private SObject ExecuteAssignment(ScriptStatement statement)
{
var exp = statement.Code;
var leftSide = "";
var rightSide = "";
var assignmentOperator = "";
// Get left and right side of the assignment:
{
var depth = 0;
var index = 0;
StringEscapeHelper escaper = new LeftToRightStringEscapeHelper(exp, 0);
while (index < exp.Length && assignmentOperator.Length == 0)
{
var t = exp[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == '(' || t == '[' || t == '{')
{
depth++;
}
else if (t == ')' || t == ']' || t == '}')
{
depth--;
}
else if (t == '=' && depth == 0)
{
var previous = ' ';
if (index > 0)
{
previous = exp[index - 1];
}
if (previous == '+' || previous == '-' || previous == '/' || previous == '*')
{
assignmentOperator = previous.ToString();
leftSide = exp.Substring(0, index - 1).TrimEnd();
}
else
{
assignmentOperator = "=";
leftSide = exp.Substring(0, index).TrimEnd();
}
rightSide = exp.Substring(index + 1).TrimStart();
}
}
index++;
}
}
// This means it's a function call, which cannot be assigned to:
if (leftSide.EndsWith(")") || leftSide.Length == 0)
{
return(ErrorHandler.ThrowError(ErrorType.ReferenceError, ErrorHandler.MessageReferenceInvalidAssignmentLeft));
}
var isIndexer = false;
var host = "";
var member = "";
if (leftSide.EndsWith("]"))
{
var indexerStartIndex = 0;
var index = leftSide.Length - 1;
var depth = 0;
StringEscapeHelper escaper = new RightToLeftStringEscapeHelper(leftSide, index);
while (index > 0 && !isIndexer)
{
var t = leftSide[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == '(' || t == '{')
{
depth--;
}
else if (t == ')' || t == ']' || t == '}')
{
depth++;
}
else if (t == '[')
{
depth--;
if (depth == 0 && index > 0)
{
isIndexer = true;
indexerStartIndex = index;
}
}
}
index--;
}
if (isIndexer)
{
member = leftSide.Substring(indexerStartIndex + 1);
member = member.Remove(member.Length - 1, 1);
host = leftSide.Remove(indexerStartIndex);
}
}
else
{
var foundMember = false;
if (leftSide.Contains("."))
{
var index = leftSide.Length - 1;
var depth = 0;
StringEscapeHelper escaper = new RightToLeftStringEscapeHelper(leftSide, index);
while (index > 0 && !foundMember)
{
var t = leftSide[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == '(' || t == '[' || t == '{')
{
depth--;
}
else if (t == ')' || t == ']' || t == '}')
{
depth++;
}
else if (t == '.' && depth == 0)
{
foundMember = true;
host = leftSide.Substring(0, index);
member = leftSide.Remove(0, index + 1);
}
}
index--;
}
}
if (!foundMember)
{
host = SObject.LiteralThis;
member = leftSide;
}
}
// When it's an indexer, we parse it as statement:
var accessor = isIndexer ? SObject.Unbox(ExecuteStatement(new ScriptStatement(member))) : CreateString(member);
var memberHost = ExecuteStatement(new ScriptStatement(host));
var value = SObject.Unbox(ExecuteStatement(new ScriptStatement(rightSide)));
if (assignmentOperator == "=")
{
memberHost.SetMember(this, accessor, isIndexer, value);
}
else
{
var memberContent = memberHost.GetMember(this, accessor, isIndexer);
var result = "";
switch (assignmentOperator)
{
case "+":
result = ObjectOperators.AddOperator(this, memberContent, value);
break;
case "-":
result = ObjectOperators.SubtractOperator(this, memberContent, value);
break;
case "*":
result = ObjectOperators.MultiplyOperator(this, memberContent, value);
break;
case "/":
result = ObjectOperators.DivideOperator(this, memberContent, value);
break;
}
memberHost.SetMember(this, accessor, isIndexer, ToScriptObject(result));
}
return(value);
}
/// <summary>
/// Captures an element left from the starting index.
/// </summary>
private static ElementCapture CaptureLeft(string exp, int index)
{
if (string.IsNullOrWhiteSpace(exp))
{
return new ElementCapture()
{
Length = 0, StartIndex = 0, Identifier = "", Depth = 0
}
}
;
var identifier = "";
var foundSeparatorChar = false;
var depth = 0;
StringEscapeHelper escaper = new RightToLeftStringEscapeHelper(exp, index);
while (index >= 0 && !foundSeparatorChar)
{
var t = exp[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == ')' || t == ']' || t == '}')
{
depth++;
}
else if (t == '(' || t == '[' || t == '{')
{
depth--;
}
}
if (depth < 0)
{
// this is when we walk out of the capture area because we are inside some area and a )]} appeared.
foundSeparatorChar = true;
}
else
{
if (!escaper.IsString && depth == 0)
{
if (t == '.')
{
// Check if the '.' is not a decimal separator:
if (!Regex.IsMatch(identifier.Trim(), RegexNumrightdot))
{
foundSeparatorChar = true;
}
}
else if (IdentifierSeparators.Contains(t))
{
foundSeparatorChar = true;
}
}
// Append the char to the identifier:
if (!foundSeparatorChar)
{
identifier = t + identifier;
}
}
index--;
}
// Check for a minus in front of the identifier to indicate a negative number:
if (index >= -1 && exp[index + 1] == '-' && !string.IsNullOrWhiteSpace(identifier))
{
identifier = "-" + identifier;
index--;
}
if (foundSeparatorChar)
{
return new ElementCapture()
{
StartIndex = index + 2, Length = identifier.Length, Identifier = identifier, Depth = depth
}
}
;
else
{
return new ElementCapture()
{
StartIndex = index + 1, Length = identifier.Length, Identifier = identifier, Depth = depth
}
};
}
private SObject InvokeMethod(SObject owner, string methodName)
{
var exp = methodName;
var index = exp.Length - 1;
var argumentStartIndex = -1;
var This = owner;
if (exp.EndsWith("()"))
{
argumentStartIndex = exp.Length - 2;
index = argumentStartIndex - 1;
}
else
{
var depth = 0;
var foundArguments = false;
StringEscapeHelper escaper = new RightToLeftStringEscapeHelper(exp, index);
while (index > 0 && !foundArguments)
{
var t = exp[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == ')' || t == '}' || t == ']')
{
depth++;
}
else if (t == '(' || t == '{' || t == '[')
{
depth--;
}
if (depth == 0)
{
if (index > 0)
{
foundArguments = true;
argumentStartIndex = index;
}
}
}
index--;
}
}
methodName = exp.Remove(argumentStartIndex);
var argumentCode = exp.Remove(0, argumentStartIndex + 1);
argumentCode = argumentCode.Remove(argumentCode.Length - 1, 1).Trim();
var parameters = ParseParameters(argumentCode);
if (methodName == CallLiteral && owner is SFunction)
{
This = Context.This;
}
// If it has an indexer, parse it again:
if (index > 0 && exp[index] == ']')
{
var member = InvokeMemberOrMethod(owner, methodName);
if ((member as SVariable)?.Data is SFunction)
{
return(owner.ExecuteMethod(this, ((SVariable)member).Identifier, owner, This, parameters));
}
else
{
return(ErrorHandler.ThrowError(ErrorType.TypeError, ErrorHandler.MessageTypeNotAFunction, methodName));
}
}
else
{
return(owner.ExecuteMethod(this, methodName, owner, This, parameters));
}
}
/// <summary>
/// Converts a string expression into a script object.
/// </summary>
private SObject ToScriptObject(string exp)
{
exp = exp.Trim();
// This means it's either an indexer or an array
if (exp.EndsWith("]"))
{
if (!(exp.StartsWith("[") && !exp.Remove(0, 1).Contains("["))) // When there's no "[" besides the start, and it starts with [, then it is an array. Otherwise, do real check.
{
// It is possible that we are having a simple array declaration here.
// We check that by looking if we can find a "[" before the expression ends:
var depth = 0;
var index = exp.Length - 2;
var indexerStartIndex = 0;
var foundIndexer = false;
StringEscapeHelper escaper = new RightToLeftStringEscapeHelper(exp, index);
while (index > 0 && !foundIndexer)
{
var t = exp[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == ')' || t == '}' || t == ']')
{
depth++;
}
else if (t == '(' || t == '{')
{
depth--;
}
else if (t == '[')
{
if (depth == 0)
{
if (index > 0)
{
indexerStartIndex = index;
foundIndexer = true;
}
}
else
{
depth--;
}
}
}
index--;
}
if (foundIndexer)
{
var indexerCode = exp.Substring(indexerStartIndex + 1, exp.Length - indexerStartIndex - 2);
var identifier = exp.Remove(indexerStartIndex);
var statementResult = ExecuteStatement(new ScriptStatement(indexerCode));
return(ToScriptObject(identifier).GetMember(this, statementResult, true));
}
}
}
// Normal object return procedure:
// Negative number:
var isNegative = false;
if (exp.StartsWith("-"))
{
exp = exp.Remove(0, 1);
isNegative = true;
}
SObject returnObject;
if (exp == SObject.LiteralNull)
{
returnObject = Null;
}
else if (exp == SObject.LiteralUndefined)
{
returnObject = Undefined;
}
else if (exp == SObject.LiteralBoolFalse)
{
returnObject = CreateBool(false);
}
else if (exp == SObject.LiteralBoolTrue)
{
returnObject = CreateBool(true);
}
else if (exp == SObject.LiteralNan)
{
returnObject = CreateNumber(double.NaN);
}
else if (exp == SObject.LiteralThis)
{
returnObject = Context.This;
}
else if (SNumber.TryParse(exp, out var dblResult))
{
returnObject = CreateNumber(dblResult);
}
else if (exp.StartsWith("\"") && exp.EndsWith("\"") || exp.StartsWith("\'") && exp.EndsWith("\'"))
{
returnObject = CreateString(exp.Remove(exp.Length - 1, 1).Remove(0, 1), true, false);
}
else if (exp.StartsWith("$\"") && exp.EndsWith("\"") || exp.StartsWith("$\'") && exp.EndsWith("\'"))
{
returnObject = CreateString(exp.Remove(exp.Length - 1, 1).Remove(0, 2), true, true);
}
else if (exp.StartsWith("@\"") && exp.EndsWith("\"") || exp.StartsWith("@\'") && exp.EndsWith("\'"))
{
returnObject = CreateString(exp.Remove(exp.Length - 1, 1).Remove(0, 2), false, false);
}
else if (exp.StartsWith("{") && exp.EndsWith("}"))
{
returnObject = SProtoObject.Parse(this, exp);
}
else if (exp.StartsWith("[") && exp.EndsWith("]"))
{
returnObject = SArray.Parse(this, exp);
}
else if (exp.StartsWith("function") && Regex.IsMatch(exp, RegexFunction))
{
returnObject = new SFunction(this, exp);
}
else if (Context.IsApiUsing(exp))
{
returnObject = Context.GetApiUsing(exp);
}
else if (Context.IsVariable(exp))
{
returnObject = Context.GetVariable(exp);
}
else if (Context.This.HasMember(this, exp))
{
returnObject = Context.This.GetMember(this, CreateString(exp), false);
}
else if (Context.IsPrototype(exp))
{
returnObject = Context.GetPrototype(exp);
}
else if (exp.StartsWith("new "))
{
returnObject = Context.CreateInstance(exp);
}
else if (exp.StartsWith(ObjectBuffer.ObjPrefix))
{
var strId = exp.Remove(0, ObjectBuffer.ObjPrefix.Length);
if (int.TryParse(strId, out var id) && ObjectBuffer.HasObject(id))
{
returnObject = (SObject)ObjectBuffer.GetObject(id);
}
else
{
returnObject = ErrorHandler.ThrowError(ErrorType.SyntaxError, ErrorHandler.MessageSyntaxInvalidToken, exp);
}
}
else
{
returnObject = ErrorHandler.ThrowError(ErrorType.ReferenceError, ErrorHandler.MessageReferenceNotDefined, exp);
}
if (isNegative)
{
returnObject = ObjectOperators.NegateNumber(this, returnObject);
}
return(returnObject);
}
private SObject InvokeMember(SObject owner, string memberName)
{
// When we have an indexer at the end of the member name, we get the member variable, then apply the indexer:
if (memberName.Last() == ']')
{
var exp = memberName;
var depth = 0;
var index = exp.Length - 2;
var indexerStartIndex = 0;
var foundIndexer = false;
var escaper = new RightToLeftStringEscapeHelper(exp, index);
while (index > 0 && !foundIndexer)
{
var t = exp[index];
escaper.CheckStartAt(index);
if (!escaper.IsString)
{
if (t == ')' || t == ']' || t == '}')
{
depth++;
}
else if (t == '(' || t == '{')
{
depth--;
}
else if (t == '[')
{
if (depth == 0)
{
if (index > 0)
{
indexerStartIndex = index;
foundIndexer = true;
}
}
else
{
depth--;
}
}
}
}
if (foundIndexer)
{
var indexerCode = exp.Substring(indexerStartIndex + 1, exp.Length - indexerStartIndex - 2);
var identifier = exp.Remove(indexerStartIndex);
var indexerObject = ExecuteStatement(new ScriptStatement(indexerCode));
return(InvokeMemberOrMethod(owner, identifier).GetMember(this, indexerObject, true));
}
else
{
return(ErrorHandler.ThrowError(ErrorType.SyntaxError, ErrorHandler.MessageSyntaxExpectedExpression, "end of string"));
}
}
else
{
return(owner.GetMember(this, CreateString(memberName), false));
}
}