Useful traits for ast

traits.d

module d.convenience.traits;

import d.ir.expression;
import d.ir.type;

QualType elementType(Expression e)  {
	assert(isSliceOrArray(e) || isPointer(e), typeid(e.type.type).toString() ~ " has no elementType");
	return elementType(e.type);
}

QualType elementType(QualType qt)  {
	qt = peelAlias(qt);
	if(auto asSlice = cast(SliceType) qt.type) {
		return asSlice.sliced;
	} else if(auto asPointer = cast(PointerType) qt.type) {
		return asPointer.pointed;
	} else if(auto asArray = cast(ArrayType) qt.type) {
		return asArray.elementType;
	} else {
		return QualType.init;
	}
}

bool isArray (Expression e) {
	return (cast(ArrayType) peelAlias(e.type).type !is null);
}

bool isSlice (Expression e) {
	return (cast(SliceType) peelAlias(e.type).type !is null);
}

bool isPointer (Expression e) {
	return (cast(PointerType) peelAlias(e.type).type !is null);
}

bool isSliceOrArray (Expression e) {
	return (isSlice(e) || isArray(e));
}