| import string |
| 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(string.join(map(str, stuff), " ") + "\n") |
| |
| # Find a def or class stmt. |
| |
| _defclassre = re.compile(r""" |
| ^ |
| [ \t]* |
| (?: |
| def [ \t]+ [a-zA-Z_]\w* [ \t]* \( |
| | class [ \t]+ [a-zA-Z_]\w* [ \t]* |
| (?: \( .* \) )? |
| [ \t]* : |
| ) |
| """, 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, but retaining |
| # enough info to determine the last non-ws char seen; if match is |
| # successful, and m.group(1) isn't None, m.end(1) less 1 is the |
| # index of the last non-ws char matched. |
| |
| _chew_ordinaryre = re.compile(r""" |
| (?: \s+ |
| | ( [^\s[\](){}#'"\\]+ ) |
| )+ |
| """, 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 = string.join(_tran, '') |
| del ch |
| |
| 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' |
| self.str = str |
| self.study_level = 0 |
| |
| # Return index of start of last (probable!) def or class stmt, or |
| # None if none found. It's only probable because we can't know |
| # whether we're in a string without reparsing from the start of |
| # the file -- and that's too slow in large files for routine use. |
| # |
| # 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_last_def_or_class(self, use_ps1, _defclassre=_defclassre): |
| str, pos = self.str, None |
| if use_ps1: |
| # hack for shell window |
| ps1 = '\n' + sys.ps1 |
| i = string.rfind(str, ps1) |
| if i >= 0: |
| pos = i + len(ps1) |
| self.str = str[:pos-1] + '\n' + str[pos:] |
| else: |
| i = 0 |
| while 1: |
| m = _defclassre(str, i) |
| if m: |
| pos, i = m.span() |
| else: |
| break |
| return pos |
| |
| # Throw away the start of the string. Intended to be called with |
| # find_last_def_or_class'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, _replace=string.replace, _find=string.find): |
| 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 = string.translate(str, _tran) |
| str = _replace(str, 'xxxxxxxx', 'x') |
| str = _replace(str, 'xxxx', 'x') |
| str = _replace(str, 'xx', 'x') |
| str = _replace(str, 'xx', 'x') |
| str = _replace(str, '\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 = _find(str, '\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, _rfind=string.rfind, _find=string.find, |
| _ws=string.whitespace): |
| 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 = _rfind(str, '\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: |
| i = m.end(1) - 1 # last non-ws (if any) |
| if i >= 0: |
| lastch = str[i] |
| p = m.end() |
| 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 = _find(str, '\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, _find=string.find): |
| self._study2() |
| assert self.continuation == C_BRACKET |
| j = self.lastopenbracketpos |
| str = self.str |
| n = len(str) |
| origi = i = string.rfind(str, '\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 = _find(str, '\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(string.expandtabs(str[i:j], |
| 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 = string.find(str, '\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(string.expandtabs(str[self.stmt_start : |
| i], |
| 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 |