func operatorKind(operator ast.TokenType) string {
switch {
case ast.IsMathOperator(operator):
return "math"
case ast.IsCompOperator(operator):
return "comparison"
case ast.IsLogicalOperator(operator):
return "logical"
}
// Actually, we shouldn't get here.. because this function is called only
// after the operator validation!
return "INVALID"
}
// getCostantNodeType - Given a ast.Node we want to know it's return type
// this method does exactly this, few examples:
// *) StringNode -> ast.TString
// *) UnaryNode -> we base the type by the node type
func getConstantNodeType(n ast.Node) ast.ValueType {
switch node := n.(type) {
case *ast.NumberNode:
if node.IsInt {
return ast.TInt
}
if node.IsFloat {
return ast.TFloat
}
case *ast.DurationNode:
return ast.TDuration
case *ast.StringNode:
return ast.TString
case *ast.BoolNode:
return ast.TBool
case *ast.RegexNode:
return ast.TRegex
case *ast.UnaryNode:
// If this is comparison operator we know for sure the output must be boolean
if node.Operator == ast.TokenNot {
return ast.TBool
}
// Could be float int or duration
if node.Operator == ast.TokenMinus {
return getConstantNodeType(node.Node)
}
case *ast.BinaryNode:
// Check first using only the operator
if ast.IsCompOperator(node.Operator) || ast.IsLogicalOperator(node.Operator) {
return ast.TBool
}
leftType := getConstantNodeType(node.Left)
rightType := getConstantNodeType(node.Right)
// Check known constant types
return binaryConstantTypes[operationKey{operator: node.Operator, leftType: leftType, rightType: rightType}]
case *ast.LambdaNode:
return getConstantNodeType(node.Expression)
}
return ast.InvalidType
}