is_null() — internals

is_null() — internals

Where it lives

• Signature: src/builtins/types/is_null.rs
• Lowering: src/codegen/lower_inst/builtins.rs:1611 (lower_is_null_builtin)
• Function symbol: lower_is_null_builtin()

Lowering notes

• Lowers is_null() for concrete scalar values and boxed Mixed payloads.

Runtime helpers

No direct __rt_* helpers captured — the lowering is inlined or routes through another builtin.

Signature summary

function is_null(mixed $value): bool

What the type checker enforces

• Arity: takes exactly 1 argument.

Eval interpreter (magician)

• Declaration: crates/elephc-magician/src/interpreter/builtins/types/is_null.rs (eval_builtin!)
• Dispatch hooks: direct, values

Cross-references

• User reference for is_null()