factor out isNumber() in dsnlexer.cpp, add support for numbers with exponents,... (0eae829b) · Commits · Elphel / kicad-source-mirror

common/dsnlexer.cpp

+93 −15

Original line number	Diff line number	Diff line
		@@ -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 )
		{
		const char* cur = next;
		@@ -507,24 +594,15 @@ L_read:
		goto exit;
		}

		// handle DSN_NUMBER
		if( strchr( "+-.0123456789", *cur ) )
		{
		head = cur+1;
		while( head<limit && strchr( ".0123456789", *head ) )
		++head;

		if( (head<limit && isSpace(head)) \|\| head==')' \|\| *head=='(' \|\| head==limit )
		if( isNumber( cur, limit, &head ) )
		{
		// handle DSN_NUMBER
		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
		if( *cur == stringDelimiter )
		{

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