Syntax

Walrus uses a compact typed surface syntax with explicit module headers and colon-delimited blocks.

File structure

Most source files start like this:

module Showcase
@strict
import Math
import Gameplay

Then come module constants, type declarations, and functions.

Comments

Walrus supports two comment forms:

# single line comment

<#
block comment
#>

Statements

Common statement forms are:

• let for local or module constants
• var for mutable locals
• assignment
• if / else
• while
• switch / case / default
• return
• nested fn declarations inside functions
• expression statements

Example:

fn main() -> int:
    let total = 0
    var i = 0

    while i < 10:
        if i == 5:
            i += 1
        else:
            total += i
            i += 1

    return total

Types

Builtin type names are lowercase:

• int
• float
• bool
• string

Walrus also uses explicit function and ownership-aware types:

fn makeAdder(k: int) -> fn(int) -> int
let view: ref string = text
let sharedNode: shared<UiNode> = uiRoot

Literals and expressions

Supported literal forms include:

• integers like 0, 42, -3
• floats like 2.0, 3.1415926
• strings like "walrus says hi"
• booleans true and false
• arrays like [1, 2, 3]
• object literals like { x = 1, y = 2 }
• enum members like Team.Red

Common operators:

• arithmetic: +, -, *, /
• compound assignment: +=, -=
• comparisons: ==, <, <=, >, >=
• logical and: &&
• indexing: a[i]
• property access: o.x
• calls: f(1, 2)