public static IEnumerable <Token <LexerTokenType> > LexTokens(Position start, ITextProvider textProvider)
{
System.Diagnostics.Debug.Assert(textProvider != null);
Position pos = start;
string text;
Range range;
// So that the caller's implementation of 'tryGetMoreText' doesn't have to buffer and be
// smart about token boundaries, we detect when we're about to yield the last token
// in the current buffer, and instead try to get more text and re-lex.
Token <LexerTokenType> lastToken = null;
while (textProvider.TryGetText(pos, out text, out range))
{
if (lastToken != null)
{
text = string.Concat(lastToken.Value, text);
range = new Range(lastToken.Range.Start, range.End);
}
foreach (Token <LexerTokenType> token in Lexer.LexTokens(text, range.Start))
{
if (token.Range.End.Offset != range.End.Offset)
{
lastToken = null;
yield return(token);
}
else
{
lastToken = token;
}
}
pos = range.End;
}
// If we fell off the end with a token, make sure the caller gets it!
if (lastToken != null)
{
yield return(lastToken);
}
}
public static IEnumerable <Statement <StatementType, ParserTokenType> > ParseStatements(Position start, ITextProvider textProvider)
{
TokenBuffer <LexerTokenType> tokenBuffer = new TokenBuffer <LexerTokenType>(Lexer.LexTokens(start, textProvider));
MsgsTokenInfo parserTokenInfo = new MsgsTokenInfo();
while (tokenBuffer.CurrentToken != null)
{
var statement = new StatementBuilder <StatementType, ParserTokenType, LexerTokenType>(tokenBuffer, parserTokenInfo);
bool readToEndOfLine = true;
switch (tokenBuffer.CurrentTokenType)
{
case LexerTokenType.Newline:
statement.As(StatementType.Ignorable, ParserTokenType.Whitespace);
// *Don't* ReadToEndOfLine(), because we've already read it!
readToEndOfLine = false;
break;
case LexerTokenType.Comment:
statement.As(StatementType.Ignorable, ParserTokenType.Comment);
break;
case LexerTokenType.TypeKeyword:
statement.As(StatementType.MessageTypeDefiniton, ParserTokenType.TypeKeyword)
.Expect(LexerTokenType.Whitespace, ParserTokenType.Whitespace)
.Expect(LexerTokenType.Identifier, ParserTokenType.MessageTypeDefinition)
.Expect(LexerTokenType.Whitespace, ParserTokenType.Whitespace)
.Expect(LexerTokenType.Number, ParserTokenType.MessageTypeRange)
.Expect(LexerTokenType.Whitespace, ParserTokenType.Whitespace)
.Expect(LexerTokenType.Number, ParserTokenType.MessageTypeRange);
break;
case LexerTokenType.Identifier:
// A leading identifier indicates a new message
statement.As(StatementType.Message, ParserTokenType.MessageType)
.Expect(LexerTokenType.Whitespace, ParserTokenType.Whitespace)
.Expect(LexerTokenType.Identifier, ParserTokenType.MessageName)
.Accept(LexerTokenType.Whitespace, ParserTokenType.Whitespace)
.Accept(LexerTokenType.Number, ParserTokenType.MessageTypeRange);
break;
case LexerTokenType.Whitespace:
// Whitespace is either a message instance, or blank or a comment... we have to look
// ahead to see what it is.
Token <LexerTokenType> firstToken;
tokenBuffer.Accept(LexerTokenType.Whitespace, out firstToken);
if (tokenBuffer.Is(LexerTokenType.Newline) || tokenBuffer.Is(LexerTokenType.Comment))
{
statement.As(StatementType.Ignorable, ParserTokenType.Whitespace, firstToken);
}
else
{
// Beginning of a message instance...
statement.As(StatementType.MessageInstance, ParserTokenType.Whitespace, firstToken);
// Loop through the remaining tokens on this line, interpreting the replacements and escapes...
while (tokenBuffer.CurrentToken != null &&
!tokenBuffer.Is(LexerTokenType.Newline) &&
!tokenBuffer.Is(LexerTokenType.Comment))
{
switch (tokenBuffer.CurrentTokenType)
{
default: // identifiers, numbers, etc. get treated as values
case LexerTokenType.Value:
statement.AcceptAny(ParserTokenType.Value);
break;
case LexerTokenType.Escape:
statement.Expect(LexerTokenType.Escape, ParserTokenType.Escape);
break;
case LexerTokenType.LeftBrace:
// parse the replacement format...
statement.Accept(LexerTokenType.LeftBrace, ParserTokenType.LeftBrace)
.Accept(LexerTokenType.LeftBracket, ParserTokenType.LeftBracket,
ifBracket =>
{
return(ifBracket.Accept(LexerTokenType.Identifier, ParserTokenType.ReplacementType,
ifType =>
{
return ifType.Accept(LexerTokenType.Comma, ParserTokenType.Comma,
ifComma => ifComma.Expect(LexerTokenType.Number, ParserTokenType.ReplacementPosition));
},
ifNoType =>
{
return ifNoType.Expect(LexerTokenType.Number, ParserTokenType.ReplacementPosition);
})
.Expect(LexerTokenType.RightBracket, ParserTokenType.RightBracket));
})
.Expect(LexerTokenType.Identifier, ParserTokenType.ReplacementName)
.Accept(LexerTokenType.Comma, ParserTokenType.Comma,
ifComma => ifComma.Expect(LexerTokenType.Number, ParserTokenType.ReplacementAlignment))
.Accept(LexerTokenType.Colon, ParserTokenType.Colon,
ifColon => ifColon.AggregateWhileNot(LexerTokenType.RightBrace, ParserTokenType.ReplacementFormat))
.Expect(LexerTokenType.RightBrace, ParserTokenType.RightBrace);
break;
case LexerTokenType.RightBrace: // needs to be escaped!
// Unknown, unexpected token!
// Note that we have to double the '}', because this is used in a string.Format call!
statement.Unexpected("Unescaped right-brace. This must be escaped (\\}}) for use in the message.");
break;
}
// We re-enable the statement so that we can keep consuming tokens...
statement.Enable();
}
}
break;
default:
// Unknown, unexpected token!
statement.As(StatementType.Unknown, ParserTokenType.Unknown);
break;
}
if (readToEndOfLine)
{
statement.ReadToEndOfLine(tokenBuffer);
}
yield return(statement.ToStatement());
}
}
