private static ReadOnlySpan <char> ParseJsConditionalExpression(this ReadOnlySpan <char> literal, JsToken test, out JsConditionalExpression expression)
{
literal = literal.Advance(1);
literal = literal.ParseJsExpression(out var consequent);
literal = literal.AdvancePastWhitespace();
if (!literal.FirstCharEquals(':'))
{
throw new SyntaxErrorException($"Expected Conditional ':' but was {literal.DebugFirstChar()}");
}
literal = literal.Advance(1);
literal = literal.ParseJsExpression(out var alternate);
expression = new JsConditionalExpression(test, consequent, alternate);
return(literal);
}
public static ReadOnlySpan <char> ParseJsCallExpression(this ReadOnlySpan <char> literal, out JsCallExpression expression, bool filterExpression = false)
{
literal = literal.ParseIdentifier(out var token);
if (!(token is JsIdentifier identifier))
{
throw new SyntaxErrorException($"Expected identifier but instead found {token.DebugToken()}");
}
literal = literal.AdvancePastWhitespace();
if (literal.FirstCharEquals(WhitespaceArgument))
{
literal = literal.Advance(1);
literal = literal.ParseWhitespaceArgument(out var argument);
expression = new JsCallExpression(identifier, argument);
return(literal);
}
if (literal.StartsWith("=>"))
{
literal = literal.ParseArrowExpressionBody(new[] { new JsIdentifier("it") }, out var arrowExpr);
expression = new JsCallExpression(identifier, arrowExpr);
return(literal);
}
if (!literal.FirstCharEquals('('))
{
expression = new JsCallExpression(identifier);
return(literal);
}
literal = literal.Advance(1);
literal = literal.ParseArguments(out var args, termination: ')');
expression = new JsCallExpression(identifier, args.ToArray());
return(literal);
}
internal static ReadOnlySpan <char> ParseArguments(this ReadOnlySpan <char> literal, out List <JsToken> arguments, char termination)
{
arguments = new List <JsToken>();
while (!literal.IsNullOrEmpty())
{
JsToken listValue;
literal = literal.AdvancePastWhitespace();
if (literal[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($"Spread operator expected array but instead found {listValue.DebugToken()}");
}
listValue = new JsSpreadElement(listValue);
}
else
{
literal = literal.ParseJsExpression(out listValue);
}
arguments.Add(listValue);
literal = literal.AdvancePastWhitespace();
if (literal.IsNullOrEmpty())
{
break;
}
if (literal[0] == termination)
{
literal = literal.Advance(1);
break;
}
literal = literal.AdvancePastWhitespace();
var c = literal.SafeGetChar(0);
if (c.IsEnd() || c == termination)
{
literal = literal.Advance(1);
break;
}
if (c != ',')
{
throw new SyntaxErrorException($"Unterminated arguments expression near: {literal.DebugLiteral()}");
}
literal = literal.Advance(1);
literal = literal.AdvancePastWhitespace();
}
literal = literal.AdvancePastWhitespace();
return(literal);
}
public static ReadOnlySpan <char> ParseBinaryExpression(this ReadOnlySpan <char> 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 || op == JsAssignment.Operator)
{
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[0] == '|' && literal[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);
}
public static ReadOnlySpan <char> ParseJsExpression(this ReadOnlySpan <char> literal, out JsToken token, bool filterExpression)
{
var peekLiteral = literal.ParseJsToken(out var node, filterExpression: filterExpression);
peekLiteral = peekLiteral.AdvancePastWhitespace();
var peekChar = peekLiteral.SafeGetChar(0);
if (literal.IsNullOrEmpty() || peekChar.IsExpressionTerminatorChar())
{
token = node;
return(peekLiteral);
}
if (peekChar == ConditionalExpressionTestChar &&
peekLiteral.SafeGetChar(1) != ConditionalExpressionTestChar) // not ??
{
literal = peekLiteral.ParseJsConditionalExpression(node, out var expression);
token = expression;
return(literal);
}
if (node is JsIdentifier identifier)
{
if (peekLiteral.StartsWith("=>"))
{
literal = peekLiteral.ParseArrowExpressionBody(new[] { identifier }, out var arrowExpr);
token = arrowExpr;
return(literal);
}
var kind = identifier.Name == "var"
? JsVariableDeclarationKind.Var
: identifier.Name == "let"
? JsVariableDeclarationKind.Let
: identifier.Name == "const"
? JsVariableDeclarationKind.Const
: (JsVariableDeclarationKind?)null;
if (kind != null)
{
literal = peekLiteral.ParseVariableDeclaration(kind.Value, out var varDec);
token = varDec;
return(literal);
}
if (peekChar == '=' && peekLiteral.SafeGetChar(1) != '=') // not ==, ===
{
literal = peekLiteral.ParseAssignmentExpression(identifier, out var assignExpr);
token = assignExpr;
return(literal);
}
}
peekLiteral = peekLiteral.AdvancePastWhitespace();
if (!peekLiteral.IsNullOrEmpty())
{
if (filterExpression && peekLiteral.Length > 2)
{
var char1 = peekLiteral[0];
var char2 = peekLiteral[1];
if ((char1 == '|' && char2 != '|') || (char1 == '}' && char2 == '}'))
{
token = node;
return(peekLiteral);
}
}
}
peekLiteral = peekLiteral.ParseJsBinaryOperator(out var op);
if (op != null)
{
literal = literal.ParseBinaryExpression(out var expr, filterExpression);
token = expr;
literal = literal.AdvancePastWhitespace();
if (literal.FirstCharEquals(ConditionalExpressionTestChar))
{
literal = literal.ParseJsConditionalExpression(expr, out var conditionalExpr);
token = conditionalExpr;
return(literal);
}
return(literal);
}
literal = peekLiteral.ParseJsMemberExpression(ref node, filterExpression);
token = node;
return(literal);
}
public static ReadOnlySpan <char> ParseJsExpression(this ReadOnlySpan <char> literal, out JsToken token, bool filterExpression)
{
var peekLiteral = literal.ParseJsToken(out var node, filterExpression: filterExpression);
peekLiteral = peekLiteral.AdvancePastWhitespace();
var peekChar = peekLiteral.SafeGetChar(0);
if (literal.IsNullOrEmpty() || peekChar.IsExpressionTerminatorChar())
{
token = node;
return(peekLiteral);
}
if (peekChar == ConditionalExpressionTestChar &&
peekLiteral.SafeGetChar(1) != ConditionalExpressionTestChar) // not ??
{
literal = peekLiteral.ParseJsConditionalExpression(node, out var expression);
token = expression;
return(literal);
}
if (node is JsIdentifier identifier && peekLiteral.StartsWith("=>"))
{
literal = peekLiteral.ParseArrowExpressionBody(new[] { identifier }, out var arrowExpr);
token = arrowExpr;
return(literal);
}
peekLiteral = peekLiteral.AdvancePastWhitespace();
if (!peekLiteral.IsNullOrEmpty())
{
if (filterExpression && peekLiteral.Length > 2)
{
var char1 = peekLiteral[0];
var char2 = peekLiteral[1];
if ((char1 == '|' && char2 != '|') || (char1 == '}' && char2 == '}'))
{
token = node;
return(peekLiteral);
}
}
}
peekLiteral = peekLiteral.ParseJsBinaryOperator(out var op);
if (op != null)
{
literal = literal.ParseBinaryExpression(out var expr, filterExpression);
token = expr;
literal = literal.AdvancePastWhitespace();
if (literal.FirstCharEquals(ConditionalExpressionTestChar))
{
literal = literal.ParseJsConditionalExpression(expr, out var conditionalExpr);
token = conditionalExpr;
return(literal);
}
return(literal);
}
literal = peekLiteral.ParseJsMemberExpression(ref node, filterExpression);
token = node;
return(literal);
}
