phpdoc

const (
	// ExprInvalid represents "failed to parse" type expression.
	ExprInvalid ExprKind = iota

	// ExprUnknown is a garbage-prefixed type expression.
	// Examples: `-int` `@@\Foo[]`
	// Args[0] - a valid expression that follows invalid prefix
	ExprUnknown

	// ExprName is a type that is identified by its name.
	// Examples: `int` `\Foo\Bar` `$this`
	ExprName

	// ExprKeyword is a special name-like type node.
	// Examples: `*` `...`
	ExprSpecialName

	// ExprInt is a digit-only type expression.
	// Examples: `0` `10`
	ExprInt

	// ExprKeyVal is `key:val` type.
	// Examples: `name: string` `id:int`
	// Args[0] - key expression (left)
	// Args[1] - val expression (right)
	ExprKeyVal

	// ExprMemberType is access to member.
	// Examples: `\Foo::SOME_CONSTANT` `\Foo::$a`
	// Args[0] - class type expression (left)
	// Args[1] - member name expression (right)
	ExprMemberType

	// ExprArray is `elem[]` or `[]elem` type.
	// Examples: `int[]` `(int|float)[]` `int[`
	// Args[0] - array element type
	// ShapeArrayPrefix: `[]T`
	//
	// Note: may miss second `]`.
	ExprArray

	// ExprParen is `(expr)` type.
	// Examples: `(int)` `(\Foo\Bar[])` `(int`
	// Args[0] - enclosed type
	//
	// Note: may miss closing `)`.
	ExprParen

	// ExprNullable is `?expr` type.
	// Examples: `?int` `?\Foo`
	// Args[0] - nullable element type
	ExprNullable

	// ExprOptional is `expr?` type.
	// Examples: `k?: int`
	// Args[0] - optional element type
	ExprOptional

	// ExprNot is `!expr` type.
	// Examples: `!int` `!(int|float)`
	// Args[0] - negated element type
	//
	// Note: only valid for phpgrep type filters.
	ExprNot

	// ExprUnion is `x|y` type.
	// Examples: `T1|T2` `int|float[]|false`
	// Args - type variants
	ExprUnion

	// ExprInter is `x&y` type.
	// Examples: `T1&T2` `I1&I2&I3`
	ExprInter

	// ExprGeneric is a parametrized `expr<T,...>` type.
	// Examples: `\Collection<T>` `Either<int[], false>` `Bad<int`
	// Args[0] - parametrized type
	// Args[1:] - type parameters
	// ShapeGenericParen: `T(X,Y)`
	// ShapeGenericBrace: `T{X,Y}`
	//
	// Note: may miss closing `>`.
	ExprGeneric

	// ExprTypedCallable is a parametrized `callable(A,...):B` type.
	// Examples: `callable():void` `callable(int, int) : float`
	// Args[0] - return type
	// Args[1:] - argument types
	ExprTypedCallable
)

const (
	ShapeDefault ExprShape = iota
	ShapeArrayPrefix
	ShapeGenericParen
	ShapeGenericBrace
)