func (db *domBuilder) buildOptimizedBinaryOperatorExpression(node compilergraph.GraphNode, parentType typegraph.TypeReference, leftExpr codedom.Expression, rightExpr codedom.Expression) (codedom.Expression, bool) {
// Verify this is a supported native operator.
opString, hasOp := operatorMap[node.Kind()]
if !hasOp {
return nil, false
}
// Verify we have a native binary operator we can optimize.
if !parentType.IsNominal() {
return nil, false
}
isNumeric := false
switch {
case parentType.IsDirectReferenceTo(db.scopegraph.TypeGraph().IntType()):
isNumeric = true
case parentType.IsDirectReferenceTo(db.scopegraph.TypeGraph().BoolType()):
fallthrough
case parentType.IsDirectReferenceTo(db.scopegraph.TypeGraph().StringType()):
fallthrough
default:
return nil, false
}
// Handle the various kinds of operators.
switch node.Kind() {
case parser.NodeComparisonEqualsExpression:
fallthrough
case parser.NodeComparisonNotEqualsExpression:
// Always allowed.
break
case parser.NodeComparisonLTEExpression:
fallthrough
case parser.NodeComparisonLTExpression:
fallthrough
case parser.NodeComparisonGTEExpression:
fallthrough
case parser.NodeComparisonGTExpression:
// Only allowed for number.
if !isNumeric {
return nil, false
}
}
boolType := db.scopegraph.TypeGraph().BoolTypeReference()
unwrappedLeftExpr := codedom.NominalUnwrapping(leftExpr, parentType, node)
unwrappedRightExpr := codedom.NominalUnwrapping(rightExpr, parentType, node)
compareExpr := codedom.BinaryOperation(unwrappedLeftExpr, opString, unwrappedRightExpr, node)
return codedom.NominalRefWrapping(compareExpr,
boolType.NominalDataType(),
boolType,
node), true
}