| """ |
| HyperParser |
| =========== |
| This module defines the HyperParser class, which provides advanced parsing |
| abilities for the ParenMatch and other extensions. |
| The HyperParser uses PyParser. PyParser is intended mostly to give information |
| on the proper indentation of code. HyperParser gives some information on the |
| structure of code, used by extensions to help the user. |
| """ |
| |
| import string |
| import keyword |
| from idlelib import PyParse |
| |
| class HyperParser: |
| |
| def __init__(self, editwin, index): |
| """Initialize the HyperParser to analyze the surroundings of the given |
| index. |
| """ |
| |
| self.editwin = editwin |
| self.text = text = editwin.text |
| |
| parser = PyParse.Parser(editwin.indentwidth, editwin.tabwidth) |
| |
| def index2line(index): |
| return int(float(index)) |
| lno = index2line(text.index(index)) |
| |
| if not editwin.context_use_ps1: |
| for context in editwin.num_context_lines: |
| startat = max(lno - context, 1) |
| startatindex = repr(startat) + ".0" |
| stopatindex = "%d.end" % lno |
| # We add the newline because PyParse requires a newline at end. |
| # We add a space so that index won't be at end of line, so that |
| # its status will be the same as the char before it, if should. |
| parser.set_str(text.get(startatindex, stopatindex)+' \n') |
| bod = parser.find_good_parse_start( |
| editwin._build_char_in_string_func(startatindex)) |
| if bod is not None or startat == 1: |
| break |
| parser.set_lo(bod or 0) |
| else: |
| r = text.tag_prevrange("console", index) |
| if r: |
| startatindex = r[1] |
| else: |
| startatindex = "1.0" |
| stopatindex = "%d.end" % lno |
| # We add the newline because PyParse requires a newline at end. |
| # We add a space so that index won't be at end of line, so that |
| # its status will be the same as the char before it, if should. |
| parser.set_str(text.get(startatindex, stopatindex)+' \n') |
| parser.set_lo(0) |
| |
| # We want what the parser has, except for the last newline and space. |
| self.rawtext = parser.str[:-2] |
| # As far as I can see, parser.str preserves the statement we are in, |
| # so that stopatindex can be used to synchronize the string with the |
| # text box indices. |
| self.stopatindex = stopatindex |
| self.bracketing = parser.get_last_stmt_bracketing() |
| # find which pairs of bracketing are openers. These always correspond |
| # to a character of rawtext. |
| self.isopener = [i>0 and self.bracketing[i][1] > self.bracketing[i-1][1] |
| for i in range(len(self.bracketing))] |
| |
| self.set_index(index) |
| |
| def set_index(self, index): |
| """Set the index to which the functions relate. Note that it must be |
| in the same statement. |
| """ |
| indexinrawtext = \ |
| len(self.rawtext) - len(self.text.get(index, self.stopatindex)) |
| if indexinrawtext < 0: |
| raise ValueError("The index given is before the analyzed statement") |
| self.indexinrawtext = indexinrawtext |
| # find the rightmost bracket to which index belongs |
| self.indexbracket = 0 |
| while self.indexbracket < len(self.bracketing)-1 and \ |
| self.bracketing[self.indexbracket+1][0] < self.indexinrawtext: |
| self.indexbracket += 1 |
| if self.indexbracket < len(self.bracketing)-1 and \ |
| self.bracketing[self.indexbracket+1][0] == self.indexinrawtext and \ |
| not self.isopener[self.indexbracket+1]: |
| self.indexbracket += 1 |
| |
| def is_in_string(self): |
| """Is the index given to the HyperParser is in a string?""" |
| # The bracket to which we belong should be an opener. |
| # If it's an opener, it has to have a character. |
| return self.isopener[self.indexbracket] and \ |
| self.rawtext[self.bracketing[self.indexbracket][0]] in ('"', "'") |
| |
| def is_in_code(self): |
| """Is the index given to the HyperParser is in a normal code?""" |
| return not self.isopener[self.indexbracket] or \ |
| self.rawtext[self.bracketing[self.indexbracket][0]] not in \ |
| ('#', '"', "'") |
| |
| def get_surrounding_brackets(self, openers='([{', mustclose=False): |
| """If the index given to the HyperParser is surrounded by a bracket |
| defined in openers (or at least has one before it), return the |
| indices of the opening bracket and the closing bracket (or the |
| end of line, whichever comes first). |
| If it is not surrounded by brackets, or the end of line comes before |
| the closing bracket and mustclose is True, returns None. |
| """ |
| bracketinglevel = self.bracketing[self.indexbracket][1] |
| before = self.indexbracket |
| while not self.isopener[before] or \ |
| self.rawtext[self.bracketing[before][0]] not in openers or \ |
| self.bracketing[before][1] > bracketinglevel: |
| before -= 1 |
| if before < 0: |
| return None |
| bracketinglevel = min(bracketinglevel, self.bracketing[before][1]) |
| after = self.indexbracket + 1 |
| while after < len(self.bracketing) and \ |
| self.bracketing[after][1] >= bracketinglevel: |
| after += 1 |
| |
| beforeindex = self.text.index("%s-%dc" % |
| (self.stopatindex, len(self.rawtext)-self.bracketing[before][0])) |
| if after >= len(self.bracketing) or \ |
| self.bracketing[after][0] > len(self.rawtext): |
| if mustclose: |
| return None |
| afterindex = self.stopatindex |
| else: |
| # We are after a real char, so it is a ')' and we give the index |
| # before it. |
| afterindex = self.text.index("%s-%dc" % |
| (self.stopatindex, |
| len(self.rawtext)-(self.bracketing[after][0]-1))) |
| |
| return beforeindex, afterindex |
| |
| # This string includes all chars that may be in a white space |
| _whitespace_chars = " \t\n\\" |
| # This string includes all chars that may be in an identifier |
| _id_chars = string.ascii_letters + string.digits + "_" |
| # This string includes all chars that may be the first char of an identifier |
| _id_first_chars = string.ascii_letters + "_" |
| |
| # Given a string and pos, return the number of chars in the identifier |
| # which ends at pos, or 0 if there is no such one. Saved words are not |
| # identifiers. |
| def _eat_identifier(self, str, limit, pos): |
| i = pos |
| while i > limit and str[i-1] in self._id_chars: |
| i -= 1 |
| if i < pos and (str[i] not in self._id_first_chars or \ |
| keyword.iskeyword(str[i:pos])): |
| i = pos |
| return pos - i |
| |
| def get_expression(self): |
| """Return a string with the Python expression which ends at the given |
| index, which is empty if there is no real one. |
| """ |
| if not self.is_in_code(): |
| raise ValueError("get_expression should only be called if index "\ |
| "is inside a code.") |
| |
| rawtext = self.rawtext |
| bracketing = self.bracketing |
| |
| brck_index = self.indexbracket |
| brck_limit = bracketing[brck_index][0] |
| pos = self.indexinrawtext |
| |
| last_identifier_pos = pos |
| postdot_phase = True |
| |
| while 1: |
| # Eat whitespaces, comments, and if postdot_phase is False - one dot |
| while 1: |
| if pos>brck_limit and rawtext[pos-1] in self._whitespace_chars: |
| # Eat a whitespace |
| pos -= 1 |
| elif not postdot_phase and \ |
| pos > brck_limit and rawtext[pos-1] == '.': |
| # Eat a dot |
| pos -= 1 |
| postdot_phase = True |
| # The next line will fail if we are *inside* a comment, but we |
| # shouldn't be. |
| elif pos == brck_limit and brck_index > 0 and \ |
| rawtext[bracketing[brck_index-1][0]] == '#': |
| # Eat a comment |
| brck_index -= 2 |
| brck_limit = bracketing[brck_index][0] |
| pos = bracketing[brck_index+1][0] |
| else: |
| # If we didn't eat anything, quit. |
| break |
| |
| if not postdot_phase: |
| # We didn't find a dot, so the expression end at the last |
| # identifier pos. |
| break |
| |
| ret = self._eat_identifier(rawtext, brck_limit, pos) |
| if ret: |
| # There is an identifier to eat |
| pos = pos - ret |
| last_identifier_pos = pos |
| # Now, in order to continue the search, we must find a dot. |
| postdot_phase = False |
| # (the loop continues now) |
| |
| elif pos == brck_limit: |
| # We are at a bracketing limit. If it is a closing bracket, |
| # eat the bracket, otherwise, stop the search. |
| level = bracketing[brck_index][1] |
| while brck_index > 0 and bracketing[brck_index-1][1] > level: |
| brck_index -= 1 |
| if bracketing[brck_index][0] == brck_limit: |
| # We were not at the end of a closing bracket |
| break |
| pos = bracketing[brck_index][0] |
| brck_index -= 1 |
| brck_limit = bracketing[brck_index][0] |
| last_identifier_pos = pos |
| if rawtext[pos] in "([": |
| # [] and () may be used after an identifier, so we |
| # continue. postdot_phase is True, so we don't allow a dot. |
| pass |
| else: |
| # We can't continue after other types of brackets |
| if rawtext[pos] in "'\"": |
| # Scan a string prefix |
| while pos > 0 and rawtext[pos - 1] in "rRbBuU": |
| pos -= 1 |
| last_identifier_pos = pos |
| break |
| |
| else: |
| # We've found an operator or something. |
| break |
| |
| return rawtext[last_identifier_pos:self.indexinrawtext] |
