2. Values and operators

This lesson is verified against Zryna 0.2.1 from 841c8aee901782c9f7bf442bfe8eb2fe6b7f6446. The exact operator semantics live in the release’s M2_JAVASCRIPT_BACKEND.md and matching WebAssembly backend.

Open tutorial-control/src/scalars.zry:

export function calculate(start: i32, step: i32): i32 {
  let total: i32 = start;
  const doubled: i32 = step * 2;
  total = total + doubled;
  return total - 1;
}

export function isAtLeast(left: i32, right: i32): bool {
  return left >= right;
}

Types and bindings

• i32 is a signed 32-bit integer. Published arithmetic wraps to its low 32 bits.
• bool has exactly true and false; numeric truthiness is not accepted.
• const creates an initialized binding that cannot be assigned again.
• let creates an initialized mutable binding. Assignment must keep the exact type.

The published scalar operators are unary -, integer +, -, *, signed <, <=, >, >=, and exact === and !== for equal scalar types. This preview does not admit division, remainder, coercing equality, or untyped numbers in this profile.

Run a Boolean export

& $zryna run src/scalars.zry `
  --project-root "$workspace\tutorial-control" `
  --profile control-flow-v1 `
  --target javascript `
  --name comparison-1 `
  --export isAtLeast `
  --arg=i32:9 `
  --arg=i32:4

Expected output:

javascript: bool true

Typed arguments are strict. Use canonical forms such as i32:-1, i32:0, and bool:false; 01, +1, fractions, and True are rejected.

Common errors

• Assigning to const is rejected. Use let only when the algorithm needs reassignment.
• Assigning a bool to an i32 (or the reverse) is an exact-type error; there is no implicit conversion.
• Arithmetic overflow wraps for i32; it does not widen to a JavaScript number.

Exercise

Run isAtLeast on both targets with left = -3 and right = 2. Then run it with equal values. Use new output names for every run.

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