Syntax reference

The syntax is centered on a few explicit rules: typed functions, typed variables, simple expressions, and structured control flow.

Lexical shape

• Source files are plain text files with the .ark extension.
• Comments start with # and continue to the end of the line.
• Whitespace is used for readability and indentation in block-oriented code.

Declarations

Functions

Functions use fun, a name, a typed parameter list, and a return type annotation.

fun main() @u64:
    return 0

Parameters are written with a name followed by @type.

fun add(lhs @s32, rhs @s32) @s32:
    return lhs + rhs

Variables

Variables are declared with an explicit type annotation.

result @f32 = 0.0
flag @bool = true
count @s32 = 10

Assignments reuse the variable name without repeating the type.

result = result + 1.0

Types

The language uses a compact primitive type set:

• @s32
• @u32
• @u64
• @f32
• @f64
• @bool
• See more about types

Types are explicit in declarations, parameters, and return annotations.

Expressions

The language supports arithmetic, comparisons, logical operators, function calls, and explicit grouping with parentheses.

return (bar * foo2) + (foo2 < foo2)

Operators shown in the examples include:

• Arithmetic: +, -, *, /
• Comparison: <, <=, >, >=, ==, !=
• Boolean: &&, ||

Control flow

Conditionals and loops are block-oriented.

if foo1 > 5.0:
    foo1 = 0.0
else if foo1 >= 10.0:
    foo1 = 20.0
else:
    foo1 = 21.0

while n != 0:
    result = result * n
    n = n - 1

return exits the current function.

Literals

The language includes integer, floating-point, and boolean literals.

0
10.5
true
false

Example shape

This is a representative minimal program:

fun main() @s32:
    return 0

See example/test/test.ark for a broader sample that exercises functions, branches, loops, arithmetic, comparisons, logical expressions, and assignments.