenized with \'KeyShort\'", yytext); return(KeyShort);};
 "long" {DEBUG("\"%s\" tokenized with \'KeyLong\'", yytext); return(KeyLong);};
 "half" {DEBUG("\"%s\" tokenized with \'KeyHalf\'", yytext); return(KeyHalf);};
@@ -97,7 +98,7 @@
     yytext[yyleng - 2] = 0;
     
     DEBUG("\"%s\" tokenized with \'ValStr\'", yytext); yylval.string = strdup(yytext); return(ValStr);};
-\"\"\"([^\"\n]|\\\n)*\"\"\" {
+\"\"\"[^\"]*\"\"\" {
     yytext = yytext +3;
     yytext[yyleng - 6] = 0;
 
diff --git a/src/lex/util.c b/src/lex/util.c
index b5b92ac..81f2855 100644
--- a/src/lex/util.c
+++ b/src/lex/util.c
@@ -25,6 +25,16 @@ void lex_init(void) {
   atexit(lex_deinit);
 }
 
+void lex_reset(void) {
+    eof = 0;
+    nRow = 0;
+    nBuffer = 0;
+    lBuffer = 0;
+    nTokenStart = 0;
+    nTokenLength = 0;
+    nTokenNextStart = 0;
+}
+
 void beginToken(char *t) {
   nTokenStart = nTokenNextStart;
   nTokenLength = (int) strlen(t);
@@ -41,7 +51,7 @@ int nextChar(char *dst) {
 
   if (eof)
     return 0;
-  
+
   while (nBuffer >= lBuffer) {
     frc = getNextLine();
     if (frc != 0) {
@@ -57,7 +67,7 @@ int nextChar(char *dst) {
 
 int getNextLine(void) {
   char *p;
-  
+
   nBuffer = 0;
   nTokenStart = -1;
   nTokenNextStart = 1;
diff --git a/src/lex/util.h b/src/lex/util.h
index 12e0837..6939526 100644
--- a/src/lex/util.h
+++ b/src/lex/util.h
@@ -16,6 +16,8 @@ extern char* buffer;
  */
 void lex_init(void);
 
+void lex_reset(void);
+
 /**
  * @brief Begin counting a new token. This will fill the global struct yylloc.
  * @param t the text of the token. Must be null terminated
diff --git a/src/main.c b/src/main.c
index 9e349fe..1f315e1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,15 +1,10 @@
 #include <ast/ast.h>
 #include <stdlib.h>
 #include <sys/log.h>
-#include <yacc/parser.tab.h>
 #include <sys/col.h>
 #include <lex/util.h>
-#include <set/set.h>
-
-#define LOG_LEVEL LOG_LEVEL_DEBUG
-
-extern FILE *yyin;
-AST_NODE_PTR root;
+#include <cfg/opt.h>
+#include <compiler.h>
 
 /**
  * @brief Log a debug message to inform about beginning exit procedures
@@ -17,68 +12,50 @@ AST_NODE_PTR root;
  */
 void notify_exit(void) { DEBUG("Exiting gemstone..."); }
 
-/**
- * @brief Closes File after compiling.
- *
- */
-
-void close_file(void) {
-  if (NULL != yyin) {
-    fclose(yyin);
-  }
-}
-
 /**
  * @brief Run compiler setup here
  *
  */
-void setup(void) {
-  // setup preample
+void setup(int argc, char *argv[]) {
+    // setup preample
+    parse_options(argc, argv);
 
-  log_init();
-  DEBUG("starting gemstone...");
+    log_init();
+    DEBUG("starting gemstone...");
 
 #if LOG_LEVEL <= LOG_LEVEL_DEBUG
-  atexit(&notify_exit);
+    atexit(&notify_exit);
 #endif
 
-  // actual setup
-  AST_init();
+    // actual setup
+    AST_init();
 
-  col_init();
+    col_init();
 
-  lex_init();
+    lex_init();
 
-  DEBUG("finished starting up gemstone...");
+    DEBUG("finished starting up gemstone...");
 }
 
 int main(int argc, char *argv[]) {
+    if (argc <= 1) {
+        print_help();
+        exit(1);
+    }
 
-  setup();
-  atexit(close_file);
+    setup(argc, argv);
 
-  // Check for file input as argument
-  if (2 != argc) {
-    INFO("Usage: %s <filename>\n", argv[0]);
-    PANIC("No File could be found");
-  }
+    if (is_option_set("help")) {
+        print_help();
+        exit(0);
+    }
 
-  // filename as first argument
-  char *filename = argv[1];
+    if (is_option_set("version")) {
+        printf("Running GSC version %s\n", GSC_VERSION);
+        exit(0);
+    }
 
-  FILE *file = fopen(filename, "r");
-
-  if (NULL == file) {
-    PANIC("File couldn't be opened!");
-  }
-  yyin = file;
-
-  root = AST_new_node(AST_Module, NULL);
-  yyparse();
-  create_set(root);
-  FILE *output = fopen("test.txt", "w");
-  AST_fprint_graphviz(output, root);
-  fclose(output);
-  AST_delete_node(root);
-  return 0;
+    run_compiler();
+    
+    return 0;
 }
diff --git a/src/sys/log.c b/src/sys/log.c
index 0aeab5f..7dcf94e 100644
--- a/src/sys/log.c
+++ b/src/sys/log.c
@@ -4,14 +4,29 @@
 #include <stdlib.h>
 #include <sys/log.h>
 #include <assert.h>
+#include <string.h>
+#include <cfg/opt.h>
 
 static struct Logger_t {
     FILE** streams;
     size_t stream_count;
 } GlobalLogger;
 
-void log_init(void)
+int runtime_log_level = LOG_LEVEL_WARNING;
+
+void set_log_level(int level)
 {
+    runtime_log_level = level;
+}
+
+void log_init()
+{
+    if (is_option_set("verbose")) {
+        set_log_level(LOG_LEVEL_INFORMATION);
+    } else if (is_option_set("debug")) {
+        set_log_level(LOG_LEVEL_DEBUG);
+    }
+
     assert(LOG_DEFAULT_STREAM != NULL);
     log_register_stream(LOG_DEFAULT_STREAM);
 }
@@ -30,7 +45,7 @@ void log_register_stream(FILE* restrict stream)
         if (GlobalLogger.streams == NULL)
         {
             PANIC("failed to allocate stream buffer");
-        }   
+        }
     }
     else
     {
diff --git a/src/sys/log.h b/src/sys/log.h
index 6b8991d..6db8fe5 100644
--- a/src/sys/log.h
+++ b/src/sys/log.h
@@ -53,12 +53,22 @@ will not print.
 #define INFO(format, ...) __LOG(LOG_STRING_INFORMATION, LOG_LEVEL_INFORMATION, format"\n", ##__VA_ARGS__)
 #define DEBUG(format, ...) __LOG(LOG_STRING_DEBUG, LOG_LEVEL_DEBUG, format"\n", ##__VA_ARGS__)
 
+extern int runtime_log_level;
+
 #define __LOG(level, priority, format, ...) \
     do { \
         if (LOG_LEVEL <= priority) \
-            syslog_logf(level, __FILE_NAME__, __LINE__, __func__, format, ##__VA_ARGS__); \
+            if (runtime_log_level <= priority) \
+                syslog_logf(level, __FILE_NAME__, __LINE__, __func__, format, ##__VA_ARGS__); \
     } while(0)
 
+/**
+ * @brief Set the runtime log level. Must be one of: LOG_LEVEL_ERROR, LOG_LEVEL_WARNING,
+ *        LOG_LEVEL_INFORMATION, LOG_LEVEL_DEBUG
+ * @param level the new log level
+ */
+void set_log_level(int level);
+
 /**
  * @brief Log a message into all registered streams
  * 
diff --git a/src/yacc/parser.y b/src/yacc/parser.y
index 4b8c156..68c2dba 100644
--- a/src/yacc/parser.y
+++ b/src/yacc/parser.y
@@ -5,9 +5,9 @@
     #include <sys/log.h>
     #include <ast/ast.h>
     #include <sys/col.h>
-    
+    #include <io/files.h>
     extern int yylineno;
-
+    extern ModuleFile* current_file;
 
     int yyerror(const char*);
 
@@ -16,7 +16,8 @@
     
     extern int yylex();
     extern AST_NODE_PTR root;
-    
+
+    #define new_loc() new_location(yylloc.first_line, yylloc.first_column, yylloc.last_line, yylloc.last_column)
 }
 
 %union {
@@ -73,6 +74,7 @@
 %token KeyFloat
 %token KeySelf
 %token KeyAs
+%token KeyTo
 %token <string> ValInt
 %token <string> Ident
 %token <string> ValFloat 
@@ -129,8 +131,8 @@
 %left '+' '-'
 %left '*' '/'
 %left OpNot OpBitnot
-%left KeyAs
-%left '(' ')'
+%left KeyAs KeyTo
+%left '(' ')' '[' ']'
 
 %%
 program: program programbody {AST_push_node(root, $2); 
@@ -146,35 +148,43 @@ programbody: moduleimport {$$ = $1;}
 
 
 
-expr: ValFloat {$$ = AST_new_node(AST_Float, $1);}
-    | ValInt    {$$ = AST_new_node(AST_Int, $1);}
-    | ValMultistr   {$$ = AST_new_node(AST_String, $1);}
-    | ValStr    {$$ = AST_new_node(AST_String, $1);}
-    | Ident     {$$ = AST_new_node(AST_Ident, $1);}
+expr: ValFloat {$$ = AST_new_node(new_loc(), AST_Float, $1);}
+    | ValInt    {$$ = AST_new_node(new_loc(), AST_Int, $1);}
+    | ValMultistr   {$$ = AST_new_node(new_loc(), AST_String, $1);}
+    | ValStr    {$$ = AST_new_node(new_loc(), AST_String, $1);}
+    | Ident     {$$ = AST_new_node(new_loc(), AST_Ident, $1);}
     | operation {$$ = $1;}
     | boxaccess {$$ = $1;}
     | boxselfaccess{$$ = $1;}
     | typecast{$$ = $1;}
     | reinterpretcast{$$ = $1;}
+    | '(' expr ')' {$$=$2;}
+    | KeyRef Ident {AST_NODE_PTR addrof = AST_new_node(new_loc(), AST_AddressOf, NULL);
+                                   AST_push_node(addrof, AST_new_node(new_loc(), AST_Ident, $2));
+                                   $$ = addrof;}
+    | expr '[' expr ']' {AST_NODE_PTR deref = AST_new_node(new_loc(), AST_Dereference, NULL);
+                                   AST_push_node(deref, $1);
+                                   AST_push_node(deref, $3);
+                                   $$ = deref;};
 
 exprlist: expr ',' exprlist {AST_push_node($3, $1);
                              $$ = $3;}
-        | expr {AST_NODE_PTR list = AST_new_node(AST_ExprList, NULL);
+        | expr {AST_NODE_PTR list = AST_new_node(new_loc(), AST_ExprList, NULL);
                 AST_push_node(list, $1);
                 $$ = list;};
 
 argumentlist: argumentlist '(' exprlist ')' {AST_push_node($1, $3);
                                              $$ = $1;}
-    | '(' exprlist ')'{AST_NODE_PTR list = AST_new_node(AST_ArgList, NULL);
+    | '(' exprlist ')'{AST_NODE_PTR list = AST_new_node(new_loc(), AST_ArgList, NULL);
                 AST_push_node(list, $2);
                 $$ = list;}
     | argumentlist '(' ')'
-    | '(' ')'{AST_NODE_PTR list = AST_new_node(AST_ArgList, NULL);
+    | '(' ')'{AST_NODE_PTR list = AST_new_node(new_loc(), AST_ArgList, NULL);
               $$ = list;};
 
 
-fundef: KeyFun Ident paramlist '{' statementlist'}' {AST_NODE_PTR fun = AST_new_node(AST_Fun, NULL);
-                                                     AST_NODE_PTR ident = AST_new_node(AST_Ident, $2);
+fundef: KeyFun Ident paramlist '{' statementlist'}' {AST_NODE_PTR fun = AST_new_node(new_loc(), AST_Fun, NULL);
+                                                     AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $2);
                                                      AST_push_node(fun, ident);
                                                      AST_push_node(fun, $3);
                                                      AST_push_node(fun, $5);
@@ -184,66 +194,66 @@ fundef: KeyFun Ident paramlist '{' statementlist'}' {AST_NODE_PTR fun = AST_new_
 paramlist: paramlist '(' params ')' {AST_push_node($1, $3);
                                      $$ = $1;}
          |  paramlist '(' ')'{$$ = $1;}
-         | '(' params ')' {AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+         | '(' params ')' {AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                            AST_push_node(list, $2);
                            $$ = list;}
-         | '(' ')' {$$ = AST_new_node(AST_List, NULL);};
+         | '(' ')' {$$ = AST_new_node(new_loc(), AST_List, NULL);};
 
-params: IOqualifyier paramdecl ',' params {AST_NODE_PTR parameter = AST_new_node(AST_Parameter, NULL);
+params: IOqualifyier paramdecl ',' params {AST_NODE_PTR parameter = AST_new_node(new_loc(), AST_Parameter, NULL);
                                 AST_push_node(parameter, $1);
                                 AST_push_node(parameter, $2);
                                 AST_push_node($4, parameter);
                                 $$ = $4;}
-      | IOqualifyier paramdecl {AST_NODE_PTR list = AST_new_node(AST_ParamList, NULL);
-                                AST_NODE_PTR parameter = AST_new_node(AST_Parameter, NULL);
+      | IOqualifyier paramdecl {AST_NODE_PTR list = AST_new_node(new_loc(), AST_ParamList, NULL);
+                                AST_NODE_PTR parameter = AST_new_node(new_loc(), AST_Parameter, NULL);
                                 AST_push_node(parameter, $1);
                                 AST_push_node(parameter, $2);
                                 AST_push_node(list, parameter);
                                 $$ = list;};
 
-IOqualifyier: KeyIn { AST_NODE_PTR in = AST_new_node(AST_Qualifyier, "in");
-                      AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+IOqualifyier: KeyIn { AST_NODE_PTR in = AST_new_node(new_loc(), AST_Qualifyier, "in");
+                      AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                       AST_push_node(list, in);
                       $$ = list;}
-            | KeyOut{ AST_NODE_PTR out = AST_new_node(AST_Qualifyier, "out");
-                      AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+            | KeyOut{ AST_NODE_PTR out = AST_new_node(new_loc(), AST_Qualifyier, "out");
+                      AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                       AST_push_node(list, out);
                       $$ = list;}
-            | KeyIn KeyOut{ AST_NODE_PTR in = AST_new_node(AST_Qualifyier, "in");
-                      AST_NODE_PTR out = AST_new_node(AST_Qualifyier, "out");
-                      AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+            | KeyIn KeyOut{ AST_NODE_PTR in = AST_new_node(new_loc(), AST_Qualifyier, "in");
+                      AST_NODE_PTR out = AST_new_node(new_loc(), AST_Qualifyier, "out");
+                      AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                       AST_push_node(list, in);
                       AST_push_node(list, out);
                       $$ = list;}
-            | KeyOut KeyIn{ AST_NODE_PTR in = AST_new_node(AST_Qualifyier, "in");
-                      AST_NODE_PTR out = AST_new_node(AST_Qualifyier, "out");
-                      AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+            | KeyOut KeyIn{ AST_NODE_PTR in = AST_new_node(new_loc(), AST_Qualifyier, "in");
+                      AST_NODE_PTR out = AST_new_node(new_loc(), AST_Qualifyier, "out");
+                      AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                       AST_push_node(list, in);
                       AST_push_node(list, out);
                       $$ = list;}
-            | {$$ = AST_new_node(AST_List, NULL);};
+            | {$$ = AST_new_node(new_loc(), AST_List, NULL);};
 
-paramdecl: type ':' Ident { AST_NODE_PTR paramdecl = AST_new_node(AST_ParamDecl, NULL);
+paramdecl: type ':' Ident { AST_NODE_PTR paramdecl = AST_new_node(new_loc(), AST_ParamDecl, NULL);
                             AST_push_node(paramdecl, $1);
-                            AST_NODE_PTR ident = AST_new_node(AST_Ident, $3);
+                            AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $3);
                             AST_push_node(paramdecl, ident);
                             $$ = paramdecl;
     DEBUG("Param-Declaration"); };
 
-box: KeyType KeyBox ':' Ident '{' boxbody '}' {AST_NODE_PTR box = AST_new_node(AST_Box, NULL);
-                                       AST_NODE_PTR ident = AST_new_node(AST_Ident, $4);
+box: KeyType KeyBox ':' Ident '{' boxbody '}' {AST_NODE_PTR box = AST_new_node(new_loc(), AST_Box, NULL);
+                                       AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $4);
                                        AST_push_node(box, ident);
                                        AST_push_node(box, $6);
                                        $$ = box; 
     DEBUG("Box"); }
-   | KeyType KeyBox ':' Ident '{' '}' {AST_NODE_PTR box = AST_new_node(AST_Box, NULL);
-                                       AST_NODE_PTR ident = AST_new_node(AST_Ident, $4);
+   | KeyType KeyBox ':' Ident '{' '}' {AST_NODE_PTR box = AST_new_node(new_loc(), AST_Box, NULL);
+                                       AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $4);
                                        AST_push_node(box, ident);
                                        $$ = box;};
 
 boxbody: boxbody boxcontent {AST_push_node($1, $2);
                              $$ = $1;}
-       | boxcontent {AST_NODE_PTR list = AST_new_node(AST_List, NULL);
+       | boxcontent {AST_NODE_PTR list = AST_new_node(new_loc(), AST_List, NULL);
                      AST_push_node(list, $1);
                      $$ = list;};
 
@@ -251,66 +261,66 @@ boxcontent: decl { $$ = $1;DEBUG("Box decl Content"); }
           | definition { $$ = $1;DEBUG("Box def Content"); }
           | fundef { $$ = $1;DEBUG("Box fun Content"); };
 
-boxselfaccess: KeySelf '.' Ident {AST_NODE_PTR boxselfaccess = AST_new_node(AST_List, NULL);
-                                      AST_NODE_PTR self = AST_new_node(AST_Ident, "self");
+boxselfaccess: KeySelf '.' Ident {AST_NODE_PTR boxselfaccess = AST_new_node(new_loc(), AST_List, NULL);
+                                      AST_NODE_PTR self = AST_new_node(new_loc(), AST_Ident, "self");
                                       AST_push_node(boxselfaccess, self);
-                                      AST_NODE_PTR identlist = AST_new_node(AST_IdentList, NULL);
-                                      AST_NODE_PTR ident = AST_new_node(AST_Ident, $3);
+                                      AST_NODE_PTR identlist = AST_new_node(new_loc(), AST_IdentList, NULL);
+                                      AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $3);
                                       AST_push_node(identlist,ident);
                                       AST_push_node(boxselfaccess, identlist);
                                       $$ = boxselfaccess;}
-             | KeySelf '.' boxaccess {AST_NODE_PTR boxselfaccess = AST_new_node(AST_List, NULL);
-                                      AST_NODE_PTR self = AST_new_node(AST_Ident, "self");
+             | KeySelf '.' boxaccess {AST_NODE_PTR boxselfaccess = AST_new_node(new_loc(), AST_List, NULL);
+                                      AST_NODE_PTR self = AST_new_node(new_loc(), AST_Ident, "self");
                                       AST_push_node(boxselfaccess, self);
                                       AST_push_node(boxselfaccess, $3);
                                       $$ = boxselfaccess;};
 
-boxaccess: Ident '.' Ident {AST_NODE_PTR identlist = AST_new_node(AST_IdentList, NULL);
-                                      AST_NODE_PTR ident1 = AST_new_node(AST_Ident, $1);
-                                      AST_NODE_PTR ident2 = AST_new_node(AST_Ident, $3);
+boxaccess: Ident '.' Ident {AST_NODE_PTR identlist = AST_new_node(new_loc(), AST_IdentList, NULL);
+                                      AST_NODE_PTR ident1 = AST_new_node(new_loc(), AST_Ident, $1);
+                                      AST_NODE_PTR ident2 = AST_new_node(new_loc(), AST_Ident, $3);
                                       AST_push_node(identlist,ident1);
                                       AST_push_node(identlist,ident2);
                                       $$ = identlist;}
-         | Ident '.' boxaccess {AST_NODE_PTR ident = AST_new_node(AST_Ident, $1);
+         | Ident '.' boxaccess {AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $1);
                                       AST_push_node($3,ident);
                                       $$ = $3;};
 
-boxcall: boxaccess argumentlist {AST_NODE_PTR boxcall = AST_new_node(AST_Call, NULL);
+boxcall: boxaccess argumentlist {AST_NODE_PTR boxcall = AST_new_node(new_loc(), AST_Call, NULL);
                                  AST_push_node(boxcall, $1);
                                  AST_push_node(boxcall, $2);
                                  $$ = boxcall;}
-       | boxselfaccess argumentlist {AST_NODE_PTR boxcall = AST_new_node(AST_Call, NULL);
+       | boxselfaccess argumentlist {AST_NODE_PTR boxcall = AST_new_node(new_loc(), AST_Call, NULL);
                                  AST_push_node(boxcall, $1);
                                  AST_push_node(boxcall, $2);
                                  $$ = boxcall;};
                                  
 
-typecast: expr KeyAs type %prec KeyAs  {AST_NODE_PTR cast = AST_new_node(AST_Typecast, NULL);
+typecast: expr KeyAs type %prec KeyAs  {AST_NODE_PTR cast = AST_new_node(new_loc(), AST_Typecast, NULL);
                                         AST_push_node(cast, $1);
                                         AST_push_node(cast, $3);
                                         $$ = cast;
                                          DEBUG("Type-Cast"); };
 
-reinterpretcast: '(' type ')' expr { AST_NODE_PTR cast = AST_new_node(AST_Transmute, NULL);
-                                      AST_push_node(cast, $4);
-                                        AST_push_node(cast, $2);
+reinterpretcast: expr KeyTo type %prec KeyTo { AST_NODE_PTR cast = AST_new_node(new_loc(), AST_Transmute, NULL);
+                                      AST_push_node(cast, $1);
+                                        AST_push_node(cast, $3);
                                         $$ = cast;
                                     DEBUG("Reinterpret-Cast"); };
 
 
-funcall: Ident argumentlist {AST_NODE_PTR funcall = AST_new_node(AST_Call, NULL);
-                             AST_NODE_PTR ident = AST_new_node(AST_Ident, $1);
+funcall: Ident argumentlist {AST_NODE_PTR funcall = AST_new_node(new_loc(), AST_Call, NULL);
+                             AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $1);
                              AST_push_node(funcall, ident);
                              AST_push_node(funcall, $2);
                              $$ = funcall;
                              DEBUG("Function call"); };
 
-moduleimport: KeyImport ValStr {$$ = AST_new_node(AST_Import, $2);
+moduleimport: KeyImport ValStr {$$ = AST_new_node(new_loc(), AST_Import, $2);
                                  DEBUG("Module-Import"); };
 
 statementlist: statementlist statement  {AST_push_node($1, $2);
                                         $$ = $1;}
-    | statement {AST_NODE_PTR list = AST_new_node(AST_StmtList, NULL);
+    | statement {AST_NODE_PTR list = AST_new_node(new_loc(), AST_StmtList, NULL);
                  AST_push_node(list, $1);
         $$ = list;};
 
@@ -322,16 +332,16 @@ statement: assign {$$ = $1;}
         | funcall {$$ = $1;}
         | boxcall{$$ = $1;};
 
-branchif: KeyIf expr '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(AST_If, NULL);
+branchif: KeyIf expr '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(new_loc(), AST_If, NULL);
                                             AST_push_node(branch, $2);
                                             AST_push_node(branch, $4);
                                             $$ = branch; };
 
-branchelse: KeyElse '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(AST_Else, NULL);
+branchelse: KeyElse '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(new_loc(), AST_Else, NULL);
                                             AST_push_node(branch, $3);
                                             $$ = branch; };
 
-branchelseif: KeyElse KeyIf expr '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(AST_IfElse, NULL);
+branchelseif: KeyElse KeyIf expr '{' statementlist '}' { AST_NODE_PTR branch = AST_new_node(new_loc(), AST_IfElse, NULL);
                                             AST_push_node(branch, $3);
                                             AST_push_node(branch, $5);
                                             $$ = branch; };
@@ -339,49 +349,49 @@ branchelseif: KeyElse KeyIf expr '{' statementlist '}' { AST_NODE_PTR branch = A
 branchfull:  branchhalf { $$ = $1;};
             |branchhalf branchelse {   AST_push_node($1 , $2);
                                 $$ = $1; }
-branchhalf:  branchif  { AST_NODE_PTR branch = AST_new_node(AST_Stmt, NULL);
+branchhalf:  branchif  { AST_NODE_PTR branch = AST_new_node(new_loc(), AST_Stmt, NULL);
                                 AST_push_node(branch, $1);
                                 $$ = branch; }
         | branchhalf branchelseif { AST_push_node($1 , $2);
                                 $$ = $1; };
 
 
-while: KeyWhile expr '{' statementlist '}' {AST_NODE_PTR whilenode = AST_new_node(AST_While, NULL);
+while: KeyWhile expr '{' statementlist '}' {AST_NODE_PTR whilenode = AST_new_node(new_loc(), AST_While, NULL);
                                 AST_push_node(whilenode, $2);
                                 AST_push_node(whilenode, $4);
                                 $$ = whilenode;};
 
-identlist: Ident ',' identlist {AST_NODE_PTR ident = AST_new_node(AST_Ident, $1);
+identlist: Ident ',' identlist {AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $1);
                                 AST_push_node($3, ident);
                                 $$ = $3;}
-        | Ident {AST_NODE_PTR list = AST_new_node(AST_IdentList, NULL);
-                 AST_NODE_PTR ident = AST_new_node(AST_Ident, $1);
+        | Ident {AST_NODE_PTR list = AST_new_node(new_loc(), AST_IdentList, NULL);
+                 AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $1);
                  AST_push_node(list, ident);
                  $$ = list;};               
 
-decl: type ':' identlist {AST_NODE_PTR decl = AST_new_node(AST_Decl, NULL);
+decl: type ':' identlist {AST_NODE_PTR decl = AST_new_node(new_loc(), AST_Decl, NULL);
                           AST_push_node(decl, $1);
                           AST_push_node(decl, $3);
                           $$ = decl;}
-    | storagequalifier type ':' identlist {AST_NODE_PTR decl = AST_new_node(AST_Decl, NULL);
+    | storagequalifier type ':' identlist {AST_NODE_PTR decl = AST_new_node(new_loc(), AST_Decl, NULL);
                                            AST_push_node(decl, $1);
                                            AST_push_node(decl, $2);
                                            AST_push_node(decl, $4);
                                            $$ = decl;};
 
 
-definition: decl '=' expr { AST_NODE_PTR def = AST_new_node(AST_Def, NULL);
+definition: decl '=' expr { AST_NODE_PTR def = AST_new_node(new_loc(), AST_Def, NULL);
                             AST_push_node(def, $1);
                             AST_push_node(def, $3);
                             $$ = def;
     DEBUG("Definition"); };
 
-storagequalifier: KeyGlobal {$$ = AST_new_node(AST_Storage, "global");}
-        | KeyStatic {$$ = AST_new_node(AST_Storage, "static");}
-        | KeyLocal {$$ = AST_new_node(AST_Storage, "local");};
+storagequalifier: KeyGlobal {$$ = AST_new_node(new_loc(), AST_Storage, "global");}
+        | KeyStatic {$$ = AST_new_node(new_loc(), AST_Storage, "static");}
+        | KeyLocal {$$ = AST_new_node(new_loc(), AST_Storage, "local");};
 
-assign: Ident '=' expr { AST_NODE_PTR assign = AST_new_node(AST_Assign, NULL);
-                         AST_NODE_PTR ident = AST_new_node(AST_Ident, $1);
+assign: Ident '=' expr { AST_NODE_PTR assign = AST_new_node(new_loc(), AST_Assign, NULL);
+                         AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $1);
                          AST_push_node(assign, ident);
                          AST_push_node(assign, $3);
                          $$ = assign;
@@ -390,200 +400,141 @@ assign: Ident '=' expr { AST_NODE_PTR assign = AST_new_node(AST_Assign, NULL);
       | boxaccess '=' expr 
       | boxselfaccess '=' expr ;
 
-sign: KeySigned {$$ = AST_new_node(AST_Sign, "signed");}
-    | KeyUnsigned{$$ = AST_new_node(AST_Sign, "unsigned");};
+sign: KeySigned {$$ = AST_new_node(new_loc(), AST_Sign, "signed");}
+    | KeyUnsigned{$$ = AST_new_node(new_loc(), AST_Sign, "unsigned");};
 
-typedef: KeyType type':' Ident {AST_NODE_PTR typeDef = AST_new_node(AST_Typedef, NULL);
+typedef: KeyType type':' Ident {AST_NODE_PTR typeDef = AST_new_node(new_loc(), AST_Typedef, NULL);
                                 AST_push_node(typeDef, $2);
-                                AST_NODE_PTR ident = AST_new_node(AST_Ident, $4);
+                                AST_NODE_PTR ident = AST_new_node(new_loc(), AST_Ident, $4);
                                 AST_push_node(typeDef, ident);
                                 $$ = typeDef;};
 
-scale: scale KeyShort {AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "short");
+scale: scale KeyShort {AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "short");
                        AST_push_node($1, shortnode);
                        $$ = $1;}
-    | scale KeyHalf {AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "half");
+    | scale KeyHalf {AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "half");
                        AST_push_node($1, shortnode);
                        $$ = $1;}
-    | scale KeyLong {AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "long");
+    | scale KeyLong {AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "long");
                        AST_push_node($1, shortnode);
                        $$ = $1;}
-    | scale KeyDouble {AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "double");
+    | scale KeyDouble {AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "double");
                        AST_push_node($1, shortnode);
                        $$ = $1;}
-    | KeyShort {AST_NODE_PTR scale = AST_new_node(AST_List, NULL);
-                AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "short");
+    | KeyShort {AST_NODE_PTR scale = AST_new_node(new_loc(), AST_List, NULL);
+                AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "short");
                 AST_push_node(scale, shortnode);
                 $$ = scale;}
-    | KeyHalf {AST_NODE_PTR scale = AST_new_node(AST_List, NULL);
-                AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "half");
+    | KeyHalf {AST_NODE_PTR scale = AST_new_node(new_loc(), AST_List, NULL);
+                AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "half");
                 AST_push_node(scale, shortnode);
                 $$ = scale;}
-    | KeyLong {AST_NODE_PTR scale = AST_new_node(AST_List, NULL);
-                AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "long");
+    | KeyLong {AST_NODE_PTR scale = AST_new_node(new_loc(), AST_List, NULL);
+                AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "long");
                 AST_push_node(scale, shortnode);
                 $$ = scale;}
-    | KeyDouble {AST_NODE_PTR scale = AST_new_node(AST_List, NULL);
-                AST_NODE_PTR shortnode = AST_new_node(AST_Scale, "double");
+    | KeyDouble {AST_NODE_PTR scale = AST_new_node(new_loc(), AST_List, NULL);
+                AST_NODE_PTR shortnode = AST_new_node(new_loc(), AST_Scale, "double");
                 AST_push_node(scale, shortnode);
                 $$ = scale;};
 
-typekind: Ident {$$ = AST_new_node(AST_Typekind, $1);}
-    | KeyInt {$$ = AST_new_node(AST_Typekind, "int");}
-    | KeyFloat {$$ = AST_new_node(AST_Typekind, "float");};
+typekind: Ident {$$ = AST_new_node(new_loc(), AST_Typekind, $1);}
+    | KeyInt {$$ = AST_new_node(new_loc(), AST_Typekind, "int");}
+    | KeyFloat {$$ = AST_new_node(new_loc(), AST_Typekind, "float");};
 
-type: typekind {AST_NODE_PTR type = AST_new_node(AST_Type, NULL);
+type: typekind {AST_NODE_PTR type = AST_new_node(new_loc(), AST_Type, NULL);
                 AST_push_node(type, $1);
                 $$ = type;}
-    | scale typekind {AST_NODE_PTR type = AST_new_node(AST_Type, NULL);
+    | scale typekind {AST_NODE_PTR type = AST_new_node(new_loc(), AST_Type, NULL);
                 AST_push_node(type, $1);
                 AST_push_node(type, $2);
                 $$ = type;}
-    | sign typekind {AST_NODE_PTR type = AST_new_node(AST_Type, NULL);
+    | sign typekind {AST_NODE_PTR type = AST_new_node(new_loc(), AST_Type, NULL);
                 AST_push_node(type, $1);
                 AST_push_node(type, $2);
                 $$ = type;}
-    | sign scale typekind {AST_NODE_PTR type = AST_new_node(AST_Type, NULL);
+    | sign scale typekind {AST_NODE_PTR type = AST_new_node(new_loc(), AST_Type, NULL);
                 AST_push_node(type, $1);
                 AST_push_node(type, $2);
                 AST_push_node(type, $3);
-                $$ = type;};
+                $$ = type;}
+    | KeyRef type {AST_NODE_PTR reftype = AST_new_node(new_loc(), AST_Reference, NULL);
+               AST_push_node(reftype, $2);
+               $$ = reftype; };
 
 operation: oparith {$$ = $1;}
     | oplogic {$$ = $1;}
     | opbool {$$ = $1;}
     | opbit {$$ = $1;};
 
-oparith: expr '+' expr {AST_NODE_PTR add = AST_new_node(AST_Add, NULL);
+oparith: expr '+' expr {AST_NODE_PTR add = AST_new_node(new_loc(), AST_Add, NULL);
                         AST_push_node(add, $1);
                         AST_push_node(add, $3);
                         $$ = add;}
-    | expr '-' expr    {AST_NODE_PTR subtract = AST_new_node(AST_Sub, NULL);
+    | expr '-' expr    {AST_NODE_PTR subtract = AST_new_node(new_loc(), AST_Sub, NULL);
                         AST_push_node(subtract, $1);
                         AST_push_node(subtract, $3);
                         $$ = subtract;}
-    | expr '*' expr     {AST_NODE_PTR mul = AST_new_node(AST_Mul, NULL);
+    | expr '*' expr     {AST_NODE_PTR mul = AST_new_node(new_loc(), AST_Mul, NULL);
                         AST_push_node(mul, $1);
                         AST_push_node(mul, $3);
                         $$ = mul;}
-    | expr '/' expr     {AST_NODE_PTR div = AST_new_node(AST_Div, NULL);
+    | expr '/' expr     {AST_NODE_PTR div = AST_new_node(new_loc(), AST_Div, NULL);
                         AST_push_node(div, $1);
                         AST_push_node(div, $3);
                         $$ = div;}
-    | '-' expr %prec '*'{AST_NODE_PTR negator = AST_new_node(AST_Negate, NULL);
+    | '-' expr %prec '*'{AST_NODE_PTR negator = AST_new_node(new_loc(), AST_Negate, NULL);
                         AST_push_node(negator, $2);
                         $$ = negator;};
 
-oplogic: expr OpEquals expr {AST_NODE_PTR equals = AST_new_node(AST_Eq, NULL);
+oplogic: expr OpEquals expr {AST_NODE_PTR equals = AST_new_node(new_loc(), AST_Eq, NULL);
                              AST_push_node(equals, $1);
                              AST_push_node(equals, $3);
                              $$ = equals;}
-    | expr '<' expr {AST_NODE_PTR less = AST_new_node(AST_Less, NULL);
+    | expr '<' expr {AST_NODE_PTR less = AST_new_node(new_loc(), AST_Less, NULL);
                              AST_push_node(less, $1);
                              AST_push_node(less, $3);
                              $$ = less;}
-    | expr '>' expr{AST_NODE_PTR greater = AST_new_node(AST_Greater, NULL);
+    | expr '>' expr{AST_NODE_PTR greater = AST_new_node(new_loc(), AST_Greater, NULL);
                              AST_push_node(greater, $1);
                              AST_push_node(greater, $3);
                              $$ = greater;};
 
-opbool: expr OpAnd expr {AST_NODE_PTR and = AST_new_node(AST_BoolAnd, NULL);
+opbool: expr OpAnd expr {AST_NODE_PTR and = AST_new_node(new_loc(), AST_BoolAnd, NULL);
                              AST_push_node(and, $1);
                              AST_push_node(and, $3);
                              $$ = and;}
-    | expr OpOr expr{AST_NODE_PTR or = AST_new_node(AST_BoolOr, NULL);
+    | expr OpOr expr{AST_NODE_PTR or = AST_new_node(new_loc(), AST_BoolOr, NULL);
                              AST_push_node(or, $1);
                              AST_push_node(or, $3);
                              $$ = or;}
-    | expr OpXor expr{AST_NODE_PTR xor = AST_new_node(AST_BoolXor, NULL);
+    | expr OpXor expr{AST_NODE_PTR xor = AST_new_node(new_loc(), AST_BoolXor, NULL);
                              AST_push_node(xor, $1);
                              AST_push_node(xor, $3);
                              $$ = xor;}
-    | OpNot expr %prec OpAnd{AST_NODE_PTR not = AST_new_node(AST_BoolNot, NULL);
+    | OpNot expr %prec OpAnd{AST_NODE_PTR not = AST_new_node(new_loc(), AST_BoolNot, NULL);
                              AST_push_node(not, $2);
                              $$ = not;};
 
-opbit: expr OpBitand expr {AST_NODE_PTR and = AST_new_node(AST_BitAnd, NULL);
+opbit: expr OpBitand expr {AST_NODE_PTR and = AST_new_node(new_loc(), AST_BitAnd, NULL);
                              AST_push_node(and, $1);
                              AST_push_node(and, $3);
                              $$ = and;}
-    | expr OpBitor expr{AST_NODE_PTR or = AST_new_node(AST_BitOr, NULL);
+    | expr OpBitor expr{AST_NODE_PTR or = AST_new_node(new_loc(), AST_BitOr, NULL);
                              AST_push_node(or, $1);
                              AST_push_node(or, $3);
                              $$ = or;}
-    | expr OpBitxor expr{AST_NODE_PTR xor = AST_new_node(AST_BitXor, NULL);
+    | expr OpBitxor expr{AST_NODE_PTR xor = AST_new_node(new_loc(), AST_BitXor, NULL);
                              AST_push_node(xor, $1);
                              AST_push_node(xor, $3);
                              $$ = xor;}
-    | OpBitnot expr %prec OpBitand{AST_NODE_PTR not = AST_new_node(AST_BitNot, NULL);
+    | OpBitnot expr %prec OpBitand{AST_NODE_PTR not = AST_new_node(new_loc(), AST_BitNot, NULL);
                              AST_push_node(not, $2);
                              $$ = not;};
 %%
 
- 
-const char* ERROR = "error";
-const char* WARNING = "warning";
-const char* NOTE = "note";
-
-int print_message(const char* kind, const char* message) {
-    // number of characters written
-    int char_count = 0;
-    // highlight to use
-    char* HIGHLIGHT = CYAN;
-
-    // convert message kind into color
-    if (kind == ERROR) {
-        HIGHLIGHT = RED;
-    } else if (kind == WARNING) {
-        HIGHLIGHT = YELLOW;
-    }
-
-    // print message
-    char_count += printf("%sfilename:%d:%d%s:%s%s %s: %s%s\n", BOLD, yylloc.first_line, yylloc.first_column, RESET, HIGHLIGHT, BOLD, kind, RESET, message);
-    
-    // print line in which error occurred
-    
-    char_count += printf(" %4d | ", yylloc.first_line);
-
-    for (int i = 0; i < yylloc.first_column - 1; i++) {
-        if (buffer[i] == '\n') {
-            break;
-        }
-        printf("%c", buffer[i]);
-    }
-
-    char_count += printf("%s%s", BOLD, HIGHLIGHT);
-
-    for (int i = yylloc.first_column - 1; i < yylloc.last_column; i++) {
-        if (buffer[i] == '\n') {
-            break;
-        }
-        char_count += printf("%c", buffer[i]);
-    }
-
-    char_count += printf("%s", RESET);
-
-    for (int i = yylloc.last_column; buffer[i] != '\0' && buffer[i] != '\n'; i++) {
-        printf("%c", buffer[i]);
-    }
-
-    char_count += printf("\n      | ");
-
-    for (int i = 0; i < yylloc.first_column - 1; i++) {
-        char_count += printf(" ");
-    }
-
-    char_count += printf("%s^", HIGHLIGHT);
-
-    for (int i = 0; i < yylloc.last_column - yylloc.first_column; i++) {
-        printf("~");
-    }
-    
-    char_count += printf("%s\n\n", RESET);
-
-    return char_count;
-}
-
 int yyerror(const char *s) {
-    return print_message(ERROR, s);
+    TokenLocation location = new_loc();
+    print_diagnostic(current_file, &location, Error, s);
+    return 0;
 }
\ No newline at end of file
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1228d2b..761b32c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -9,4 +9,5 @@ set(CTEST_BINARY_DIRECTORY ${PROJECT_BINARY_DIR}/tests)
 add_subdirectory(logging)
 add_subdirectory(input_file)
 add_subdirectory(ast)
-add_subdirectory(glib)
\ No newline at end of file
+add_subdirectory(glib)
+add_subdirectory(project)
\ No newline at end of file
diff --git a/tests/ast/CMakeLists.txt b/tests/ast/CMakeLists.txt
index 455130b..5bd19b6 100644
--- a/tests/ast/CMakeLists.txt
+++ b/tests/ast/CMakeLists.txt
@@ -2,6 +2,20 @@ include(CTest)
 
 include_directories(${PROJECT_SOURCE_DIR}/src)
 
+# ------------------------------------------------ #
+# Setup Glib 2.0                                   #
+# ------------------------------------------------ #
+
+find_package(PkgConfig REQUIRED)
+pkg_search_module(GLIB REQUIRED IMPORTED_TARGET glib-2.0)
+include_directories(PRIVATE ${GLIB_INCLUDE_DIRS})
+
+# ------------------------------------------------ #
+# Setup TOML-C99                                   #
+# ------------------------------------------------ #
+
+include_directories(${PROJECT_SOURCE_DIR}/dep/tomlc99)
+
 # ------------------------------------------------------- #
 # CTEST 1
 # test building the syntax tree
@@ -9,11 +23,16 @@ include_directories(${PROJECT_SOURCE_DIR}/src)
 add_executable(ast_build_tree
         ${PROJECT_SOURCE_DIR}/src/ast/ast.c
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/dep/tomlc99/toml.c
         build_tree.c)
 set_target_properties(ast_build_tree
         PROPERTIES
         OUTPUT_NAME "build_tree"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/ast)
+target_link_libraries(ast_build_tree PkgConfig::GLIB)
 add_test(NAME ast_build_tree
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/ast/test_ast.py check_build_tree)
@@ -25,11 +44,16 @@ add_test(NAME ast_build_tree
 add_executable(ast_print_node
         ${PROJECT_SOURCE_DIR}/src/ast/ast.c
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/dep/tomlc99/toml.c
         print_node.c)
 set_target_properties(ast_print_node
         PROPERTIES
         OUTPUT_NAME "print_node"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/ast)
+target_link_libraries(ast_print_node PkgConfig::GLIB)
 add_test(NAME ast_print_node
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/ast/test_ast.py check_print_node)
@@ -41,11 +65,16 @@ add_test(NAME ast_print_node
 add_executable(ast_graphviz
         ${PROJECT_SOURCE_DIR}/src/ast/ast.c
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/dep/tomlc99/toml.c
         print_graphviz.c)
 set_target_properties(ast_graphviz
         PROPERTIES
         OUTPUT_NAME "print_graphviz"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/ast)
+target_link_libraries(ast_graphviz PkgConfig::GLIB)
 add_test(NAME ast_graphviz
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/ast/test_ast.py check_print_graphviz)
diff --git a/tests/ast/build_tree.c b/tests/ast/build_tree.c
index dec7b85..2d2459b 100644
--- a/tests/ast/build_tree.c
+++ b/tests/ast/build_tree.c
@@ -6,22 +6,22 @@
 #include <sys/log.h>
 
 void generate_statement(const AST_NODE_PTR stmt) {
-    const AST_NODE_PTR add = AST_new_node(AST_Add, NULL);
+    const AST_NODE_PTR add = AST_new_node(empty_location(), AST_Add, NULL);
 
-    AST_push_node(add, AST_new_node(AST_Int, "3"));
-    AST_push_node(add, AST_new_node(AST_Int, "6"));
+    AST_push_node(add, AST_new_node(empty_location(), AST_Int, "3"));
+    AST_push_node(add, AST_new_node(empty_location(), AST_Int, "6"));
 
     AST_push_node(stmt, add);
 }
 
 void generate_branch(const AST_NODE_PTR stmt) {
-    const AST_NODE_PTR branch = AST_new_node(AST_If, NULL);
-    const AST_NODE_PTR gt = AST_new_node(AST_Greater, NULL);
+    const AST_NODE_PTR branch = AST_new_node(empty_location(), AST_If, NULL);
+    const AST_NODE_PTR gt = AST_new_node(empty_location(), AST_Greater, NULL);
 
     AST_push_node(branch, gt);
 
-    AST_push_node(gt, AST_new_node(AST_Float, "2.3"));
-    AST_push_node(gt, AST_new_node(AST_Float, "0.79"));
+    AST_push_node(gt, AST_new_node(empty_location(), AST_Float, "2.3"));
+    AST_push_node(gt, AST_new_node(empty_location(), AST_Float, "0.79"));
 
     AST_push_node(stmt, branch);
 
@@ -30,7 +30,7 @@ void generate_branch(const AST_NODE_PTR stmt) {
 
 int main(void) {
 
-    const AST_NODE_PTR root = AST_new_node(AST_Stmt, NULL);
+    const AST_NODE_PTR root = AST_new_node(empty_location(), AST_Stmt, NULL);
 
     generate_branch(root);
 
diff --git a/tests/ast/gen_graph.c b/tests/ast/gen_graph.c
index 186d571..c4e2f92 100644
--- a/tests/ast/gen_graph.c
+++ b/tests/ast/gen_graph.c
@@ -7,15 +7,15 @@
 
 int main(void) {
 
-    struct AST_Node_t* node = AST_new_node(AST_If, NULL);
+    struct AST_Node_t* node = AST_new_node(empty_location(), AST_If, NULL);
 
-    struct AST_Node_t* child = AST_new_node(AST_Add, NULL);
-    AST_push_node(child, AST_new_node(AST_Int, "43"));
-    AST_push_node(child, AST_new_node(AST_Int, "9"));
+    struct AST_Node_t* child = AST_new_node(empty_location(), AST_Add, NULL);
+    AST_push_node(child, AST_new_node(empty_location(), AST_Int, "43"));
+    AST_push_node(child, AST_new_node(empty_location(), AST_Int, "9"));
 
     AST_push_node(node, child);
-    AST_push_node(node, AST_new_node(AST_Expr, NULL));
-    AST_push_node(node, AST_new_node(AST_Expr, NULL));
+    AST_push_node(node, AST_new_node(empty_location(), AST_Expr, NULL));
+    AST_push_node(node, AST_new_node(empty_location(), AST_Expr, NULL));
 
     FILE* out = fopen("ast.gv", "w+");
     // convert this file        ^^^^^^
diff --git a/tests/ast/print_graphviz.c b/tests/ast/print_graphviz.c
index 6df64b4..c0f69af 100644
--- a/tests/ast/print_graphviz.c
+++ b/tests/ast/print_graphviz.c
@@ -6,22 +6,22 @@
 #include <sys/log.h>
 
 void generate_statement(const AST_NODE_PTR stmt) {
-    const AST_NODE_PTR add = AST_new_node(AST_Add, NULL);
+    const AST_NODE_PTR add = AST_new_node(empty_location(), AST_Add, NULL);
 
-    AST_push_node(add, AST_new_node(AST_Int, "3"));
-    AST_push_node(add, AST_new_node(AST_Int, "6"));
+    AST_push_node(add, AST_new_node(empty_location(), AST_Int, "3"));
+    AST_push_node(add, AST_new_node(empty_location(), AST_Int, "6"));
 
     AST_push_node(stmt, add);
 }
 
 void generate_branch(const AST_NODE_PTR stmt) {
-    const AST_NODE_PTR branch = AST_new_node(AST_If, NULL);
-    const AST_NODE_PTR gt = AST_new_node(AST_Greater, NULL);
+    const AST_NODE_PTR branch = AST_new_node(empty_location(), AST_If, NULL);
+    const AST_NODE_PTR gt = AST_new_node(empty_location(), AST_Greater, NULL);
 
     AST_push_node(branch, gt);
 
-    AST_push_node(gt, AST_new_node(AST_Float, "2.3"));
-    AST_push_node(gt, AST_new_node(AST_Float, "0.79"));
+    AST_push_node(gt, AST_new_node(empty_location(), AST_Float, "2.3"));
+    AST_push_node(gt, AST_new_node(empty_location(), AST_Float, "0.79"));
 
     AST_push_node(stmt, branch);
 
@@ -32,7 +32,7 @@ int main(void) {
 
     AST_init();
 
-    const AST_NODE_PTR root = AST_new_node(AST_Stmt, NULL);
+    const AST_NODE_PTR root = AST_new_node(empty_location(), AST_Stmt, NULL);
 
     generate_branch(root);
 
diff --git a/tests/ast/print_node.c b/tests/ast/print_node.c
index 38e8a41..47db685 100644
--- a/tests/ast/print_node.c
+++ b/tests/ast/print_node.c
@@ -8,7 +8,7 @@ int main(void) {
 
     AST_init();
 
-    const AST_NODE_PTR node = AST_new_node(0, "value");
+    const AST_NODE_PTR node = AST_new_node(empty_location(), 0, "value");
 
     for (size_t i = 0; i < AST_ELEMENT_COUNT; i++) {
         // set kind
diff --git a/tests/ast/test_ast.py b/tests/ast/test_ast.py
index e3e5d48..d7f9665 100644
--- a/tests/ast/test_ast.py
+++ b/tests/ast/test_ast.py
@@ -81,6 +81,9 @@ def run_check_print_node():
 50 parameter
 51 value
 52 parameter-declaration
+53 address of
+54 deref
+55 ref
 """ == p.stdout
 
 
diff --git a/tests/input_file/test_input_file.py b/tests/input_file/test_input_file.py
index 3721dc0..550f3f4 100644
--- a/tests/input_file/test_input_file.py
+++ b/tests/input_file/test_input_file.py
@@ -12,7 +12,7 @@ def check_accept():
 
     test_file_name = sys.argv[1]
 
-    p = subprocess.run(["./gsc", test_file_name], capture_output=True, text=True)
+    p = subprocess.run(["./gsc", "compile", test_file_name], capture_output=True, text=True)
 
     assert p.returncode == 0
 
@@ -22,7 +22,7 @@ def check_abort():
 
     logging.basicConfig(level=logging.INFO)
 
-    p = subprocess.run("./gsc", capture_output=True, text=True)
+    p = subprocess.run(["./gsc", "compile"], capture_output=True, text=True)
 
     assert p.returncode == 1
 
diff --git a/tests/logging/CMakeLists.txt b/tests/logging/CMakeLists.txt
index 0f14079..2bfa385 100644
--- a/tests/logging/CMakeLists.txt
+++ b/tests/logging/CMakeLists.txt
@@ -2,17 +2,36 @@ include(CTest)
 
 include_directories(${PROJECT_SOURCE_DIR}/src)
 
+# ------------------------------------------------ #
+# Setup Glib 2.0                                   #
+# ------------------------------------------------ #
+
+find_package(PkgConfig REQUIRED)
+pkg_search_module(GLIB REQUIRED IMPORTED_TARGET glib-2.0)
+include_directories(PRIVATE ${GLIB_INCLUDE_DIRS})
+
+# ------------------------------------------------ #
+# Setup TOML-C99                                   #
+# ------------------------------------------------ #
+
+include_directories(${PROJECT_SOURCE_DIR}/dep/tomlc99)
+
 # ------------------------------------------------------- #
 # CTEST 1
 # test the default output of the logger
 
 add_executable(logging_output
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
         output.c)
 set_target_properties(logging_output
         PROPERTIES
         OUTPUT_NAME "output"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/logging)
+target_link_libraries(logging_output PkgConfig::GLIB)
+target_link_libraries(logging_output tomlc99)
 add_test(NAME logging_output
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/logging/test_logging.py check_output)
@@ -23,11 +42,16 @@ add_test(NAME logging_output
 
 add_executable(logging_panic
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
         panic.c)
 set_target_properties(logging_panic
         PROPERTIES
         OUTPUT_NAME "panic"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/logging)
+target_link_libraries(logging_panic PkgConfig::GLIB)
+target_link_libraries(logging_panic tomlc99)
 add_test(NAME logging_panic
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/logging/test_logging.py check_panic)
@@ -38,11 +62,16 @@ add_test(NAME logging_panic
 
 add_executable(logging_streams
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
         streams.c)
 set_target_properties(logging_streams
         PROPERTIES
         OUTPUT_NAME "stream"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/logging)
+target_link_libraries(logging_streams PkgConfig::GLIB)
+target_link_libraries(logging_streams tomlc99)
 add_test(NAME logging_streams
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/logging/test_logging.py check_stream)
@@ -53,11 +82,16 @@ add_test(NAME logging_streams
 
 add_executable(logging_level
         ${PROJECT_SOURCE_DIR}/src/sys/log.c
+        ${PROJECT_SOURCE_DIR}/src/sys/col.c
+        ${PROJECT_SOURCE_DIR}/src/cfg/opt.c
+        ${PROJECT_SOURCE_DIR}/src/io/files.c
         level.c)
 set_target_properties(logging_level
         PROPERTIES
         OUTPUT_NAME "level"
         RUNTIME_OUTPUT_DIRECTORY ${GEMSTONE_BINARY_DIR}/tests/logging)
+target_link_libraries(logging_level PkgConfig::GLIB)
+target_link_libraries(logging_level tomlc99)
 add_test(NAME logging_level
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         COMMAND python ${GEMSTONE_TEST_DIR}/logging/test_logging.py check_level)
diff --git a/tests/logging/level.c b/tests/logging/level.c
index 6a4f055..ed89205 100644
--- a/tests/logging/level.c
+++ b/tests/logging/level.c
@@ -3,11 +3,16 @@
 //
 
 #include "sys/log.h"
+#include <sys/col.h>
+#include <cfg/opt.h>
 
 #define LOG_LEVEL LOG_LEVEL_WARNING
 
-int main(void) {
+int main(int argc, char* argv[]) {
+    parse_options(argc, argv);
     log_init();
+    set_log_level(LOG_LEVEL_DEBUG);
+    col_init();
 
     DEBUG("logging some debug...");
     INFO("logging some info...");
diff --git a/tests/logging/output.c b/tests/logging/output.c
index 7accfc5..a6cfdb2 100644
--- a/tests/logging/output.c
+++ b/tests/logging/output.c
@@ -3,9 +3,14 @@
 //
 
 #include "sys/log.h"
+#include <sys/col.h>
+#include <cfg/opt.h>
 
-int main(void) {
+int main(int argc, char* argv[]) {
+    parse_options(argc, argv);
     log_init();
+    set_log_level(LOG_LEVEL_DEBUG);
+    col_init();
 
     DEBUG("logging some debug...");
     INFO("logging some info...");
diff --git a/tests/logging/panic.c b/tests/logging/panic.c
index ecd8815..f64f3a1 100644
--- a/tests/logging/panic.c
+++ b/tests/logging/panic.c
@@ -3,9 +3,12 @@
 //
 
 #include "sys/log.h"
+#include <cfg/opt.h>
 
-int main(void) {
+int main(int argc, char* argv[]) {
+    parse_options(argc, argv);
     log_init();
+    set_log_level(LOG_LEVEL_DEBUG);
 
     // this should appear in stderr
     INFO("before exit");
diff --git a/tests/logging/streams.c b/tests/logging/streams.c
index 97599da..5dd7cc2 100644
--- a/tests/logging/streams.c
+++ b/tests/logging/streams.c
@@ -4,6 +4,7 @@
 
 #include "sys/log.h"
 #include <stdlib.h>
+#include <cfg/opt.h>
 
 static FILE* file;
 
@@ -13,8 +14,10 @@ void close_file(void) {
     }
 }
 
-int main(void) {
+int main(int argc, char* argv[]) {
+    parse_options(argc, argv);
     log_init();
+    set_log_level(LOG_LEVEL_DEBUG);
 
     // this should appear in stderr
     INFO("should only be in stderr");
diff --git a/tests/project/CMakeLists.txt b/tests/project/CMakeLists.txt
new file mode 100644
index 0000000..2a8d3d6
--- /dev/null
+++ b/tests/project/CMakeLists.txt
@@ -0,0 +1,9 @@
+include(CTest)
+
+# ------------------------------------------------------- #
+# CTEST 1
+# test if the program successfully reads the project config
+
+add_test(NAME project_build
+        WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/tests/project
+        COMMAND python ${GEMSTONE_TEST_DIR}/project/test_project.py)
diff --git a/tests/project/build.toml b/tests/project/build.toml
new file mode 100644
index 0000000..772f9a5
--- /dev/null
+++ b/tests/project/build.toml
@@ -0,0 +1,15 @@
+[project]
+authors = [ "Sven Vogel" ]
+license = "GPL-2.0"
+version = "0.1.0"
+description = "This is a test project"
+
+[target.debug]
+root = "src/main.txt"
+output = "bin"
+archive = "archive"
+opt = 1
+print_ast = true
+print_asm = true
+print_ir = true
+mode = "application"
diff --git a/tests/project/src/main.txt b/tests/project/src/main.txt
new file mode 100644
index 0000000..3e3c969
--- /dev/null
+++ b/tests/project/src/main.txt
@@ -0,0 +1,4 @@
+
+fun main(out int: e) {
+    e = 0
+}
\ No newline at end of file
diff --git a/tests/project/test_project.py b/tests/project/test_project.py
new file mode 100644
index 0000000..1815c1c
--- /dev/null
+++ b/tests/project/test_project.py
@@ -0,0 +1,15 @@
+import subprocess
+import logging
+from logging import info, error
+
+if __name__ == "__main__":
+    info("started check output...")
+
+    p = subprocess.run([ "../../bin/debug/gsc", "build", "all" ], capture_output=True, text=True)
+
+    info("checking exit code...")
+
+    print(p.stdout)
+
+    # check exit code
+    assert p.returncode == 0