private void Parse(string declaration)
{
StringTokenizer t = new StringTokenizer(declaration);
this.Parse(t);
}
private void ValidateExpression(string declaration)
{
StringTokenizer t = new StringTokenizer(declaration);
this.ValidateExpression(t);
}
private void ValidateExpression(StringTokenizer t)
{
this.Transforms = new List <Transform>();
this.Errors = new List <TokenError>();
this.VariableParameter = null;
this.VariableName = null;
Token token;
if (t.CurrentToken == null)
{
token = t.Next();
}
else
{
token = t.CurrentToken;
}
int startPos = token.Position;
// Ensure we are starting with a %
if (token.Kind != TokenKind.PercentSign)
{
this.Errors.Add(new TokenError("'%' expected", token.Line, token.Column, token.Value, this.context));
return;
}
token = t.Next();
// Make sure the second token is a word
if (token.Kind != TokenKind.Word)
{
this.Errors.Add(new TokenError("Expected variable name", token.Line, token.Column, token.Value, this.context));
return;
}
// Make sure the variable name we found actually exists
if (!VariableDeclaration.GetVariableNames().Contains(token.Value))
{
this.Errors.Add(new TokenError("Unknown variable", token.Line, token.Column, token.Value, this.context));
return;
}
else
{
this.VariableName = token.Value;
}
token = t.Next();
// We have reached the end of the declaration
if (token.Kind == TokenKind.PercentSign)
{
this.Declaration = t.Data.Substring(startPos, t.CurrentPosition - startPos);
return;
}
else if (token.Kind == TokenKind.Colon)
{
token = t.Next();
// Make sure we have a word for the variable parameter
if (token.Kind != TokenKind.Word)
{
this.Errors.Add(new TokenError("Expected variable parameter", token.Line, token.Column, token.Value, this.context));
return;
}
if (VariableDeclaration.DoesVariableSupportParameters(this.VariableName))
{
if (VariableDeclaration.IsValidParameter(this.VariableName, token.Value))
{
this.VariableParameter = token.Value;
}
else
{
this.Errors.Add(new TokenError(string.Format("Specified parameter was not valid for Variable '{0}'", this.VariableName), token.Line, token.Column, token.Value, this.context));
return;
}
}
else
{
this.Errors.Add(new TokenError(string.Format("Variable '{0}' does not support parameters", this.VariableName), token.Line, token.Column, token.Value, this.context));
return;
}
token = t.Next();
// Check to see if we have reached the end of the declaration
if (token.Kind == TokenKind.PercentSign)
{
this.Declaration = t.Data.Substring(startPos, t.CurrentPosition - startPos);
return;
}
}
if (token.Kind == TokenKind.TransformOperator)
{
TransformParser transformTokenizer = new TransformParser(t, TokenKind.PercentSign, this.context);
if (transformTokenizer.HasErrors)
{
foreach (TokenError error in transformTokenizer.Errors)
{
this.Errors.Add(error);
}
return;
}
else
{
this.Transforms = transformTokenizer.Transforms;
this.Declaration = t.Data.Substring(startPos, t.CurrentPosition - startPos);
return;
}
}
else
// We expect either an declaration end (%), a parameter operator (:), or a transform operator (>>)
{
this.Errors.Add(new TokenError("Expected '%', ':', '>>'", token.Line, token.Column, token.Value, this.context));
return;
}
}
public VariableDeclarationParser(StringTokenizer t, string context)
{
this.context = context;
this.ValidateExpression(t);
}