Commit 0eae829b authored by Dick Hollenbeck's avatar Dick Hollenbeck

factor out isNumber() in dsnlexer.cpp, add support for numbers with exponents,...

factor out isNumber() in dsnlexer.cpp, add support for numbers with exponents, leave commented out for further testing
parent 6231ce59
...@@ -394,6 +394,93 @@ static bool isSpace( int cc ) ...@@ -394,6 +394,93 @@ static bool isSpace( int cc )
} }
/**
* Function isNumber
* return true if the next sequence of s-expression text is a number:
* either an integer, fixed point, or float with exponent.
*
* @param cp is the start of the current token.
* @param limit is the end of the current line of text.
* @param next is where to put a pointer to the start of the token after this one, but is only
* updated if the return value is true.
* @return bool - true if this is a number, else false.
*/
static bool isNumber( const char* cp, const char* limit, const char** next )
{
#if 1 // no exponents supported
if( strchr( "+-.0123456789", *cp ) )
{
++cp;
while( cp<limit && strchr( ".0123456789", *cp ) )
++cp;
if( (cp<limit && isSpace(*cp)) || *cp==')' || *cp=='(' || cp==limit )
{
*next = cp;
return true;
}
}
return false;
#else // support numbers with exponents.
// regex for a float: "^[-+]?[0-9]*\\.?[0-9]+([eE][-+]?[0-9]+)?" i.e. any number
// is traversed, coded manually here:
bool sawNumber = false;
if( cp < limit && strchr( "-+", *cp ) )
++cp;
while( cp < limit && strchr( "0123456789", *cp ) )
{
++cp;
sawNumber = true;
}
{
if( cp < limit && *cp == '.' )
++cp;
while( cp < limit && strchr( "0123456789", *cp ) )
{
sawNumber = true;
++cp;
}
if( cp < limit && strchr( "Ee", *cp ) )
{
++cp;
sawNumber = false; // exponent mandates at least one digit thereafter.
if( cp < limit && strchr( "-+", *cp ) )
++cp;
while( cp < limit && strchr( "0123456789", *cp ) )
{
++cp;
sawNumber = true;
}
}
}
if( sawNumber )
{
if( ( cp<limit && isSpace(*cp) ) || *cp==')' || *cp=='(' || cp==limit )
{
*next = cp;
return true;
}
}
return false;
#endif
}
int DSNLEXER::NextTok() throw( IO_ERROR ) int DSNLEXER::NextTok() throw( IO_ERROR )
{ {
const char* cur = next; const char* cur = next;
...@@ -507,22 +594,13 @@ L_read: ...@@ -507,22 +594,13 @@ L_read:
goto exit; goto exit;
} }
// handle DSN_NUMBER if( isNumber( cur, limit, &head ) )
if( strchr( "+-.0123456789", *cur ) )
{ {
head = cur+1; // handle DSN_NUMBER
while( head<limit && strchr( ".0123456789", *head ) ) curText.clear();
++head; curText.append( cur, head );
curTok = DSN_NUMBER;
if( (head<limit && isSpace(*head)) || *head==')' || *head=='(' || head==limit ) goto exit;
{
curText.clear();
curText.append( cur, head );
curTok = DSN_NUMBER;
goto exit;
}
// else it was something like +5V, fall through below
} }
// a quoted string, will return DSN_STRING // a quoted string, will return DSN_STRING
......
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