Better debugging, but still no progress on what's up.
Cat's Eye Technologies
11 years ago
| 5 | 5 | |
| 6 | 6 | DEBUG = False |
| 7 | 7 | |
| 8 | def enc(x): | |
| 9 | if not isinstance(x, str): | |
| 10 | x = unicode(x) | |
| 11 | return x.encode('ascii', 'xmlcharrefreplace') | |
| 12 | ||
| 8 | 13 | def debug(x): |
| 9 | 14 | if DEBUG: |
| 10 | print x.encode('ascii', 'xmlcharrefreplace') | |
| 15 | print enc(x) | |
| 11 | 16 | |
| 12 | 17 | |
| 13 | 18 | class TamsinParseError(ValueError): |
| 73 | 78 | debug("setting buffer to '%s'" % buffer) |
| 74 | 79 | self.buffer = buffer |
| 75 | 80 | self.position = 0 |
| 81 | self.reset_position = None | |
| 76 | 82 | self.token = None |
| 77 | 83 | self.scan() |
| 78 | 84 | |
| 96 | 102 | def isalnum(self): |
| 97 | 103 | return self.buffer[self.position].isalnum() |
| 98 | 104 | |
| 105 | def report_buffer(self, position, length): | |
| 106 | """Display a printable snippet of the buffer, of maximum | |
| 107 | length length, starting at position. | |
| 108 | ||
| 109 | """ | |
| 110 | report = self.buffer[position:position+length] | |
| 111 | if len(report) == length: | |
| 112 | report += '...' | |
| 113 | return enc(report) | |
| 114 | ||
| 99 | 115 | def error(self, expected): |
| 100 | report = self.buffer[self.position:self.position+20] | |
| 101 | if len(report) == 20: | |
| 102 | report += '...' | |
| 103 | raise ValueError(u"Expected %s, found '%s' at '%s...'" % | |
| 104 | (expected.encode('ascii', 'xmlcharrefreplace'), | |
| 105 | self.token.encode('ascii', 'xmlcharrefreplace'), | |
| 106 | report.encode('ascii', 'xmlcharrefreplace'))) | |
| 116 | raise ValueError(u"Expected %s, found '%s' at '%s...' (position %s)" % | |
| 117 | (enc(expected), | |
| 118 | enc(self.token), | |
| 119 | self.report_buffer(self.position, 20), | |
| 120 | self.position)) | |
| 107 | 121 | |
| 108 | 122 | def clone(self, class_=None): |
| 109 | 123 | if class_ is None: |
| 119 | 133 | debug("scanned: '%s'" % self.token) |
| 120 | 134 | |
| 121 | 135 | def switch(self, class_): |
| 136 | """Note that there is a different method for switching back to | |
| 137 | a scanner you just switched from! (TODO: Python's with?) | |
| 138 | ||
| 139 | """ | |
| 122 | 140 | # 'putback' the token |
| 123 | debug("reset position %s, position %s, putbacking '%s'" % | |
| 141 | debug("scanner.switch(). reset position %s, position %s, putbacking '%s'" % | |
| 124 | 142 | (self.reset_position, self.position, |
| 125 | 143 | self.buffer[self.reset_position:self.position-self.reset_position+1]) |
| 126 | 144 | ) |
| 130 | 148 | new_scanner.scan() |
| 131 | 149 | return new_scanner |
| 132 | 150 | |
| 151 | def switch_back(self, class_): | |
| 152 | debug("scanner.switch_back(). reset position %s, position %s, putbacking '%s'" % | |
| 153 | (self.reset_position, self.position, | |
| 154 | self.buffer[self.reset_position:self.position-self.reset_position+1]) | |
| 155 | ) | |
| 156 | self.position = self.reset_position | |
| 157 | self.token = None | |
| 158 | new_scanner = self.clone(class_=class_) | |
| 159 | #new_scanner.scan() | |
| 160 | return new_scanner | |
| 161 | ||
| 133 | 162 | def consume(self, t): |
| 134 | 163 | #print repr(self.token), repr(t) |
| 135 | 164 | if self.token == t: |
| 143 | 172 | if r is None: |
| 144 | 173 | self.error("'%s'" % t) |
| 145 | 174 | return r |
| 175 | ||
| 176 | def dump(self): | |
| 177 | if DEBUG: | |
| 178 | print "--%r" % self | |
| 179 | print " buffer: %s" % enc(self.buffer) | |
| 180 | print " position: %s" % self.position | |
| 181 | print " buffer at position: %s" % self.report_buffer(self.position, 40) | |
| 182 | print " reset_position: %s" % self.reset_position | |
| 183 | print " buffer at reset_pos: %s" % self.report_buffer(self.reset_position, 40) | |
| 184 | print " token: %s" % enc(self.token) | |
| 146 | 185 | |
| 147 | 186 | |
| 148 | 187 | class TamsinScanner(Scanner): |
| 558 | 597 | self.production = prods[0] |
| 559 | 598 | ProductionScanner.__init__(self, buffer) |
| 560 | 599 | new_scanner_class = CustomScanner |
| 600 | debug("SWITCHING SCANNERS") | |
| 561 | 601 | old_scanner_class = self.scanner.__class__ |
| 562 | 602 | old_scanner = self.scanner |
| 563 | 603 | self.scanner = self.scanner.switch(new_scanner_class) |
| 564 | 604 | debug("SWITCHED SCANNER FROM %r TO %r" % |
| 565 | 605 | (old_scanner, self.scanner)) |
| 606 | old_scanner.dump() | |
| 607 | self.scanner.dump() | |
| 566 | 608 | result = self.interpret(sub) |
| 567 | 609 | old_scanner = self.scanner |
| 568 | 610 | self.scanner = self.scanner.switch(old_scanner_class) |
| 569 | 611 | debug("SWITCHED SCANNER BACK TO %r FROM %r" % |
| 570 | 612 | (self.scanner, old_scanner)) |
| 613 | old_scanner.dump() | |
| 614 | self.scanner.dump() | |
| 571 | 615 | return result |
| 572 | 616 | elif ast[0] == 'WHILE': |
| 573 | 617 | result = Term('nil') |