private ScriptExpression ParseVariable()
{
Token currentToken = Current;
SourceSpan currentSpan = CurrentSpan;
SourceSpan endSpan = currentSpan;
string text = GetAsText(currentToken);
// Return ScriptLiteral for null, true, false
// Return ScriptAnonymousFunction
switch (text)
{
case "null":
ScriptLiteral nullValue = Open <ScriptLiteral>();
NextToken();
return(Close(nullValue));
case "true":
ScriptLiteral trueValue = Open <ScriptLiteral>();
trueValue.Value = true;
NextToken();
return(Close(trueValue));
case "false":
ScriptLiteral falseValue = Open <ScriptLiteral>();
falseValue.Value = false;
NextToken();
return(Close(falseValue));
case "do":
ScriptAnonymousFunction functionExp = Open <ScriptAnonymousFunction>();
functionExp.Function = ParseFunctionStatement(true);
ScriptAnonymousFunction func = Close(functionExp);
return(func);
case "this":
if (!_isLiquid)
{
ScriptThisExpression thisExp = Open <ScriptThisExpression>();
NextToken();
return(Close(thisExp));
}
break;
}
// Keeps trivia before this token
List <ScriptTrivia> triviasBefore = null;
if (_isKeepTrivia && _trivias.Count > 0)
{
triviasBefore = new List <ScriptTrivia>();
triviasBefore.AddRange(_trivias);
_trivias.Clear();
}
NextToken();
ScriptVariableScope scope = ScriptVariableScope.Global;
if (text.StartsWith("$"))
{
scope = ScriptVariableScope.Local;
text = text.Substring(1);
// Convert $0, $1... $n variable into $[0] $[1]...$[n] variables
int index;
if (int.TryParse(text, NumberStyles.Integer, CultureInfo.InvariantCulture, out index))
{
ScriptIndexerExpression indexerExpression = new ScriptIndexerExpression
{
Span = currentSpan,
Target = new ScriptVariableLocal(ScriptVariable.Arguments.Name)
{
Span = currentSpan
},
Index = new ScriptLiteral()
{
Span = currentSpan, Value = index
}
};
if (_isKeepTrivia)
{
if (triviasBefore != null)
{
indexerExpression.Target.AddTrivias(triviasBefore, true);
}
FlushTrivias(indexerExpression.Index, false);
}
return(indexerExpression);
}
}
else if (text == "for" || text == "while" || text == "tablerow" || (_isLiquid && (text == "forloop" || text == "tablerowloop")))
{
if (Current.Type == TokenType.Dot)
{
NextToken();
if (Current.Type == TokenType.Identifier)
{
endSpan = CurrentSpan;
string loopVariableText = GetAsText(Current);
NextToken();
scope = ScriptVariableScope.Loop;
if (_isLiquid)
{
switch (loopVariableText)
{
case "first":
text = ScriptVariable.LoopFirst.Name;
break;
case "last":
text = ScriptVariable.LoopLast.Name;
break;
case "index0":
text = ScriptVariable.LoopIndex.Name;
break;
case "rindex0":
text = ScriptVariable.LoopRIndex.Name;
break;
case "rindex":
case "index":
// Because forloop.index is 1 based index, we need to create a binary expression
// to support it here
bool isrindex = loopVariableText == "rindex";
ScriptNestedExpression nested = new ScriptNestedExpression()
{
Expression = new ScriptBinaryExpression()
{
Operator = ScriptBinaryOperator.Add,
Left = new ScriptVariableLoop(isrindex ? ScriptVariable.LoopRIndex.Name : ScriptVariable.LoopIndex.Name)
{
Span = currentSpan
},
Right = new ScriptLiteral(1)
{
Span = currentSpan
},
Span = currentSpan
},
Span = currentSpan
};
if (_isKeepTrivia)
{
if (triviasBefore != null)
{
nested.AddTrivias(triviasBefore, true);
}
FlushTrivias(nested, false);
}
return(nested);
case "length":
text = ScriptVariable.LoopLength.Name;
break;
case "col":
if (text != "tablerowloop")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, text + ".col"));
}
text = ScriptVariable.TableRowCol.Name;
break;
default:
text = text + "." + loopVariableText;
LogError(currentToken, string.Format(RS.InvalidLiquidLoopVariable, text));
break;
}
}
else
{
switch (loopVariableText)
{
case "first":
text = ScriptVariable.LoopFirst.Name;
break;
case "last":
if (text == "while")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, "while.last"));
}
text = ScriptVariable.LoopLast.Name;
break;
case "changed":
if (text == "while")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, "while.changed"));
}
text = ScriptVariable.LoopChanged.Name;
break;
case "length":
if (text == "while")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, "while.length"));
}
text = ScriptVariable.LoopLength.Name;
break;
case "even":
text = ScriptVariable.LoopEven.Name;
break;
case "odd":
text = ScriptVariable.LoopOdd.Name;
break;
case "index":
text = ScriptVariable.LoopIndex.Name;
break;
case "rindex":
if (text == "while")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, "while.rindex"));
}
text = ScriptVariable.LoopRIndex.Name;
break;
case "col":
if (text != "tablerow")
{
// unit test: 108-variable-loop-error2.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, text + ".col"));
}
text = ScriptVariable.TableRowCol.Name;
break;
default:
text = text + "." + loopVariableText;
// unit test: 108-variable-loop-error1.txt
LogError(currentToken, string.Format(RS.InvalidLoopVariable, text));
break;
}
}
// We no longer checks at parse time usage of loop variables, as they can be used in a wrap context
//if (!IsInLoop())
//{
// LogError(currentToken, string.Format(RS.InvalidLoopVariableOutsideLoop, text));
//}
}
else
{
LogError(currentToken, string.Format(RS.LoopVariableDotRequireIdentifier, Current.Type, text));
}
}
}
else if (_isLiquid && text == "continue")
{
scope = ScriptVariableScope.Local;
}
ScriptVariable result = ScriptVariable.Create(text, scope);
result.Span = new SourceSpan
{
FileName = currentSpan.FileName,
Start = currentSpan.Start,
End = endSpan.End
};
// A liquid variable can have `-` in its identifier
// If this is the case, we need to translate it to `this["this"]` instead
if (_isLiquid && text.IndexOf('-') >= 0)
{
ScriptIndexerExpression newExp = new ScriptIndexerExpression
{
Target = new ScriptThisExpression()
{
Span = result.Span
},
Index = new ScriptLiteral(text)
{
Span = result.Span
},
Span = result.Span
};
// Flush any trivias after
if (_isKeepTrivia)
{
if (triviasBefore != null)
{
newExp.Target.AddTrivias(triviasBefore, true);
}
FlushTrivias(newExp, false);
}
// Return the expression
return(newExp);
}
if (_isKeepTrivia)
{
// Flush any trivias after
if (triviasBefore != null)
{
result.AddTrivias(triviasBefore, true);
}
FlushTrivias(result, false);
}
return(result);
}