/// <summary>
/// Matches a <c>Index</c> non-terminal.
/// </summary>
/// <returns><c>true</c> if the <c>Index</c> was matched successfully; otherwise, <c>false</c>.</returns>
/// <remarks>
/// The non-terminal can start with: <c>Dot</c>, <c>OpenSquareBracket</c>.
/// </remarks>
protected virtual bool MatchIndex(ref Expression expression) {
LuatAstNodeBase index;
IToken indexToken;
int start = expression.StartOffset;
if (this.TokenIs(this.LookAheadToken, LuatTokenId.OpenSquareBracket)) {
if (!this.Match(LuatTokenId.OpenSquareBracket))
return false;
indexToken = this.Token;
Expression indexExpression = null;
if (!this.MatchExpression(out indexExpression))
return false;
index = indexExpression;
if (!this.Match(LuatTokenId.CloseSquareBracket))
return false;
expression.EndOffset = this.Token.EndOffset; // Expand to encompass ']'
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.Dot)) {
if (!this.Match(LuatTokenId.Dot))
return false;
indexToken = this.Token;
Identifier indexIdentifier = null;
if (!this.MatchIdentifier(out indexIdentifier)) {
this.RaiseError( this.Token.EndOffset - 1, "Expected identifier." );
}
index = indexIdentifier;
}
else
return false;
expression = new IndexExpression( expression, indexToken, index, new TextRange( start, this.Token.EndOffset ) );
return true;
}
/// <summary>
/// Matches a <c>FunctionName</c> non-terminal.
/// </summary>
/// <returns><c>true</c> if the <c>FunctionName</c> was matched successfully; otherwise, <c>false</c>.</returns>
/// <remarks>
/// The non-terminal can start with: <c>Identifier</c>.
/// </remarks>
protected virtual bool MatchFunctionName(out Expression expression, out bool expectsSelf) {
expression = null;
Identifier identifier;
IToken indexToken;
expectsSelf = false;
if (!this.MatchIdentifier(out identifier))
return false;
expression = new VariableExpression( identifier );
while (this.TokenIs(this.LookAheadToken, LuatTokenId.Dot)) {
if (!this.Match(LuatTokenId.Dot))
return false;
indexToken = this.Token;
if (!this.MatchIdentifier(out identifier))
return false;
expression = new IndexExpression( expression, indexToken, identifier );
}
if (this.TokenIs(this.LookAheadToken, LuatTokenId.Colon)) {
if (!this.Match(LuatTokenId.Colon))
return false;
indexToken = this.Token;
expectsSelf = true;
if (!this.MatchIdentifier(out identifier))
return false;
expression = new IndexExpression( expression, indexToken, identifier );
}
return true;
}