63 lines
2.9 KiB
Markdown
63 lines
2.9 KiB
Markdown
## Yard
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Yard is an funny programming language compiler and interpreter written in pure Rust.
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Its a functional language, having no concept of classes or inheritance. Types are static and must be known at compile time.
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### Primitve data types
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The language has 4 primitive data types:
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* `bool` a 1 byte boolean value which is either true or false. It can also be initalised with a random value at compile time iwht `maybe`
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* `int` a 8 byte two's complement signed integer with 64-bit of storage space
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* `rat` a 8 byte IEEE-754 double precision floating point value
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* `str` a dynamically sized immutable string wich for now can only be used with the concatonation operator `..`
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NOTE: no custom data types such as structs or classes are supported.
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### Keywords
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<table><tbody><tr><td>Syntax</td><td>Description</td><td>Example</td></tr><tr><td>despite</td><td>Inverted if. Only executes the following block if the expression is false</td><td><pre><code class="language-plaintext">despite 3 > 4 {
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// code block
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}</code></pre></td></tr><tr><td>loop</td><td>While(true)-Loop. Loops forever until either yield, ret, break are used.<br>Loop take no boolean expression.</td><td><pre><code class="language-plaintext">loop {
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// code block
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}</code></pre></td></tr><tr><td>cont</td><td>Short form for “continue”. Jumps to the next iteration of a loop</td><td><pre><code class="language-plaintext">loop {
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cont;
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}</code></pre></td></tr><tr><td>break</td><td>Exits a loop immediately</td><td><pre><code class="language-plaintext">loop {
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break;
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}</code></pre></td></tr><tr><td>yield</td><td>Returns from a function with an argument as return value</td><td><pre><code class="language-plaintext">foo() = int {
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yield 4
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}</code></pre></td></tr><tr><td>ret</td><td>Short form for “return”. This keyword takes no argument and returns from a function. NOTE: if ret is used in a function with a return type, an error occurs.</td><td><pre><code class="language-plaintext">foo() {
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ret // exit function
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}</code></pre></td></tr><tr><td>please</td><td>Decides on runtime wether a block should be executed or not.</td><td><pre><code class="language-plaintext">please {
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// code
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}</code></pre></td></tr><tr><td>unless</td><td>Works like a while loop except inverted. it will only run if the condition is false.</td><td><pre><code class="language-plaintext">unless x > 5 {
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// code
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}</code></pre></td></tr><tr><td>goto</td><td>jumps to a specified label</td><td><pre><code class="language-plaintext">'label
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// code
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goto label;</code></pre></td></tr></tbody></table>
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### Example code
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```plaintext
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-- compute the factorial
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-- in a recursive and functional way
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fac(x:int) = int {
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despite x != 1 {
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yield 1;
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}
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yield fac(x - 1) * x
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}
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number = rat 34 # this is a function without arguments and a braceless body
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// main function
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main = int {
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result = fac(number);
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println("The Factorial of " .. number .. " is: " .. result);
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yield 0;
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}
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``` |