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diff --git a/docs/00.html b/docs/00.html new file mode 100644 index 0000000..cd0c352 --- /dev/null +++ b/docs/00.html @@ -0,0 +1,61 @@ +<h2>Declarations</h2> + +<p>In toc, declarations have the following syntax: +<code> +<name> :[:] [type] [= expression]; +</code></p> + +<p>The square brackets (<code>[]</code>) indicate something optional.</p> + +<p>All of the following statements +declare an new variable <code>x</code> which is an integer, and has a value of 0: +<code> +x : int; +x : int = 0; +x := 0; +</code> +Note that in the first of those statements, although no expression +is specified, it defaults to 0. This is not true in C, +and there will eventually probably be an option to +leave <code>x</code> uninitialized.</p> + +<p>If you wanted x to be a floating-point number, you could use: +<code> +x : float; +x : float = 0; +x := 0.0; +</code></p> + +<p>Note that <code>0</code> can be used as both a <code>float</code> and an <code>int</code>eger, but +when no type is specified, it defaults to an <code>int</code>, whereas <code>0.0</code> +defaults to a <code>float</code>.</p> + +<p>Here are all of toc's builtin types and their ranges of values:</p> + +<ul> +<li><code>int</code> - A 64-bit signed integer (always), -9223372036854775808 to 9223372036854775807</li> +<li><code>i8</code> - An 8-bit signed integer, -128 to 128</li> +<li><code>i16</code> - 16-bit signed integer, -32768 to 32767</li> +<li><code>i32</code> - 32-bit signed integer, -2147483648 to 2147483647</li> +<li><code>i64</code> - 64-bit signed integer (same as <code>int</code>, but more explicit about the size), -9223372036854775808 to 9223372036854775807</li> +<li><code>u8</code> - An 8-bit unsigned integer, 0 to 255</li> +<li><code>u16</code> - 16-bit unsigned integer, 0 to 65535</li> +<li><code>u32</code> - 32-bit unsigned integer, 0 to 4294967295</li> +<li><code>u64</code> - 64-bit unsigned integer, 0 to 18446744073709551615</li> +<li><code>float</code> - A 32-bit floating-point number, -3.40282347e+38 to 3.40282347e+38</li> +<li><code>f32</code> - A 32-bit floating-point number (same as <code>float</code>, but more explicit about the size)</li> +<li><code>f64</code> - A 64-bit floating-point number, -1.7976931348623157e+308 to 1.7976931348623157e+308</li> +<li><code>bool</code> - A boolean value, either <code>false</code> or <code>true</code>.</li> +<li><code>char</code> - A character. The specific values are technically platform-dependent, but usually there are 256 of them.</li> +</ul> + +<p>At the moment, it is not technically guaranteed that <code>f32</code>/<code>float</code> is actually 32-bit and that <code>f64</code> is actually 64-bit; they are platform dependent. Perhaps someday there will be a version of toc which does not compile to C, where that could be guaranteed.</p> + +<p>To make declarations constant, use <code>::</code> instead of <code>:</code>. e.g.</p> + +<p><code> +x ::= 5+3; <br /> +y :: float = 5.123; +</code></p> + +<p>Here, "constant" means constant at compile time, not read-only as it does in C. One interesting thing about toc is that normal functions can run at compile time, so pretty much any expression is a valid initializer for a constant, e.g. doing <code>x ::= some_function();</code> runs <code>some_function</code> at compile time, not at run time.</p> |