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GALA-E0008 — Map literal not supported

What it means. The source uses a Go-style map literal (map[K]V{…}) as an expression. Maps, like slices, are not a first-class GALA construct.

Code that triggers it

package main

func main() {
    val m = map[string]int{"a": 1, "b": 2}
    Println(m)
}

Compiler message

error[GALA-E0008]: map literals are not a first-class GALA construct
  --> e0008.gala:4:13
  |
4 |     val m = map[string]int{"a": 1, "b": 2}
  |             ^^^ use collection_immutable.HashMap or collection_mutable.HashM…
  |
  = hint: use collection_immutable.HashMap or collection_mutable.HashMap for type-safe maps, or go_interop.MapEmpty()/MapPut() for Go interop

How to fix it

import . "martianoff/gala/collection_immutable"
import "martianoff/gala/go_interop"

val m = HashMapOf(("a", 1), ("b", 2))                            // immutable GALA map
val g = go_interop.MapPut(go_interop.MapEmpty[string, int](), "a", 1)   // raw Go map

Why the rule exists

Same reasoning as GALA-E0007: GALA reasons about its own map types. Raw Go map literals erase the GALA-side invariants — an immutable HashMap can be shared without defensive copies, a Go map cannot. Forcing the caller to name one of the two supported paths keeps that distinction visible at the call site.