internal static StringSegment ParseArguments(this StringSegment literal, out List <JsToken> arguments, char termination)
{
arguments = new List <JsToken>();
while (!literal.IsNullOrEmpty())
{
JsToken listValue;
literal = literal.AdvancePastWhitespace();
if (literal.GetChar(0) == termination)
{
literal = literal.Advance(1);
break;
}
if (literal.StartsWith("..."))
{
literal = literal.Advance(3);
literal = literal.ParseJsExpression(out listValue);
if (!(listValue is JsIdentifier) && !(listValue is JsArrayExpression))
{
throw new SyntaxErrorException($"Spread operator expected array but instead found {listValue.DebugToken()}");
}
listValue = new JsSpreadElement(listValue);
}
else
{
literal = literal.ParseJsExpression(out listValue);
}
arguments.Add(listValue);
literal = literal.AdvancePastWhitespace();
if (literal.IsNullOrEmpty())
{
break;
}
if (literal.GetChar(0) == termination)
{
literal = literal.Advance(1);
break;
}
literal = literal.AdvancePastWhitespace();
var c = literal.SafeGetChar(0);
if (c.IsEnd() || c == termination)
{
literal = literal.Advance(1);
break;
}
if (c != ',')
{
throw new SyntaxErrorException($"Unterminated arguments expression near: {literal.DebugLiteral()}");
}
literal = literal.Advance(1);
literal = literal.AdvancePastWhitespace();
}
literal = literal.AdvancePastWhitespace();
return(literal);
}
public static StringSegment ParseBinaryExpression(this StringSegment literal, out JsExpression expr, bool filterExpression)
{
literal = literal.AdvancePastWhitespace();
literal = literal.ParseJsToken(out var lhs, filterExpression: filterExpression);
if (literal.IsNullOrEmpty())
{
expr = lhs is JsExpression jsExpr
? jsExpr
: throw new SyntaxErrorException($"Expected Expression but was {lhs.DebugToken()}");
}
else
{
literal = literal.ParseJsBinaryOperator(out var op);
if (op == null)
{
throw new SyntaxErrorException($"Expected binary operator near: {literal.DebugLiteral()}");
}
var prec = JsTokenUtils.GetBinaryPrecedence(op.Token);
if (prec > 0)
{
literal = literal.ParseJsToken(out JsToken rhs, filterExpression: filterExpression);
var stack = new Stack <JsToken>();
stack.Push(lhs);
stack.Push(op);
stack.Push(rhs);
var precedences = new List <int> {
prec
};
while (true)
{
literal = literal.AdvancePastWhitespace();
if (filterExpression && literal.Length > 2 && (literal.GetChar(0) == '|' && literal.GetChar(1) != '|'))
{
break;
}
prec = literal.GetNextBinaryPrecedence();
if (prec == 0)
{
break;
}
while ((stack.Count > 2) && prec <= precedences[precedences.Count - 1])
{
rhs = stack.Pop();
var operand = (JsBinaryOperator)stack.Pop();
precedences.RemoveAt(precedences.Count - 1);
lhs = stack.Pop();
stack.Push(CreateJsExpression(lhs, operand, rhs));
}
literal = literal.ParseJsBinaryOperator(out op);
if (literal.IsNullOrEmpty())
{
throw new SyntaxErrorException($"Expected expression near: '{literal.DebugLiteral()}'");
}
literal = literal.ParseJsToken(out var token, filterExpression: filterExpression);
stack.Push(op);
stack.Push(token);
precedences.Add(prec);
}
var i = stack.Count - 1;
var ret = stack.Pop();
while (stack.Count > 0)
{
op = (JsBinaryOperator)stack.Pop();
lhs = stack.Pop();
ret = CreateJsExpression(lhs, op, ret);
}
expr = (JsExpression)ret;
}
else
{
expr = lhs is JsExpression jsExpr
? jsExpr
: throw new SyntaxErrorException($"Expected Expression but was {lhs.DebugToken()}");
}
}
return(literal);
}
internal static StringSegment ParseWhitespaceArgument(this StringSegment literal, out JsToken argument)
{
// replace everything after ':' up till new line and rewrite as single string to method
var endStringPos = literal.IndexOf("\n");
var endStatementPos = literal.IndexOf("}}");
if (endStringPos == -1 || (endStatementPos != -1 && endStatementPos < endStringPos))
{
endStringPos = endStatementPos;
}
if (endStringPos == -1)
{
throw new SyntaxErrorException($"Whitespace sensitive syntax did not find a '\\n' new line to mark the end of the statement, near {literal.DebugLiteral()}");
}
var originalArg = literal.Subsegment(0, endStringPos).Trim().ToString();
var rewrittenArgs = originalArg.Replace("{", "{{").Replace("}", "}}");
var strArg = new JsLiteral(rewrittenArgs);
argument = strArg;
return(literal.Subsegment(endStringPos));
}