Declarations

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<name> :[:] [type] [= expression];

The square brackets ([]) indicate something optional.

All of the following statements declare an new variable x which is an integer, and has a value of 0:

x : int;
x : int = 0;
x := 0;

If you wanted x to be a floating-point number, you could use:

x : float;
x : float = 0;
x := 0.0;

Note that 0 can be used as both a float and an integer, but when no type is specified, it defaults to an int, whereas 0.0 defaults to a float.

Here are all of toc's basic builtin types and their ranges of values:

• int - A 64-bit signed integer (always), -9223372036854775808 to 9223372036854775807
• i8 - An 8-bit signed integer, -128 to 128
• i16 - 16-bit signed integer, -32768 to 32767
• i32 - 32-bit signed integer, -2147483648 to 2147483647
• i64 - 64-bit signed integer (same as int, but more explicit about the size), -9223372036854775808 to 9223372036854775807
• u8 - An 8-bit unsigned integer, 0 to 255
• u16 - 16-bit unsigned integer, 0 to 65535
• u32 - 32-bit unsigned integer, 0 to 4294967295
• u64 - 64-bit unsigned integer, 0 to 18446744073709551615
• float - A 32-bit floating-point number, -3.40282347e+38 to 3.40282347e+38
• f32 - A 32-bit floating-point number (same as float, but more explicit about the size)
• f64 - A 64-bit floating-point number, -1.7976931348623157e+308 to 1.7976931348623157e+308
• bool - A boolean value, either false or true.
• char - A character (usually either -128 to 127 or 0 to 255).

To make declarations constant, use :: instead of :. e.g.

x ::= 5+3; y :: float = 5.123;

Here, "constant" means constant at compile time, not read-only as it does in C.