/** \brief Read the next token from the string. */
ParserTokenReader::token_type ParserTokenReader::ReadNextToken()
{
assert(m_pParser);
std::stack<int> FunArgs;
const char_type *szFormula = m_strFormula.c_str();
token_type tok;
// Ignore all non printable characters when reading the expression
while (szFormula[m_iPos]>0 && szFormula[m_iPos]<=0x20)
++m_iPos;
if ( IsEOF(tok) ) return SaveBeforeReturn(tok); // Check for end of formula
if ( IsOprt(tok) ) return SaveBeforeReturn(tok); // Check for user defined binary operator
if ( IsFunTok(tok) ) return SaveBeforeReturn(tok); // Check for function token
if ( IsBuiltIn(tok) ) return SaveBeforeReturn(tok); // Check built in operators / tokens
if ( IsArgSep(tok) ) return SaveBeforeReturn(tok); // Check for function argument separators
if ( IsValTok(tok) ) return SaveBeforeReturn(tok); // Check for values / constant tokens
if ( IsVarTok(tok) ) return SaveBeforeReturn(tok); // Check for variable tokens
if ( IsStrVarTok(tok) ) return SaveBeforeReturn(tok); // Check for string variables
if ( IsString(tok) ) return SaveBeforeReturn(tok); // Check for String tokens
if ( IsInfixOpTok(tok) ) return SaveBeforeReturn(tok); // Check for unary operators
if ( IsPostOpTok(tok) ) return SaveBeforeReturn(tok); // Check for unary operators
// Check String for undefined variable token. Done only if a
// flag is set indicating to ignore undefined variables.
// This is a way to conditionally avoid an error if
// undefined variables occur.
// (The GetUsedVar function must suppress the error for
// undefined variables in order to collect all variable
// names including the undefined ones.)
if ( (m_bIgnoreUndefVar || m_pFactory) && IsUndefVarTok(tok) )
return SaveBeforeReturn(tok);
// Check for unknown token
//
// !!! From this point on there is no exit without an exception possible...
//
string_type strTok;
int iEnd = ExtractToken(m_pParser->ValidNameChars(), strTok, m_iPos);
if (iEnd!=m_iPos)
Error(ecUNASSIGNABLE_TOKEN, m_iPos, strTok);
Error(ecUNASSIGNABLE_TOKEN, m_iPos, m_strFormula.substr(m_iPos));
return token_type(); // never reached
}
/** \brief Read the next token from the string. */
ptr_tok_type TokenReader::ReadNextToken()
{
assert(m_pParser);
SkipCommentsAndWhitespaces();
int token_pos = m_nPos;
ptr_tok_type pTok;
// Check for end of expression
if (IsEOF(pTok))
return Store(pTok, token_pos);
if (IsNewline(pTok))
return Store(pTok, token_pos);
if (!(m_nSynFlags & noOPT) && IsOprt(pTok))
return Store(pTok, token_pos); // Check for user defined binary operator
if (!(m_nSynFlags & noIFX) && IsInfixOpTok(pTok))
return Store(pTok, token_pos); // Check for unary operators
if (IsValTok(pTok))
return Store(pTok, token_pos); // Check for values / constant tokens
if (IsBuiltIn(pTok))
return Store(pTok, token_pos); // Check built in operators / tokens
if (IsVarOrConstTok(pTok))
return Store(pTok, token_pos); // Check for variable tokens
if (IsFunTok(pTok))
return Store(pTok, token_pos);
if (!(m_nSynFlags & noPFX) && IsPostOpTok(pTok))
return Store(pTok, token_pos); // Check for unary operators
// 2.) We have found no token, maybe there is a token that we don't expect here.
// Again call the Identifier functions but this time only those we don't expect
// to find.
if ((m_nSynFlags & noOPT) && IsOprt(pTok))
return Store(pTok, token_pos); // Check for user defined binary operator
if ((m_nSynFlags & noIFX) && IsInfixOpTok(pTok))
return Store(pTok, token_pos); // Check for unary operators
if ((m_nSynFlags & noPFX) && IsPostOpTok(pTok))
return Store(pTok, token_pos); // Check for unary operators
// </ibg>
// Now we are in trouble because there is something completely unknown....
// Check the string for an undefined variable token. This is done
// only if a flag is set indicating to ignore undefined variables.
// This is a way to conditionally avoid an error if undefined variables
// occur. The GetExprVar function must supress the error for undefined
// variables in order to collect all variable names including the
// undefined ones.
if ((m_pParser->m_bIsQueryingExprVar || m_pParser->m_bAutoCreateVar) && IsUndefVarTok(pTok))
return Store(pTok, token_pos);
// Check for unknown token
//
// !!! From this point on there is no exit without an exception possible...
//
string_type sTok;
int iEnd = ExtractToken(m_pParser->ValidNameChars(), sTok, m_nPos);
ErrorContext err;
err.Errc = ecUNASSIGNABLE_TOKEN;
err.Expr = m_sExpr;
err.Pos = m_nPos;
if (iEnd != m_nPos)
err.Ident = sTok;
else
err.Ident = m_sExpr.substr(m_nPos);
throw ParserError(err);
}
