|
Routines |
| Prev: 25AF | Up: Map | Next: 25E8 |
|
The address of this routine is derived from an offset found in the scanning function table.
This routine deals with string quotes, whether simple like "name" or more complex like "a ""white"" lie" or the seemingly redundant VAL$ """a""".
|
||||
| S_QUOTE | 25B3 | RST $18 | Fetch the current character. | |
| 25B4 | INC HL | Point to the start of the string. | ||
| 25B5 | PUSH HL | Save the start address. | ||
| 25B6 | LD BC,$0000 | Set the length to zero. | ||
| 25B9 | CALL S_QUOTE_S | Call the "matching" subroutine. | ||
| 25BC | JR NZ,S_Q_PRMS | Jump if zero reset - no more quotes. | ||
| S_Q_AGAIN | 25BE | CALL S_QUOTE_S | Call it again for a third quote. | |
| 25C1 | JR Z,S_Q_AGAIN | And again for the fifth, seventh etc. | ||
| 25C3 | CALL SYNTAX_Z | If testing syntax, jump to reset bit 6 of FLAGS and to continue scanning. | ||
| 25C6 | JR Z,S_Q_PRMS | |||
| 25C8 | RST $30 | Make space in the work space for the string and the terminating quote. | ||
| 25C9 | POP HL | Get the pointer to the start. | ||
| 25CA | PUSH DE | Save the pointer to the first space. | ||
| S_Q_COPY | 25CB | LD A,(HL) | Get a character from the string. | |
| 25CC | INC HL | Point to the next one. | ||
| 25CD | LD (DE),A | Copy last one to work space. | ||
| 25CE | INC DE | Point to the next space. | ||
| 25CF | CP "\"" | Is last character a '"'? | ||
| 25D1 | JR NZ,S_Q_COPY | If not, jump to copy next one. | ||
| 25D3 | LD A,(HL) | But if it was, do not copy next one; if next one is a '"', jump to copy the one after it; otherwise, finished with copying. | ||
| 25D4 | INC HL | |||
| 25D5 | CP "\"" | |||
| 25D7 | JR Z,S_Q_COPY | |||
| S_Q_PRMS | 25D9 | DEC BC | Get true length to BC. | |
|
Note that the first quote was not counted into the length; the final quote was, and is discarded now. Inside the string, the first, third, fifth, etc., quotes were counted in but the second, fourth, etc., were not.
|
||||
| 25DA | POP DE | Restore start of copied string. | ||
|
This entry point is used by the routine at S_SCREEN.
|
||||
| S_STRING | 25DB | LD HL,$5C3B | This is FLAGS; this entry point is used whenever bit 6 is to be reset and a string stacked if executing a line. This is done now. | |
| 25DE | RES 6,(HL) | |||
| 25E0 | BIT 7,(HL) | |||
| 25E2 | CALL NZ,STK_STO | |||
| 25E5 | JP S_CONT_2 | Jump to continue scanning the line. | ||
|
Note that in copying the string to the work space, every two pairs of string quotes inside the string ("") have been reduced to one pair of string quotes(").
|
||||
| Prev: 25AF | Up: Map | Next: 25E8 |