private IfStatement ParseIfElse ()
{
Token start = current;
Next ();
CheckSyntaxExpected (Token.Type.LeftParenthesis);
Token leftParen = current;
Next ();
Expression condition = ParseExpression ();
CheckSyntaxExpected (Token.Type.RightParenthesis);
Token rightParen = current;
Next ();
Statement ifBody = ParseStatement ();
Next ();
Statement elseBody = null;
TextPoint elsePoint = new TextPoint();
if (current.Kind == Token.Type.@else) {
elsePoint = new TextPoint(current.StartPosition);
elseBody = ParseStatement ();
}
return new IfStatement (condition, ifBody, elseBody, new TextSpan (start, current), new TextSpan (start, rightParen), new TextPoint (leftParen.StartPosition), new TextPoint (rightParen.StartPosition), elsePoint);
}
private LabelStatement ParseLabelStatement ()
{
Token start = current;
CheckSyntaxExpected (Token.Type.Identifier);
Identifier label = ((IdentifierToken)current).Spelling;
Next ();
CheckSyntaxExpected (Token.Type.Colon);
TextPoint colon = new TextPoint (current.StartPosition);
Next ();
if (LabelSet.Contains (label.Spelling))
Error (DiagnosticCode.EnclosingLabelShadowed, new TextSpan (start, current));
LabelSet.Add (label.Spelling);
Statement labeled = ParseStatement();
LabelSet.Remove (label.Spelling);
return new LabelStatement (label, labeled, new TextSpan (start, current), colon);
}
private List<Parameter> ParseListParametter ()
{
List<Parameter> result = new List<Parameter>();
if (current.Kind == Token.Type.RightParenthesis)
return result;
CheckSyntaxExpected (Token.Type.Identifier);
Next ();
TextPoint comma;
while (current.Kind == Token.Type.Comma) {
comma = new TextPoint (current.StartPosition);
Next ();
if (CheckSyntaxExpected (Token.Type.Identifier))
result.Add (new Parameter ((current as IdentifierToken).Spelling, new TextSpan (current, current), comma));
Next ();
}
return result;
}
private ArrayLiteralExpression ParseArrayLiteral ()
{
Token start = current;
List<ExpressionListElement> elements = new List<ExpressionListElement> ();
TextPoint comma = new TextPoint();
do {
Next ();
if (current.Kind == Token.Type.RightBracket)
break;
Expression exp = null;
//take care of elision
if (current.Kind != Token.Type.Comma)
exp = ParseAssignmentExpression (false);
ExpressionListElement element = new ExpressionListElement (exp, comma);
elements.Add (element);
comma = new TextPoint(current.StartPosition);
} while (current.Kind == Token.Type.Comma);
CheckSyntaxExpected (Token.Type.RightBracket);
return new ArrayLiteralExpression (elements, new TextSpan(start, current));
}
private Expression ParseObjectLiteral ()
{
Token start = current;
Next ();
List<ObjectLiteralElement> elements = new List<ObjectLiteralElement> ();
if (current.Kind == Token.Type.RightBrace) {
return new ObjectLiteralExpression (elements, new TextSpan (start, current));
}
ObjectLiteralElement element;
TextPoint comma = new TextPoint ();
TextPoint colon = new TextPoint ();
Expression name;
do {
switch (current.Kind) {
case Token.Type.Identifier:
name = new IdentifierExpression ((current as IdentifierToken).Spelling, new TextSpan (current, current));
break;
case Token.Type.NumericLiteral:
name = new NumericLiteralExpression (((NumericLiteralToken)current).Spelling, new TextSpan (current, current));
break;
case Token.Type.StringLiteral:
name = new StringLiteralExpression ((current as StringLiteralToken).Value, (current as StringLiteralToken).Spelling, new TextSpan (current, current));
break;
default:
Error (DiagnosticCode.SyntaxError, new TextSpan (current, current));
return new Expression (Expression.Operation.SyntaxError, new TextSpan (current, current));
}
Next ();
CheckSyntaxExpected (Token.Type.Colon);
colon = new TextPoint (current.StartPosition);
Next ();
Expression val = ParseAssignmentExpression (false);
element = new ObjectLiteralElement (name, val, colon, comma);
elements.Add (element);
comma = new TextPoint (current.StartPosition);
} while (current.Kind == Token.Type.Comma);
CheckSyntaxExpected (Token.Type.RightBrace);
elements.Add (element);
return new ObjectLiteralExpression (elements, new TextSpan (start, current));
}
private FunctionDefinition ParseFunctionDefinition ()
{
Token start = current;
Next ();
Identifier id = null;
if (CheckSyntaxExpected (Token.Type.Identifier))
id = ((IdentifierToken)current).Spelling;
TextPoint NameLocation = new TextPoint (current.StartPosition);
Next ();
TextPoint leftParenLocation = new TextPoint();
CheckSyntaxExpected (Token.Type.LeftParenthesis);
leftParenLocation = new TextPoint (current.StartPosition);
Next ();
List<Parameter> parametters = ParseListParametter ();
TextPoint rightParenLocation = new TextPoint();
CheckSyntaxExpected (Token.Type.RightParenthesis);
rightParenLocation = new TextPoint (current.StartPosition);
Token headerEnd = current;
Next ();
BlockStatement body = ParseBlock ();
TextSpan location = new TextSpan (start, current);
TextSpan HeaderLocation = new TextSpan (start, headerEnd);
return new FunctionDefinition (id, parametters, body, location, HeaderLocation, NameLocation, leftParenLocation, rightParenLocation);
}
