| 1 | """
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| 2 | HyperParser
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| 3 | ===========
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| 4 | This module defines the HyperParser class, which provides advanced parsing
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| 5 | abilities for the ParenMatch and other extensions.
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| 6 | The HyperParser uses PyParser. PyParser is intended mostly to give information
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| 7 | on the proper indentation of code. HyperParser gives some information on the
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| 8 | structure of code, used by extensions to help the user.
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| 9 | """
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| 10 |
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| 11 | import string
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| 12 | import keyword
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| 13 | from idlelib import PyParse
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| 14 |
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| 15 | class HyperParser:
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| 16 |
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| 17 | def __init__(self, editwin, index):
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| 18 | """Initialize the HyperParser to analyze the surroundings of the given
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| 19 | index.
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| 20 | """
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| 21 |
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| 22 | self.editwin = editwin
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| 23 | self.text = text = editwin.text
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| 24 |
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| 25 | parser = PyParse.Parser(editwin.indentwidth, editwin.tabwidth)
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| 26 |
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| 27 | def index2line(index):
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| 28 | return int(float(index))
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| 29 | lno = index2line(text.index(index))
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| 30 |
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| 31 | if not editwin.context_use_ps1:
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| 32 | for context in editwin.num_context_lines:
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| 33 | startat = max(lno - context, 1)
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| 34 | startatindex = repr(startat) + ".0"
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| 35 | stopatindex = "%d.end" % lno
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| 36 | # We add the newline because PyParse requires a newline at end.
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| 37 | # We add a space so that index won't be at end of line, so that
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| 38 | # its status will be the same as the char before it, if should.
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| 39 | parser.set_str(text.get(startatindex, stopatindex)+' \n')
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| 40 | bod = parser.find_good_parse_start(
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| 41 | editwin._build_char_in_string_func(startatindex))
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| 42 | if bod is not None or startat == 1:
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| 43 | break
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| 44 | parser.set_lo(bod or 0)
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| 45 | else:
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| 46 | r = text.tag_prevrange("console", index)
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| 47 | if r:
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| 48 | startatindex = r[1]
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| 49 | else:
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| 50 | startatindex = "1.0"
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| 51 | stopatindex = "%d.end" % lno
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| 52 | # We add the newline because PyParse requires a newline at end.
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| 53 | # We add a space so that index won't be at end of line, so that
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| 54 | # its status will be the same as the char before it, if should.
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| 55 | parser.set_str(text.get(startatindex, stopatindex)+' \n')
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| 56 | parser.set_lo(0)
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| 57 |
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| 58 | # We want what the parser has, except for the last newline and space.
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| 59 | self.rawtext = parser.str[:-2]
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| 60 | # As far as I can see, parser.str preserves the statement we are in,
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| 61 | # so that stopatindex can be used to synchronize the string with the
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| 62 | # text box indices.
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| 63 | self.stopatindex = stopatindex
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| 64 | self.bracketing = parser.get_last_stmt_bracketing()
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| 65 | # find which pairs of bracketing are openers. These always correspond
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| 66 | # to a character of rawtext.
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| 67 | self.isopener = [i>0 and self.bracketing[i][1] > self.bracketing[i-1][1]
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| 68 | for i in range(len(self.bracketing))]
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| 69 |
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| 70 | self.set_index(index)
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| 71 |
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| 72 | def set_index(self, index):
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| 73 | """Set the index to which the functions relate. Note that it must be
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| 74 | in the same statement.
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| 75 | """
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| 76 | indexinrawtext = \
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| 77 | len(self.rawtext) - len(self.text.get(index, self.stopatindex))
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| 78 | if indexinrawtext < 0:
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| 79 | raise ValueError("The index given is before the analyzed statement")
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| 80 | self.indexinrawtext = indexinrawtext
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| 81 | # find the rightmost bracket to which index belongs
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| 82 | self.indexbracket = 0
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| 83 | while self.indexbracket < len(self.bracketing)-1 and \
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| 84 | self.bracketing[self.indexbracket+1][0] < self.indexinrawtext:
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| 85 | self.indexbracket += 1
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| 86 | if self.indexbracket < len(self.bracketing)-1 and \
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| 87 | self.bracketing[self.indexbracket+1][0] == self.indexinrawtext and \
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| 88 | not self.isopener[self.indexbracket+1]:
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| 89 | self.indexbracket += 1
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| 90 |
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| 91 | def is_in_string(self):
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| 92 | """Is the index given to the HyperParser is in a string?"""
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| 93 | # The bracket to which we belong should be an opener.
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| 94 | # If it's an opener, it has to have a character.
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| 95 | return self.isopener[self.indexbracket] and \
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| 96 | self.rawtext[self.bracketing[self.indexbracket][0]] in ('"', "'")
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| 97 |
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| 98 | def is_in_code(self):
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| 99 | """Is the index given to the HyperParser is in a normal code?"""
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| 100 | return not self.isopener[self.indexbracket] or \
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| 101 | self.rawtext[self.bracketing[self.indexbracket][0]] not in \
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| 102 | ('#', '"', "'")
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| 103 |
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| 104 | def get_surrounding_brackets(self, openers='([{', mustclose=False):
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| 105 | """If the index given to the HyperParser is surrounded by a bracket
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| 106 | defined in openers (or at least has one before it), return the
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| 107 | indices of the opening bracket and the closing bracket (or the
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| 108 | end of line, whichever comes first).
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| 109 | If it is not surrounded by brackets, or the end of line comes before
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| 110 | the closing bracket and mustclose is True, returns None.
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| 111 | """
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| 112 | bracketinglevel = self.bracketing[self.indexbracket][1]
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| 113 | before = self.indexbracket
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| 114 | while not self.isopener[before] or \
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| 115 | self.rawtext[self.bracketing[before][0]] not in openers or \
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| 116 | self.bracketing[before][1] > bracketinglevel:
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| 117 | before -= 1
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| 118 | if before < 0:
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| 119 | return None
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| 120 | bracketinglevel = min(bracketinglevel, self.bracketing[before][1])
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| 121 | after = self.indexbracket + 1
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| 122 | while after < len(self.bracketing) and \
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| 123 | self.bracketing[after][1] >= bracketinglevel:
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| 124 | after += 1
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| 125 |
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| 126 | beforeindex = self.text.index("%s-%dc" %
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| 127 | (self.stopatindex, len(self.rawtext)-self.bracketing[before][0]))
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| 128 | if after >= len(self.bracketing) or \
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| 129 | self.bracketing[after][0] > len(self.rawtext):
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| 130 | if mustclose:
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| 131 | return None
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| 132 | afterindex = self.stopatindex
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| 133 | else:
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| 134 | # We are after a real char, so it is a ')' and we give the index
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| 135 | # before it.
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| 136 | afterindex = self.text.index("%s-%dc" %
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| 137 | (self.stopatindex,
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| 138 | len(self.rawtext)-(self.bracketing[after][0]-1)))
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| 139 |
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| 140 | return beforeindex, afterindex
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| 141 |
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| 142 | # This string includes all chars that may be in a white space
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| 143 | _whitespace_chars = " \t\n\\"
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| 144 | # This string includes all chars that may be in an identifier
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| 145 | _id_chars = string.ascii_letters + string.digits + "_"
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| 146 | # This string includes all chars that may be the first char of an identifier
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| 147 | _id_first_chars = string.ascii_letters + "_"
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| 148 |
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| 149 | # Given a string and pos, return the number of chars in the identifier
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| 150 | # which ends at pos, or 0 if there is no such one. Saved words are not
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| 151 | # identifiers.
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| 152 | def _eat_identifier(self, str, limit, pos):
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| 153 | i = pos
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| 154 | while i > limit and str[i-1] in self._id_chars:
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| 155 | i -= 1
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| 156 | if i < pos and (str[i] not in self._id_first_chars or \
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| 157 | keyword.iskeyword(str[i:pos])):
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| 158 | i = pos
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| 159 | return pos - i
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| 160 |
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| 161 | def get_expression(self):
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| 162 | """Return a string with the Python expression which ends at the given
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| 163 | index, which is empty if there is no real one.
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| 164 | """
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| 165 | if not self.is_in_code():
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| 166 | raise ValueError("get_expression should only be called if index "\
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| 167 | "is inside a code.")
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| 168 |
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| 169 | rawtext = self.rawtext
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| 170 | bracketing = self.bracketing
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| 171 |
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| 172 | brck_index = self.indexbracket
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| 173 | brck_limit = bracketing[brck_index][0]
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| 174 | pos = self.indexinrawtext
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| 175 |
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| 176 | last_identifier_pos = pos
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| 177 | postdot_phase = True
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| 178 |
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| 179 | while 1:
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| 180 | # Eat whitespaces, comments, and if postdot_phase is False - one dot
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| 181 | while 1:
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| 182 | if pos>brck_limit and rawtext[pos-1] in self._whitespace_chars:
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| 183 | # Eat a whitespace
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| 184 | pos -= 1
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| 185 | elif not postdot_phase and \
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| 186 | pos > brck_limit and rawtext[pos-1] == '.':
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| 187 | # Eat a dot
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| 188 | pos -= 1
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| 189 | postdot_phase = True
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| 190 | # The next line will fail if we are *inside* a comment, but we
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| 191 | # shouldn't be.
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| 192 | elif pos == brck_limit and brck_index > 0 and \
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| 193 | rawtext[bracketing[brck_index-1][0]] == '#':
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| 194 | # Eat a comment
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| 195 | brck_index -= 2
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| 196 | brck_limit = bracketing[brck_index][0]
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| 197 | pos = bracketing[brck_index+1][0]
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| 198 | else:
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| 199 | # If we didn't eat anything, quit.
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| 200 | break
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| 201 |
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| 202 | if not postdot_phase:
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| 203 | # We didn't find a dot, so the expression end at the last
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| 204 | # identifier pos.
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| 205 | break
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| 206 |
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| 207 | ret = self._eat_identifier(rawtext, brck_limit, pos)
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| 208 | if ret:
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| 209 | # There is an identifier to eat
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| 210 | pos = pos - ret
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| 211 | last_identifier_pos = pos
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| 212 | # Now, in order to continue the search, we must find a dot.
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| 213 | postdot_phase = False
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| 214 | # (the loop continues now)
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| 215 |
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| 216 | elif pos == brck_limit:
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| 217 | # We are at a bracketing limit. If it is a closing bracket,
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| 218 | # eat the bracket, otherwise, stop the search.
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| 219 | level = bracketing[brck_index][1]
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| 220 | while brck_index > 0 and bracketing[brck_index-1][1] > level:
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| 221 | brck_index -= 1
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| 222 | if bracketing[brck_index][0] == brck_limit:
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| 223 | # We were not at the end of a closing bracket
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| 224 | break
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| 225 | pos = bracketing[brck_index][0]
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| 226 | brck_index -= 1
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| 227 | brck_limit = bracketing[brck_index][0]
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| 228 | last_identifier_pos = pos
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| 229 | if rawtext[pos] in "([":
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| 230 | # [] and () may be used after an identifier, so we
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| 231 | # continue. postdot_phase is True, so we don't allow a dot.
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| 232 | pass
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| 233 | else:
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| 234 | # We can't continue after other types of brackets
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| 235 | if rawtext[pos] in "'\"":
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| 236 | # Scan a string prefix
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| 237 | while pos > 0 and rawtext[pos - 1] in "rRbBuU":
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| 238 | pos -= 1
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| 239 | last_identifier_pos = pos
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| 240 | break
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| 241 |
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| 242 | else:
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| 243 | # We've found an operator or something.
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| 244 | break
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| 245 |
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| 246 | return rawtext[last_identifier_pos:self.indexinrawtext]
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