MEP-75 Phase 4: Closed PHP-to-Mochi Type Mapping Table

Status: LANDED 2026-05-30 00:00 (GMT+7)

Goal

Implement the closed PHP-to-Mochi type translation table under package3/php/typemap. Every PHP type must produce either a Mochi extern-type string or a SkipReason -- no open-ended inference.

Type Table

PHP Type	Mochi Type	Notes
int, integer	int	primitive
float, double	float	primitive
string	string	primitive
bool, boolean	bool	primitive
?T / T|null	T|nil	nullable wrapping
void (return)	unit	DirectionOut only
null	nil	literal null type
true, false	bool	singleton bool types
iterable	list[any]	coarse mapping
array<T>	list[T]	via MapTypedArray
array<K,V>	map[K]V	via MapTypedArray
FQCN	PascalCase handle	GuzzleHttp\Client -> GuzzleHttpClient
A|B	A|B	true union
mixed	--	SkipMixed
object	--	SkipObject
callable	--	SkipCallable
resource	--	SkipResource
never	--	SkipNever
self/static/parent	--	SkipSelfStatic
array (untyped)	--	SkipUntypedArray
A&B	--	SkipIntersection

Files Landed

• package3/php/typemap/typemap.go -- full implementation
• package3/php/typemap/typemap_test.go -- comprehensive test suite (15 test functions)

Test Coverage

• Primitives (all PHP aliases)
• Nullable wrapping (?T and T|null)
• Void return type (DirectionOut)
• All 8 SkipReason variants triggered by Map()
• Class handle generation (FQCN -> PascalCase)
• Nullable class handles
• Union degenerate (int|null -> int|nil)
• Union two types (int|string)
• Union with null (int|string|null)
• Union containing skip component
• Intersection type skip
• MapTypedArray list and map forms
• MapTypedArray propagates skip from value type
• Case-insensitive matching (INT, STRING, BOOL, FLOAT)
• classHandleType edge cases (empty, leading backslash, multi-segment)
• Mapping struct field verification