Language: Arrow functions (fn() => expr)

[PurHur]

Problem

Short closures fn($x) => $x * 2 are not in compiler pipeline. Needed for array_map style callbacks in modern PHP.

Goal

Single-expression arrow functions with lexical use (phase 1: no use).

Tasks

• Compile to anonymous inner function / closure object
• VM callable representation
• JIT: defer to phase after closures (Language: Closures and anonymous functions #72)

Acceptance

$d = array_map(fn($x) => $x * 2, [1, 2, 3]);