private void ParseReplacement(TokenReader <DocumentToken> reader, List <IDocumentExpression> ret)
{
var openToken = AdvanceAndExpectConstantType(reader, DocumentTokenType.BeginReplacementSegment);
var replacementKeyToken = AdvanceAndExpect(reader, DocumentTokenType.ReplacementKey, "replacement key", skipWhitespace: true);
List <DocumentToken> parameters = new List <DocumentToken>();
List <DocumentToken> body = new List <DocumentToken>();
while (reader.CanAdvance(skipWhitespace: true) && reader.Peek(skipWhitespace: true).TokenType == DocumentTokenType.ReplacementParameter)
{
var paramToken = reader.Advance(skipWhitespace: true);
parameters.Add(paramToken);
}
DocumentToken closeReplacementToken;
if (reader.TryAdvance(out closeReplacementToken, skipWhitespace: true) == false)
{
throw Unexpected(string.Format("'{0}' or '{1}'", DocumentToken.GetTokenTypeValue(DocumentTokenType.EndReplacementSegment), DocumentToken.GetTokenTypeValue(DocumentTokenType.QuickTerminateReplacementSegment)));
}
if (closeReplacementToken.TokenType == DocumentTokenType.EndReplacementSegment)
{
body.AddRange(ReadReplacementBody(reader, replacementKeyToken));
}
else if (closeReplacementToken.TokenType == DocumentTokenType.QuickTerminateReplacementSegment)
{
// do nothing, there is no body when the quick termination replacement segment is used
}
else
{
throw Unexpected(string.Format("'{0}' or '{1}'", DocumentToken.GetTokenTypeValue(DocumentTokenType.EndReplacementSegment), DocumentToken.GetTokenTypeValue(DocumentTokenType.QuickTerminateReplacementSegment)), closeReplacementToken);
}
IDocumentExpressionProvider provider;
if (this.expressionProviders.TryGetValue(replacementKeyToken.Value, out provider) == false)
{
provider = new EvalExpressionProvider();
}
var context = new DocumentExpressionContext
{
OpenToken = openToken,
CloseToken = closeReplacementToken,
Parameters = parameters.AsReadOnly(),
Body = body.AsReadOnly(),
ReplacementKeyToken = replacementKeyToken,
};
var expression = provider.CreateExpression(context);
ret.Add(expression);
}
private DocumentToken AdvanceAndExpectConstantType(TokenReader <DocumentToken> reader, DocumentTokenType expectedType)
{
DocumentToken read;
if (reader.TryAdvance(out read, skipWhitespace: true) == false)
{
throw Unexpected(DocumentToken.GetTokenTypeValue(expectedType));
}
if (read.TokenType != expectedType)
{
throw Unexpected(DocumentToken.GetTokenTypeValue(expectedType), read);
}
return(read);
}