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Diffstat (limited to 'Tools/idle/PyParse.py')
| -rw-r--r-- | Tools/idle/PyParse.py | 584 |
1 files changed, 0 insertions, 584 deletions
diff --git a/Tools/idle/PyParse.py b/Tools/idle/PyParse.py deleted file mode 100644 index 422a86c..0000000 --- a/Tools/idle/PyParse.py +++ /dev/null @@ -1,584 +0,0 @@ -import re -import sys - -# Reason last stmt is continued (or C_NONE if it's not). -C_NONE, C_BACKSLASH, C_STRING, C_BRACKET = range(4) - -if 0: # for throwaway debugging output - def dump(*stuff): - sys.__stdout__.write(" ".join(map(str, stuff)) + "\n") - -# Find what looks like the start of a popular stmt. - -_synchre = re.compile(r""" - ^ - [ \t]* - (?: if - | for - | while - | else - | def - | return - | assert - | break - | class - | continue - | elif - | try - | except - | raise - | import - | yield - ) - \b -""", re.VERBOSE | re.MULTILINE).search - -# Match blank line or non-indenting comment line. - -_junkre = re.compile(r""" - [ \t]* - (?: \# \S .* )? - \n -""", re.VERBOSE).match - -# Match any flavor of string; the terminating quote is optional -# so that we're robust in the face of incomplete program text. - -_match_stringre = re.compile(r""" - \""" [^"\\]* (?: - (?: \\. | "(?!"") ) - [^"\\]* - )* - (?: \""" )? - -| " [^"\\\n]* (?: \\. [^"\\\n]* )* "? - -| ''' [^'\\]* (?: - (?: \\. | '(?!'') ) - [^'\\]* - )* - (?: ''' )? - -| ' [^'\\\n]* (?: \\. [^'\\\n]* )* '? -""", re.VERBOSE | re.DOTALL).match - -# Match a line that starts with something interesting; -# used to find the first item of a bracket structure. - -_itemre = re.compile(r""" - [ \t]* - [^\s#\\] # if we match, m.end()-1 is the interesting char -""", re.VERBOSE).match - -# Match start of stmts that should be followed by a dedent. - -_closere = re.compile(r""" - \s* - (?: return - | break - | continue - | raise - | pass - ) - \b -""", re.VERBOSE).match - -# Chew up non-special chars as quickly as possible. If match is -# successful, m.end() less 1 is the index of the last boring char -# matched. If match is unsuccessful, the string starts with an -# interesting char. - -_chew_ordinaryre = re.compile(r""" - [^[\](){}#'"\\]+ -""", re.VERBOSE).match - -# Build translation table to map uninteresting chars to "x", open -# brackets to "(", and close brackets to ")". - -_tran = ['x'] * 256 -for ch in "({[": - _tran[ord(ch)] = '(' -for ch in ")}]": - _tran[ord(ch)] = ')' -for ch in "\"'\\\n#": - _tran[ord(ch)] = ch -_tran = ''.join(_tran) -del ch - -try: - UnicodeType = type(unicode("")) -except NameError: - UnicodeType = None - -class Parser: - - def __init__(self, indentwidth, tabwidth): - self.indentwidth = indentwidth - self.tabwidth = tabwidth - - def set_str(self, str): - assert len(str) == 0 or str[-1] == '\n' - if type(str) is UnicodeType: - # The parse functions have no idea what to do with Unicode, so - # replace all Unicode characters with "x". This is "safe" - # so long as the only characters germane to parsing the structure - # of Python are 7-bit ASCII. It's *necessary* because Unicode - # strings don't have a .translate() method that supports - # deletechars. - uniphooey = str - str = [] - push = str.append - for raw in map(ord, uniphooey): - push(raw < 127 and chr(raw) or "x") - str = "".join(str) - self.str = str - self.study_level = 0 - - # Return index of a good place to begin parsing, as close to the - # end of the string as possible. This will be the start of some - # popular stmt like "if" or "def". Return None if none found: - # the caller should pass more prior context then, if possible, or - # if not (the entire program text up until the point of interest - # has already been tried) pass 0 to set_lo. - # - # This will be reliable iff given a reliable is_char_in_string - # function, meaning that when it says "no", it's absolutely - # guaranteed that the char is not in a string. - # - # Ack, hack: in the shell window this kills us, because there's - # no way to tell the differences between output, >>> etc and - # user input. Indeed, IDLE's first output line makes the rest - # look like it's in an unclosed paren!: - # Python 1.5.2 (#0, Apr 13 1999, ... - - def find_good_parse_start(self, use_ps1, is_char_in_string=None, - _synchre=_synchre): - str, pos = self.str, None - if use_ps1: - # shell window - ps1 = '\n' + sys.ps1 - i = str.rfind(ps1) - if i >= 0: - pos = i + len(ps1) - # make it look like there's a newline instead - # of ps1 at the start -- hacking here once avoids - # repeated hackery later - self.str = str[:pos-1] + '\n' + str[pos:] - return pos - - # File window -- real work. - if not is_char_in_string: - # no clue -- make the caller pass everything - return None - - # Peek back from the end for a good place to start, - # but don't try too often; pos will be left None, or - # bumped to a legitimate synch point. - limit = len(str) - for tries in range(5): - i = str.rfind(":\n", 0, limit) - if i < 0: - break - i = str.rfind('\n', 0, i) + 1 # start of colon line - m = _synchre(str, i, limit) - if m and not is_char_in_string(m.start()): - pos = m.start() - break - limit = i - if pos is None: - # Nothing looks like a block-opener, or stuff does - # but is_char_in_string keeps returning true; most likely - # we're in or near a giant string, the colorizer hasn't - # caught up enough to be helpful, or there simply *aren't* - # any interesting stmts. In any of these cases we're - # going to have to parse the whole thing to be sure, so - # give it one last try from the start, but stop wasting - # time here regardless of the outcome. - m = _synchre(str) - if m and not is_char_in_string(m.start()): - pos = m.start() - return pos - - # Peeking back worked; look forward until _synchre no longer - # matches. - i = pos + 1 - while 1: - m = _synchre(str, i) - if m: - s, i = m.span() - if not is_char_in_string(s): - pos = s - else: - break - return pos - - # Throw away the start of the string. Intended to be called with - # find_good_parse_start's result. - - def set_lo(self, lo): - assert lo == 0 or self.str[lo-1] == '\n' - if lo > 0: - self.str = self.str[lo:] - - # As quickly as humanly possible <wink>, find the line numbers (0- - # based) of the non-continuation lines. - # Creates self.{goodlines, continuation}. - - def _study1(self): - if self.study_level >= 1: - return - self.study_level = 1 - - # Map all uninteresting characters to "x", all open brackets - # to "(", all close brackets to ")", then collapse runs of - # uninteresting characters. This can cut the number of chars - # by a factor of 10-40, and so greatly speed the following loop. - str = self.str - str = str.translate(_tran) - str = str.replace('xxxxxxxx', 'x') - str = str.replace('xxxx', 'x') - str = str.replace('xx', 'x') - str = str.replace('xx', 'x') - str = str.replace('\nx', '\n') - # note that replacing x\n with \n would be incorrect, because - # x may be preceded by a backslash - - # March over the squashed version of the program, accumulating - # the line numbers of non-continued stmts, and determining - # whether & why the last stmt is a continuation. - continuation = C_NONE - level = lno = 0 # level is nesting level; lno is line number - self.goodlines = goodlines = [0] - push_good = goodlines.append - i, n = 0, len(str) - while i < n: - ch = str[i] - i = i+1 - - # cases are checked in decreasing order of frequency - if ch == 'x': - continue - - if ch == '\n': - lno = lno + 1 - if level == 0: - push_good(lno) - # else we're in an unclosed bracket structure - continue - - if ch == '(': - level = level + 1 - continue - - if ch == ')': - if level: - level = level - 1 - # else the program is invalid, but we can't complain - continue - - if ch == '"' or ch == "'": - # consume the string - quote = ch - if str[i-1:i+2] == quote * 3: - quote = quote * 3 - w = len(quote) - 1 - i = i+w - while i < n: - ch = str[i] - i = i+1 - - if ch == 'x': - continue - - if str[i-1:i+w] == quote: - i = i+w - break - - if ch == '\n': - lno = lno + 1 - if w == 0: - # unterminated single-quoted string - if level == 0: - push_good(lno) - break - continue - - if ch == '\\': - assert i < n - if str[i] == '\n': - lno = lno + 1 - i = i+1 - continue - - # else comment char or paren inside string - - else: - # didn't break out of the loop, so we're still - # inside a string - continuation = C_STRING - continue # with outer loop - - if ch == '#': - # consume the comment - i = str.find('\n', i) - assert i >= 0 - continue - - assert ch == '\\' - assert i < n - if str[i] == '\n': - lno = lno + 1 - if i+1 == n: - continuation = C_BACKSLASH - i = i+1 - - # The last stmt may be continued for all 3 reasons. - # String continuation takes precedence over bracket - # continuation, which beats backslash continuation. - if continuation != C_STRING and level > 0: - continuation = C_BRACKET - self.continuation = continuation - - # Push the final line number as a sentinel value, regardless of - # whether it's continued. - assert (continuation == C_NONE) == (goodlines[-1] == lno) - if goodlines[-1] != lno: - push_good(lno) - - def get_continuation_type(self): - self._study1() - return self.continuation - - # study1 was sufficient to determine the continuation status, - # but doing more requires looking at every character. study2 - # does this for the last interesting statement in the block. - # Creates: - # self.stmt_start, stmt_end - # slice indices of last interesting stmt - # self.lastch - # last non-whitespace character before optional trailing - # comment - # self.lastopenbracketpos - # if continuation is C_BRACKET, index of last open bracket - - def _study2(self): - if self.study_level >= 2: - return - self._study1() - self.study_level = 2 - - # Set p and q to slice indices of last interesting stmt. - str, goodlines = self.str, self.goodlines - i = len(goodlines) - 1 - p = len(str) # index of newest line - while i: - assert p - # p is the index of the stmt at line number goodlines[i]. - # Move p back to the stmt at line number goodlines[i-1]. - q = p - for nothing in range(goodlines[i-1], goodlines[i]): - # tricky: sets p to 0 if no preceding newline - p = str.rfind('\n', 0, p-1) + 1 - # The stmt str[p:q] isn't a continuation, but may be blank - # or a non-indenting comment line. - if _junkre(str, p): - i = i-1 - else: - break - if i == 0: - # nothing but junk! - assert p == 0 - q = p - self.stmt_start, self.stmt_end = p, q - - # Analyze this stmt, to find the last open bracket (if any) - # and last interesting character (if any). - lastch = "" - stack = [] # stack of open bracket indices - push_stack = stack.append - while p < q: - # suck up all except ()[]{}'"#\\ - m = _chew_ordinaryre(str, p, q) - if m: - # we skipped at least one boring char - newp = m.end() - # back up over totally boring whitespace - i = newp - 1 # index of last boring char - while i >= p and str[i] in " \t\n": - i = i-1 - if i >= p: - lastch = str[i] - p = newp - if p >= q: - break - - ch = str[p] - - if ch in "([{": - push_stack(p) - lastch = ch - p = p+1 - continue - - if ch in ")]}": - if stack: - del stack[-1] - lastch = ch - p = p+1 - continue - - if ch == '"' or ch == "'": - # consume string - # Note that study1 did this with a Python loop, but - # we use a regexp here; the reason is speed in both - # cases; the string may be huge, but study1 pre-squashed - # strings to a couple of characters per line. study1 - # also needed to keep track of newlines, and we don't - # have to. - lastch = ch - p = _match_stringre(str, p, q).end() - continue - - if ch == '#': - # consume comment and trailing newline - p = str.find('\n', p, q) + 1 - assert p > 0 - continue - - assert ch == '\\' - p = p+1 # beyond backslash - assert p < q - if str[p] != '\n': - # the program is invalid, but can't complain - lastch = ch + str[p] - p = p+1 # beyond escaped char - - # end while p < q: - - self.lastch = lastch - if stack: - self.lastopenbracketpos = stack[-1] - - # Assuming continuation is C_BRACKET, return the number - # of spaces the next line should be indented. - - def compute_bracket_indent(self): - self._study2() - assert self.continuation == C_BRACKET - j = self.lastopenbracketpos - str = self.str - n = len(str) - origi = i = str.rfind('\n', 0, j) + 1 - j = j+1 # one beyond open bracket - # find first list item; set i to start of its line - while j < n: - m = _itemre(str, j) - if m: - j = m.end() - 1 # index of first interesting char - extra = 0 - break - else: - # this line is junk; advance to next line - i = j = str.find('\n', j) + 1 - else: - # nothing interesting follows the bracket; - # reproduce the bracket line's indentation + a level - j = i = origi - while str[j] in " \t": - j = j+1 - extra = self.indentwidth - return len(str[i:j].expandtabs(self.tabwidth)) + extra - - # Return number of physical lines in last stmt (whether or not - # it's an interesting stmt! this is intended to be called when - # continuation is C_BACKSLASH). - - def get_num_lines_in_stmt(self): - self._study1() - goodlines = self.goodlines - return goodlines[-1] - goodlines[-2] - - # Assuming continuation is C_BACKSLASH, return the number of spaces - # the next line should be indented. Also assuming the new line is - # the first one following the initial line of the stmt. - - def compute_backslash_indent(self): - self._study2() - assert self.continuation == C_BACKSLASH - str = self.str - i = self.stmt_start - while str[i] in " \t": - i = i+1 - startpos = i - - # See whether the initial line starts an assignment stmt; i.e., - # look for an = operator - endpos = str.find('\n', startpos) + 1 - found = level = 0 - while i < endpos: - ch = str[i] - if ch in "([{": - level = level + 1 - i = i+1 - elif ch in ")]}": - if level: - level = level - 1 - i = i+1 - elif ch == '"' or ch == "'": - i = _match_stringre(str, i, endpos).end() - elif ch == '#': - break - elif level == 0 and ch == '=' and \ - (i == 0 or str[i-1] not in "=<>!") and \ - str[i+1] != '=': - found = 1 - break - else: - i = i+1 - - if found: - # found a legit =, but it may be the last interesting - # thing on the line - i = i+1 # move beyond the = - found = re.match(r"\s*\\", str[i:endpos]) is None - - if not found: - # oh well ... settle for moving beyond the first chunk - # of non-whitespace chars - i = startpos - while str[i] not in " \t\n": - i = i+1 - - return len(str[self.stmt_start:i].expandtabs(\ - self.tabwidth)) + 1 - - # Return the leading whitespace on the initial line of the last - # interesting stmt. - - def get_base_indent_string(self): - self._study2() - i, n = self.stmt_start, self.stmt_end - j = i - str = self.str - while j < n and str[j] in " \t": - j = j + 1 - return str[i:j] - - # Did the last interesting stmt open a block? - - def is_block_opener(self): - self._study2() - return self.lastch == ':' - - # Did the last interesting stmt close a block? - - def is_block_closer(self): - self._study2() - return _closere(self.str, self.stmt_start) is not None - - # index of last open bracket ({[, or None if none - lastopenbracketpos = None - - def get_last_open_bracket_pos(self): - self._study2() - return self.lastopenbracketpos |