| """Provide advanced parsing abilities for ParenMatch and other extensions. |
| |
| HyperParser uses PyParser. PyParser mostly gives information on the |
| proper indentation of code. HyperParser gives additional information on |
| the structure of code. |
| """ |
| from keyword import iskeyword |
| import string |
| |
| from idlelib import pyparse |
| |
| # all ASCII chars that may be in an identifier |
| _ASCII_ID_CHARS = frozenset(string.ascii_letters + string.digits + "_") |
| # all ASCII chars that may be the first char of an identifier |
| _ASCII_ID_FIRST_CHARS = frozenset(string.ascii_letters + "_") |
| |
| # lookup table for whether 7-bit ASCII chars are valid in a Python identifier |
| _IS_ASCII_ID_CHAR = [(chr(x) in _ASCII_ID_CHARS) for x in range(128)] |
| # lookup table for whether 7-bit ASCII chars are valid as the first |
| # char in a Python identifier |
| _IS_ASCII_ID_FIRST_CHAR = \ |
| [(chr(x) in _ASCII_ID_FIRST_CHARS) for x in range(128)] |
| |
| |
| class HyperParser: |
| def __init__(self, editwin, index): |
| "To initialize, 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_code(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 it. 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_code(text.get(startatindex, stopatindex)+' \n') |
| parser.set_lo(0) |
| |
| # We want what the parser has, minus the last newline and space. |
| self.rawtext = parser.code[:-2] |
| # Parser.code apparently 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. |
| |
| The index must be in the same statement. |
| """ |
| indexinrawtext = (len(self.rawtext) - |
| len(self.text.get(index, self.stopatindex))) |
| if indexinrawtext < 0: |
| raise ValueError("Index %s precedes the analyzed statement" |
| % index) |
| 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 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 in 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): |
| """Return bracket indexes or None. |
| |
| 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 |
| |
| # the set of built-in identifiers which are also keywords, |
| # i.e. keyword.iskeyword() returns True for them |
| _ID_KEYWORDS = frozenset({"True", "False", "None"}) |
| |
| @classmethod |
| def _eat_identifier(cls, str, limit, pos): |
| """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. |
| |
| This ignores non-identifier eywords are not identifiers. |
| """ |
| is_ascii_id_char = _IS_ASCII_ID_CHAR |
| |
| # Start at the end (pos) and work backwards. |
| i = pos |
| |
| # Go backwards as long as the characters are valid ASCII |
| # identifier characters. This is an optimization, since it |
| # is faster in the common case where most of the characters |
| # are ASCII. |
| while i > limit and ( |
| ord(str[i - 1]) < 128 and |
| is_ascii_id_char[ord(str[i - 1])] |
| ): |
| i -= 1 |
| |
| # If the above loop ended due to reaching a non-ASCII |
| # character, continue going backwards using the most generic |
| # test for whether a string contains only valid identifier |
| # characters. |
| if i > limit and ord(str[i - 1]) >= 128: |
| while i - 4 >= limit and ('a' + str[i - 4:pos]).isidentifier(): |
| i -= 4 |
| if i - 2 >= limit and ('a' + str[i - 2:pos]).isidentifier(): |
| i -= 2 |
| if i - 1 >= limit and ('a' + str[i - 1:pos]).isidentifier(): |
| i -= 1 |
| |
| # The identifier candidate starts here. If it isn't a valid |
| # identifier, don't eat anything. At this point that is only |
| # possible if the first character isn't a valid first |
| # character for an identifier. |
| if not str[i:pos].isidentifier(): |
| return 0 |
| elif i < pos: |
| # All characters in str[i:pos] are valid ASCII identifier |
| # characters, so it is enough to check that the first is |
| # valid as the first character of an identifier. |
| if not _IS_ASCII_ID_FIRST_CHAR[ord(str[i])]: |
| return 0 |
| |
| # All keywords are valid identifiers, but should not be |
| # considered identifiers here, except for True, False and None. |
| if i < pos and ( |
| iskeyword(str[i:pos]) and |
| str[i:pos] not in cls._ID_KEYWORDS |
| ): |
| return 0 |
| |
| return pos - i |
| |
| # This string includes all chars that may be in a white space |
| _whitespace_chars = " \t\n\\" |
| |
| 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 - a 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, 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] |
| |
| |
| if __name__ == '__main__': |
| from unittest import main |
| main('idlelib.idle_test.test_hyperparser', verbosity=2) |
