public static IExpression Parse(JToken token, ExpressionParser parser)
{
if (token == null || !(token is JArray array))
{
throw new ArgumentException("");
}
var length = array.Count;
if (length != 2)
{
parser.Error("Expected one argument, but found " + length.ToString() + " instead.");
return(null);
}
var input = parser.Parse(array[1], 1);
if (input == null)
{
return(null);
}
if (!(input is MGLArrayType) && !(input is MGLStringType) && !(input is MGLValueType))
{
parser.Error("Expected argument of type string or array, but found " + input.GetType().ToString() + " instead.");
return(null);
}
return(new LengthExpression(input));
}
public static IExpression Parse(JToken token, ExpressionParser parser)
{
if (token == null || !(token is JArray array))
{
throw new ArgumentException("");
}
var length = array.Count;
if (length != 2 || !(array[1].Type == JTokenType.String))
{
parser.Error("'var' expression requires exactly one string literal argument.");
return(null);
}
string name = array[1].ToString();
var bindingValue = parser.Scope.GetBinding(name);
if (bindingValue == null)
{
parser.Error("Unknown variable " + name + ". Make sure " + name + " has been bound in an enclosing \"let\" expression before using it.", 1);
return(null);
}
return(new VarExpression(name, bindingValue));
}
public static IExpression Parse(JToken token, ExpressionParser parser)
{
if (token == null || !(token is JArray array))
{
throw new ArgumentException("");
}
var length = array.Count;
if (length < 4)
{
parser.Error("Expected at least 3 arguments, but found " + (length - 1).ToString() + " instead.");
return(null);
}
Dictionary <string, IExpression> bindings = new Dictionary <string, IExpression>();
for (var i = 1; i < length - 1; i += 2)
{
var name = array[i].ToString();
if (string.IsNullOrEmpty(name))
{
parser.Error("Expected string, but found " + array[i].GetType().ToString() + " instead.", i);
return(null);
}
bool isValidName = name.All(c => (c >= 48 && c <= 57 || c >= 65 && c <= 90 || c >= 97 && c <= 122 || c == '_'));
if (!isValidName)
{
parser.Error("Variable names must contain only alphanumeric characters or '_'.", 1);
return(null);
}
var bindingValue = parser.Parse(array[i + 1], null);
if (bindingValue == null)
{
return(null);
}
bindings.Add(name, bindingValue);
}
var result = parser.Parse(array[length - 1], length - 1, parser.Expected, bindings);
if (result == null)
{
return(null);
}
return(new LetExpression(bindings, result));
}
public static IExpression Parse(JArray array, ExpressionParser parser)
{
if (array == null)
{
throw new ArgumentException("");
}
var length = array.Count;
if (length != 3)
{
parser.Error($"Expected 2 arguments, but found {length - 1} instead.");
return(null);
}
var index = parser.Parse(array[1], 1, typeof(MGLNumberType));
var inputType = parser.Expected != null ? parser.Expected : typeof(MGLValueType);
var input = parser.Parse(array[2], 2, inputType);
if (index == null || input == null)
{
return(null);
}
return(new AtExpression(index, input));
}
