array_unshift() — internals

array_unshift() — internals

Where it lives

• Signature: src/builtins/array/array_unshift.rs
• Lowering: src/builtins/semantics.rs:639 (lower_registry_call)
• Function symbol: lower_registry_call()

Lowering notes

• Uses the runtime_call strategy from the single-source builtin descriptor.
• Emits the typed EIR target runtime.array_unshift through BuiltinLoweringContext.
• The backend resolves that typed target through src/codegen/lower_inst/runtime_calls.rs; PHP builtin names do not participate in dispatch.

Semantic descriptor

• Target strategy: runtime_call
• Validation: checker_hook
• Result type source: checked
• Result ownership: may_alias_arguments
• Effects: static (16 declared effects)
• Requirements: static (0 requirements)
• Callable policy: static_only
• Target support: macos-aarch64, ios-arm64, ios-sim-arm64, linux-aarch64, linux-x86_64

EIR and runtime boundary

• Typed EIR target: runtime.array_unshift
• Backend boundary: src/codegen/lower_inst/runtime_calls.rs resolves the typed target without PHP-name dispatch.

Signature summary

function array_unshift(array $array, ...$values): int

What the type checker enforces

• Arity: takes exactly 1 argument.
• By-reference parameters: $array.
• Variadic: collects excess arguments into $values.

Eval interpreter (magician)

• Declaration: crates/elephc-magician/src/interpreter/builtins/array/array_unshift.rs (eval_builtin!)
• Execution: Magician interpreter adapter.
• Adapter reason: by-reference-or-lvalue.
• Dispatch hooks: values
• By-reference parameters: $array.
• Variadic: collects excess arguments into $values.

Cross-references

• User reference for array_unshift()