| 1 | """expr_parse.py."""
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| 2 | from __future__ import print_function
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| 3 |
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| 4 | from _devbuild.gen.syntax_asdl import (loc, Token, DoubleQuoted, SingleQuoted,
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| 5 | CommandSub, ShArrayLiteral,
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| 6 | CompoundWord, word_part_t, word_e)
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| 7 | from _devbuild.gen.id_kind_asdl import Id, Kind, Id_str
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| 8 | from _devbuild.gen.types_asdl import lex_mode_e
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| 9 |
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| 10 | from display import ui
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| 11 | from core.error import p_die
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| 12 | from frontend import consts
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| 13 | from frontend import lexer
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| 14 | from frontend import reader
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| 15 | from mycpp import mylib
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| 16 | from mycpp.mylib import log, tagswitch
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| 17 | from osh import braces
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| 18 | from osh import word_
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| 19 | from osh import word_compile
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| 20 | from pgen2 import parse
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| 21 | from pgen2.pnode import PNodeAllocator
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| 22 |
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| 23 | _ = log
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| 24 |
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| 25 | from typing import TYPE_CHECKING, Any, Dict, Tuple, List, cast, Optional
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| 26 | if TYPE_CHECKING:
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| 27 | from frontend.lexer import Lexer
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| 28 | from frontend.parse_lib import ParseContext
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| 29 | from pgen2.grammar import Grammar
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| 30 | from pgen2.pnode import PNode
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| 31 |
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| 32 | if mylib.PYTHON:
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| 33 |
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| 34 | class ParseTreePrinter(object):
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| 35 | """Prints a tree of PNode instances."""
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| 36 |
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| 37 | def __init__(self, names):
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| 38 | # type: (Dict[int, str]) -> None
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| 39 | self.names = names
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| 40 | self.f = mylib.Stdout()
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| 41 |
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| 42 | def _Print(self, pnode, indent, i):
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| 43 | # type: (PNode, int, int) -> None
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| 44 |
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| 45 | ind = ' ' * indent
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| 46 | # NOTE:
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| 47 | # - why isn't 'tok' None for PRODUCTIONS? There is some redundancy to get
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| 48 | # rid of.
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| 49 | if pnode.tok:
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| 50 | if isinstance(pnode.tok, Token):
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| 51 | v = lexer.TokenVal(pnode.tok)
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| 52 | else:
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| 53 | # e.g. CommandSub for x = $(echo hi)
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| 54 | v = repr(pnode.tok)
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| 55 | else:
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| 56 | v = '-'
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| 57 | self.f.write('%s%d %s %s\n' % (ind, i, self.names[pnode.typ], v))
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| 58 | if pnode.children is not None:
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| 59 | for i, child in enumerate(pnode.children):
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| 60 | self._Print(child, indent + 1, i)
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| 61 |
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| 62 | def Print(self, pnode):
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| 63 | # type: (PNode) -> None
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| 64 | self._Print(pnode, 0, 0)
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| 65 |
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| 66 |
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| 67 | def _Classify(gr, tok):
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| 68 | # type: (Grammar, Token) -> int
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| 69 |
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| 70 | # We have to match up what ParserGenerator.make_grammar() did when
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| 71 | # calling make_label() and make_first(). See classify() in
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| 72 | # opy/pgen2/driver.py.
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| 73 |
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| 74 | id_ = tok.id # mycpp fix: we need C++ to do uint16_t -> int conversion
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| 75 |
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| 76 | # TODO: use something more efficient than a Dict
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| 77 | if id_ in gr.tokens:
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| 78 | return gr.tokens[id_]
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| 79 |
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| 80 | if id_ == Id.Unknown_DEqual:
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| 81 | p_die('Use === to be exact, or ~== to convert types', tok)
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| 82 |
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| 83 | if id_ == Id.Unknown_DAmp:
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| 84 | p_die("Use 'and' in expression mode (OILS-ERR-15)", tok)
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| 85 | if id_ == Id.Unknown_DPipe:
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| 86 | p_die("Use 'or' in expression mode (OILS-ERR-15)", tok)
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| 87 | # Not possible to check '!' as it conflicts with Id.Expr_Bang
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| 88 |
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| 89 | if id_ == Id.Unknown_DDot:
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| 90 | p_die(
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| 91 | 'Use ..< for half-open range, or ..= for closed range (OILS-ERR-16)',
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| 92 | tok)
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| 93 |
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| 94 | if id_ == Id.Unknown_Tok:
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| 95 | type_str = ''
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| 96 | else:
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| 97 | type_str = ' (%s)' % ui.PrettyId(tok.id)
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| 98 | p_die('Unexpected token in expression mode%s' % type_str, tok)
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| 99 |
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| 100 |
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| 101 | # Newlines are ignored between these pairs.
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| 102 | # yapf: disable
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| 103 | _OTHER_BALANCE = {
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| 104 |
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| 105 | # Parenthesized expressions (tuples) and func/proc parameter lists
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| 106 | Id.Op_LParen: 1,
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| 107 | Id.Op_RParen: -1,
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| 108 | Id.Op_LBracket: 1,
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| 109 | Id.Op_RBracket: -1,
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| 110 |
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| 111 | # Dicts are {}, and the grammar respects Op_Newline.
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| 112 | }
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| 113 | # yapf: enable
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| 114 |
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| 115 |
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| 116 | def _PushYshTokens(parse_ctx, gr, p, lex):
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| 117 | # type: (ParseContext, Grammar, parse.Parser, Lexer) -> Token
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| 118 | """Push tokens onto pgen2's parser.
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| 119 |
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| 120 | Returns the last token so it can be reused/seen by the CommandParser.
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| 121 | """
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| 122 | #log('keywords = %s', gr.keywords)
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| 123 | #log('tokens = %s', gr.tokens)
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| 124 |
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| 125 | last_token = None # type: Optional[Token]
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| 126 | prev_was_newline = False
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| 127 |
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| 128 | balance = 0 # to ignore newlines
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| 129 |
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| 130 | while True:
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| 131 | if last_token: # e.g. left over from WordParser
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| 132 | tok = last_token
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| 133 | #log('last_token = %s', last_token)
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| 134 | last_token = None
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| 135 | else:
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| 136 | tok = lex.Read(lex_mode_e.Expr)
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| 137 | #log('tok = %s', tok)
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| 138 |
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| 139 | # Comments and whitespace. Newlines aren't ignored.
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| 140 | if consts.GetKind(tok.id) == Kind.Ignored:
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| 141 | continue
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| 142 |
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| 143 | # For multiline lists, maps, etc.
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| 144 | if tok.id == Id.Op_Newline:
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| 145 | if balance > 0:
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| 146 | #log('*** SKIPPING NEWLINE')
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| 147 | continue
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| 148 | # Eliminate duplicate newline tokens. It makes the grammar simpler, and
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| 149 | # it's consistent with CPython's lexer and our own WordParser.
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| 150 | if prev_was_newline:
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| 151 | continue
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| 152 | prev_was_newline = True
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| 153 | else:
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| 154 | prev_was_newline = False
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| 155 |
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| 156 | balance += _OTHER_BALANCE.get(tok.id, 0)
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| 157 | #log('BALANCE after seeing %s = %d', tok.id, balance)
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| 158 |
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| 159 | if tok.id == Id.Op_LParen:
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| 160 | # For nesting inside $()
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| 161 | lex.PushHint(Id.Op_RParen, Id.Op_RParen)
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| 162 |
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| 163 | #if tok.id == Id.Expr_Name and tok.val in KEYWORDS:
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| 164 | # tok.id = KEYWORDS[tok.val]
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| 165 | # log('Replaced with %s', tok.id)
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| 166 |
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| 167 | assert tok.id < 256, Id_str(tok.id)
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| 168 |
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| 169 | ilabel = _Classify(gr, tok)
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| 170 | #log('tok = %s, ilabel = %d', tok, ilabel)
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| 171 |
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| 172 | if p.addtoken(tok.id, tok, ilabel):
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| 173 | return tok
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| 174 |
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| 175 | #
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| 176 | # Mututally recursive calls into the command/word parsers.
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| 177 | #
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| 178 |
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| 179 | if tok.id in (Id.Left_ColonPipe,
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| 180 | Id.Left_PercentParen): # :| %( LEGACY!
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| 181 | left_tok = tok
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| 182 | if tok.id == Id.Left_PercentParen:
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| 183 | lex.PushHint(Id.Op_RParen, Id.Right_ShArrayLiteral)
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| 184 |
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| 185 | # Blame the opening token
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| 186 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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| 187 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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| 188 | words = [] # type: List[CompoundWord]
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| 189 | close_tok = None # type: Optional[Token]
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| 190 | done = False
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| 191 | while not done:
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| 192 | w = w_parser.ReadWord(lex_mode_e.ShCommand)
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| 193 | with tagswitch(w) as case:
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| 194 | if case(word_e.Operator):
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| 195 | tok = cast(Token, w)
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| 196 | if tok.id == Id.Right_ShArrayLiteral:
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| 197 | if left_tok.id != Id.Left_PercentParen:
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| 198 | p_die('Expected ) to close', left_tok)
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| 199 | close_tok = tok
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| 200 | done = True # can't use break here
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| 201 | elif tok.id == Id.Op_Pipe:
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| 202 | if left_tok.id != Id.Left_ColonPipe:
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| 203 | p_die('Expected ) to close', left_tok)
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| 204 | close_tok = tok
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| 205 | done = True # can't use break here
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| 206 | elif tok.id == Id.Op_Newline: # internal newlines allowed
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| 207 | continue
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| 208 | else:
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| 209 | p_die('Unexpected token in array literal',
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| 210 | loc.Word(w))
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| 211 |
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| 212 | elif case(word_e.Compound):
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| 213 | words.append(cast(CompoundWord, w))
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| 214 |
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| 215 | else:
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| 216 | raise AssertionError()
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| 217 |
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| 218 | words2 = braces.BraceDetectAll(words)
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| 219 | words3 = word_.TildeDetectAll(words2)
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| 220 |
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| 221 | typ = Id.Expr_CastedDummy
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| 222 |
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| 223 | lit_part = ShArrayLiteral(left_tok, words3, close_tok)
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| 224 | opaque = cast(Token, lit_part) # HACK for expr_to_ast
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| 225 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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| 226 | assert not done # can't end the expression
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| 227 |
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| 228 | # Now push the closing )
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| 229 | ilabel = _Classify(gr, close_tok)
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| 230 | done = p.addtoken(tok.id, close_tok, ilabel)
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| 231 | assert not done # can't end the expression
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| 232 |
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| 233 | continue
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| 234 |
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| 235 | # $( @( ^(
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| 236 | if tok.id in (Id.Left_DollarParen, Id.Left_AtParen,
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| 237 | Id.Left_CaretParen):
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| 238 |
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| 239 | left_token = tok
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| 240 |
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| 241 | lex.PushHint(Id.Op_RParen, Id.Eof_RParen)
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| 242 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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| 243 | c_parser = parse_ctx.MakeParserForCommandSub(
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| 244 | line_reader, lex, Id.Eof_RParen)
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| 245 | node = c_parser.ParseCommandSub()
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| 246 | # A little gross: Copied from osh/word_parse.py
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| 247 | right_token = c_parser.w_parser.cur_token
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| 248 |
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| 249 | cs_part = CommandSub(left_token, node, right_token)
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| 250 |
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| 251 | typ = Id.Expr_CastedDummy
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| 252 | opaque = cast(Token, cs_part) # HACK for expr_to_ast
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| 253 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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| 254 | assert not done # can't end the expression
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| 255 |
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| 256 | # Now push the closing )
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| 257 | ilabel = _Classify(gr, right_token)
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| 258 | done = p.addtoken(right_token.id, right_token, ilabel)
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| 259 | assert not done # can't end the expression
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| 260 |
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| 261 | continue
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| 262 |
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| 263 | # " $" """ $""" ^"
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| 264 | if tok.id in (Id.Left_DoubleQuote, Id.Left_DollarDoubleQuote,
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| 265 | Id.Left_TDoubleQuote, Id.Left_DollarTDoubleQuote,
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| 266 | Id.Left_CaretDoubleQuote):
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| 267 |
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| 268 | left_token = tok
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| 269 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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| 270 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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| 271 |
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| 272 | parts = [] # type: List[word_part_t]
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| 273 | last_token = w_parser.ReadDoubleQuoted(left_token, parts)
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| 274 | expr_dq_part = DoubleQuoted(left_token, parts, last_token)
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| 275 |
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| 276 | typ = Id.Expr_CastedDummy
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| 277 | opaque = cast(Token, expr_dq_part) # HACK for expr_to_ast
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| 278 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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| 279 | assert not done # can't end the expression
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| 280 |
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| 281 | continue
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| 282 |
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| 283 | # ${
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| 284 | if tok.id == Id.Left_DollarBrace:
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| 285 | left_token = tok
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| 286 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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| 287 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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| 288 |
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| 289 | part, last_token = w_parser.ReadBracedVarSub(left_token)
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| 290 |
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| 291 | # It's casted word_part.BracedVarSub -> dummy -> expr.BracedVarSub!
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| 292 | typ = Id.Expr_CastedDummy
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| 293 | opaque = cast(Token, part) # HACK for expr_to_ast
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| 294 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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| 295 | assert not done # can't end the expression
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| 296 |
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| 297 | continue
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| 298 |
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| 299 | # 'x' '''x'''
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| 300 | # r'x' r'''x'''
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| 301 | # u'x' u'''x'''
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| 302 | # b'x' b'''x'''
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| 303 | # $'x'
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| 304 | if tok.id in (Id.Left_SingleQuote, Id.Left_TSingleQuote,
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| 305 | Id.Left_RSingleQuote, Id.Left_RTSingleQuote,
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| 306 | Id.Left_USingleQuote, Id.Left_UTSingleQuote,
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| 307 | Id.Left_BSingleQuote, Id.Left_BTSingleQuote,
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| 308 | Id.Left_DollarSingleQuote):
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| 309 | if tok.id == Id.Left_DollarSingleQuote:
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| 310 | sq_mode = lex_mode_e.SQ_C
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| 311 | elif tok.id in (Id.Left_USingleQuote, Id.Left_UTSingleQuote,
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| 312 | Id.Left_BSingleQuote, Id.Left_BTSingleQuote):
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| 313 | sq_mode = lex_mode_e.J8_Str
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| 314 | else:
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| 315 | sq_mode = lex_mode_e.SQ_Raw
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| 316 |
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| 317 | left_token = tok
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| 318 | line_reader = reader.DisallowedLineReader(parse_ctx.arena, tok)
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| 319 | w_parser = parse_ctx.MakeWordParser(lex, line_reader)
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| 320 |
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| 321 | tokens = [] # type: List[Token]
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| 322 | last_token = w_parser.ReadSingleQuoted(sq_mode, left_token, tokens,
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| 323 | True)
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| 324 |
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| 325 | sval = word_compile.EvalSingleQuoted(left_token.id, tokens)
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| 326 | sq_part = SingleQuoted(left_token, sval, last_token)
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| 327 |
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| 328 | typ = Id.Expr_CastedDummy
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| 329 | opaque = cast(Token, sq_part) # HACK for expr_to_ast
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| 330 | done = p.addtoken(typ, opaque, gr.tokens[typ])
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| 331 | assert not done # can't end the expression
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| 332 | continue
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| 333 |
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| 334 | else:
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| 335 | # We never broke out -- EOF is too soon (how can this happen???)
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| 336 | raise parse.ParseError("incomplete input", tok.id, tok)
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| 337 |
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| 338 |
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| 339 | class ExprParser(object):
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| 340 | """A wrapper around a pgen2 parser."""
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| 341 |
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| 342 | def __init__(self, parse_ctx, gr):
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| 343 | # type: (ParseContext, Grammar) -> None
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| 344 | self.parse_ctx = parse_ctx
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| 345 | self.gr = gr
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| 346 | # Reused multiple times.
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| 347 | self.push_parser = parse.Parser(gr)
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| 348 | self.pnode_alloc = None # type: Optional[PNodeAllocator]
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| 349 |
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| 350 | def Parse(self, lexer, start_symbol):
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| 351 | # type: (Lexer, int) -> Tuple[PNode, Token]
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| 352 |
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| 353 | # Reuse the parser
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| 354 | self.push_parser.setup(start_symbol, self.pnode_alloc)
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| 355 | try:
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| 356 | last_token = _PushYshTokens(self.parse_ctx, self.gr,
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| 357 | self.push_parser, lexer)
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| 358 | except parse.ParseError as e:
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| 359 | #log('ERROR %s', e)
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| 360 | # TODO:
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| 361 | # - Describe what lexer mode we're in (Invalid syntax in regex)
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| 362 | # - Maybe say where the mode started
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| 363 | # - Id.Unknown_Tok could say "This character is invalid"
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| 364 |
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| 365 | # ParseError has a "too much input" case but I haven't been able to
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| 366 | # tickle it. Maybe it's because of the Eof tokens?
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| 367 |
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| 368 | p_die(
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| 369 | 'Syntax error in expression (near %s)' % ui.PrettyId(e.tok.id),
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| 370 | e.tok)
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| 371 |
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| 372 | return self.push_parser.rootnode, last_token
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| 373 |
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| 374 |
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| 375 | class ctx_PNodeAllocator(object):
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| 376 |
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| 377 | def __init__(self, ep):
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| 378 | # type: (ExprParser) -> None
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| 379 | self.expr_parser = ep
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| 380 | self.expr_parser.pnode_alloc = PNodeAllocator()
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| 381 |
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| 382 | def __enter__(self):
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| 383 | # type: () -> None
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| 384 | pass
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| 385 |
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| 386 | def __exit__(self, type, value, traceback):
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| 387 | # type: (Any, Any, Any) -> None
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| 388 | self.expr_parser.pnode_alloc.Clear()
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| 389 | self.expr_parser.pnode_alloc = None
|