GALA-E0091 — Constant does not fit its type

When it fires. An untyped constant written with literals takes the type of the position it fills, and that type cannot hold it. The position is the other operand of a binary operator (x * 1.5 for an int x) or a slot whose type is known: an argument, a declaration, a field. The constant does not fit when it is:

a number with a fractional part where an integer type is expected (1.5 for an int);
a number out of the integer type’s range (300 for a byte);
a number where a string or bool is expected, or a string where a number or bool is.

Minimal repro.

package main

func main() {
    val x = 3
    Println(x * 1.5)
}

Error output.

error[GALA-E0091]: the constant 1.5 cannot be an int, the type of the other operand of *: it is not a whole number
  --> main.gala:5:17
  |
5 |     Println(x * 1.5)
  |                 ^^^ convert the other operand to the type you mean
  |
  = hint: convert the other operand to the type you mean (e.g. `float64(x)`); GALA converts no number implicitly

Fix. Convert the other operand, so both have the type you mean:

package main

func main() {
    val x = 3
    Println(float64(x) * 1.5)
}

Or write a constant the type holds (x * 2), or declare the value with the type you mean (val x = 3.0).

Rationale. GALA follows Go’s rules for untyped constants and converts no number implicitly: x * 1.5 would silently change either the constant or the type of x. Such code used to pass GALA and fail in go build, which reported “1.5 (untyped float constant) truncated to int” against the generated code.

Type Inference — how an untyped constant takes its type
All GALA error codes

GALA-E0091 — Constant does not fit its type

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