| 1 | """YSH Str methods"""
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| 2 |
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| 3 | from __future__ import print_function
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| 4 |
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| 5 | from _devbuild.gen.syntax_asdl import loc_t
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| 6 | from _devbuild.gen.value_asdl import (value, value_e, value_t, eggex_ops,
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| 7 | eggex_ops_t, RegexMatch)
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| 8 | from core import error
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| 9 | from core import state
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| 10 | from core import vm
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| 11 | from frontend import typed_args
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| 12 | from mycpp import mops
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| 13 | from mycpp.mylib import log, tagswitch
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| 14 | from osh import string_ops
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| 15 | from ysh import expr_eval
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| 16 | from ysh import regex_translate
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| 17 | from ysh import val_ops
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| 18 |
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| 19 | import libc
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| 20 | from libc import REG_NOTBOL
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| 21 |
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| 22 | from typing import cast, Dict, List, Tuple
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| 23 |
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| 24 | _ = log
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| 25 |
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| 26 |
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| 27 | def _StrMatchStart(s, p):
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| 28 | # type: (str, str) -> Tuple[bool, int, int]
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| 29 | """Returns the range of bytes in 's' that match string pattern `p`. the
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| 30 | pattern matches if 's' starts with all the characters in 'p'.
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| 31 |
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| 32 | The returned match result is the tuple "(matched, begin, end)". 'matched'
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| 33 | is true if the pattern matched. 'begin' and 'end' give the half-open range
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| 34 | "[begin, end)" of byte indices from 's' for the match, and are a valid but
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| 35 | empty range if 'match' is false.
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| 36 |
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| 37 | Used for shell functions like 'trimStart' when trimming a prefix string.
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| 38 | """
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| 39 | if s.startswith(p):
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| 40 | return (True, 0, len(p))
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| 41 | else:
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| 42 | return (False, 0, 0)
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| 43 |
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| 44 |
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| 45 | def _StrMatchEnd(s, p):
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| 46 | # type: (str, str) -> Tuple[bool, int, int]
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| 47 | """Returns a match result for the bytes in 's' that match string pattern
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| 48 | `p`. the pattern matches if 's' ends with all the characters in 'p'.
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| 49 |
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| 50 | The returned match result is the tuple "(matched, begin, end)". 'matched'
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| 51 | is true if the pattern matched. 'begin' and 'end' give the half-open range
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| 52 | "[begin, end)" of byte indices from 's' for the match, and are a valid but
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| 53 | empty range if 'match' is false.
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| 54 |
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| 55 | Used for shell functions like 'trimEnd' when trimming a suffix string.
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| 56 | """
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| 57 | len_s = len(s)
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| 58 | if s.endswith(p):
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| 59 | return (True, len_s - len(p), len_s)
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| 60 | else:
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| 61 | return (False, len_s, len_s)
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| 62 |
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| 63 |
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| 64 | def _EggexMatchCommon(s, p, ere, empty_p):
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| 65 | # type: (str, value.Eggex, str, int) -> Tuple[bool, int, int]
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| 66 | cflags = regex_translate.LibcFlags(p.canonical_flags)
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| 67 | eflags = 0
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| 68 | indices = libc.regex_search(ere, cflags, s, eflags)
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| 69 | if indices is None:
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| 70 | return (False, empty_p, empty_p)
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| 71 |
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| 72 | start = indices[0]
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| 73 | end = indices[1]
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| 74 |
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| 75 | return (True, start, end)
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| 76 |
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| 77 |
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| 78 | def _EggexMatchStart(s, p):
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| 79 | # type: (str, value.Eggex) -> Tuple[bool, int, int]
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| 80 | """Returns a match result for the bytes in 's' that match Eggex pattern
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| 81 | `p` when constrained to match at the start of the string.
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| 82 |
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| 83 | Any capturing done by the Eggex pattern is ignored.
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| 84 |
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| 85 | The returned match result is the tuple "(matched, begin, end)". 'matched'
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| 86 | is true if the pattern matched. 'begin' and 'end' give the half-open range
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| 87 | "[begin, end)" of byte indices from 's' for the match, and are a valid but
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| 88 | empty range if 'match' is false.
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| 89 |
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| 90 | Used for shell functions like 'trimStart' when trimming with an Eggex
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| 91 | pattern.
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| 92 | """
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| 93 | ere = regex_translate.AsPosixEre(p)
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| 94 | if not ere.startswith('^'):
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| 95 | ere = '^' + ere
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| 96 | return _EggexMatchCommon(s, p, ere, 0)
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| 97 |
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| 98 |
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| 99 | def _EggexMatchEnd(s, p):
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| 100 | # type: (str, value.Eggex) -> Tuple[bool, int, int]
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| 101 | """Like _EggexMatchStart, but matches against the end of the
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| 102 | string.
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| 103 | """
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| 104 | ere = regex_translate.AsPosixEre(p)
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| 105 | if not ere.endswith('$'):
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| 106 | ere = ere + '$'
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| 107 | return _EggexMatchCommon(s, p, ere, len(s))
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| 108 |
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| 109 |
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| 110 | START = 0b01
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| 111 | END = 0b10
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| 112 |
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| 113 |
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| 114 | class HasAffix(vm._Callable):
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| 115 | """ Implements `startsWith()`, `endsWith()`. """
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| 116 |
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| 117 | def __init__(self, anchor):
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| 118 | # type: (int) -> None
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| 119 | assert anchor in (START, END), ("Anchor must be START or END")
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| 120 | self.anchor = anchor
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| 121 |
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| 122 | def Call(self, rd):
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| 123 | # type: (typed_args.Reader) -> value_t
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| 124 | """
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| 125 | string => startsWith(pattern_str) # => bool
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| 126 | string => startsWith(pattern_eggex) # => bool
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| 127 | string => endsWith(pattern_str) # => bool
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| 128 | string => endsWith(pattern_eggex) # => bool
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| 129 | """
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| 130 |
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| 131 | string = rd.PosStr()
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| 132 | pattern_val = rd.PosValue()
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| 133 | pattern_str = None # type: str
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| 134 | pattern_eggex = None # type: value.Eggex
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| 135 | with tagswitch(pattern_val) as case:
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| 136 | if case(value_e.Eggex):
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| 137 | pattern_eggex = cast(value.Eggex, pattern_val)
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| 138 | elif case(value_e.Str):
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| 139 | pattern_str = cast(value.Str, pattern_val).s
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| 140 | else:
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| 141 | raise error.TypeErr(pattern_val,
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| 142 | 'expected pattern to be Eggex or Str',
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| 143 | rd.LeftParenToken())
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| 144 | rd.Done()
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| 145 |
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| 146 | matched = False
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| 147 | try:
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| 148 | if pattern_str is not None:
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| 149 | if self.anchor & START:
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| 150 | matched, _, _ = _StrMatchStart(string, pattern_str)
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| 151 | else:
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| 152 | matched, _, _ = _StrMatchEnd(string, pattern_str)
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| 153 | else:
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| 154 | assert pattern_eggex is not None
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| 155 | if self.anchor & START:
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| 156 | matched, _, _ = _EggexMatchStart(string, pattern_eggex)
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| 157 | else:
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| 158 | matched, _, _ = _EggexMatchEnd(string, pattern_eggex)
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| 159 | except error.Strict as e:
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| 160 | raise error.Expr(e.msg, e.location)
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| 161 |
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| 162 | return value.Bool(matched)
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| 163 |
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| 164 |
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| 165 | class Trim(vm._Callable):
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| 166 | """ Implements `trimStart()`, `trimEnd()`, and `trim()` """
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| 167 |
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| 168 | def __init__(self, anchor):
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| 169 | # type: (int) -> None
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| 170 | assert anchor in (START, END, START
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| 171 | | END), ("Anchor must be START, END, or START|END")
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| 172 | self.anchor = anchor
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| 173 |
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| 174 | def Call(self, rd):
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| 175 | # type: (typed_args.Reader) -> value_t
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| 176 | """
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| 177 | string => trimStart() # => Str
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| 178 | string => trimEnd() # => Str
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| 179 | string => trim() # => Str
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| 180 | string => trimStart(pattern_str) # => Str
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| 181 | string => trimEnd(pattern_str) # => Str
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| 182 | string => trim(pattern_str) # => Str
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| 183 | string => trimStart(pattern_eggex) # => Str
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| 184 | string => trimEnd(pattern_eggex) # => Str
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| 185 | string => trim(pattern_eggex) # => Str
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| 186 | """
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| 187 |
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| 188 | string = rd.PosStr()
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| 189 | pattern_val = rd.OptionalValue()
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| 190 | pattern_str = None # type: str
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| 191 | pattern_eggex = None # type: value.Eggex
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| 192 | if pattern_val:
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| 193 | with tagswitch(pattern_val) as case:
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| 194 | if case(value_e.Eggex):
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| 195 | pattern_eggex = cast(value.Eggex, pattern_val)
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| 196 | elif case(value_e.Str):
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| 197 | pattern_str = cast(value.Str, pattern_val).s
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| 198 | else:
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| 199 | raise error.TypeErr(pattern_val,
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| 200 | 'expected pattern to be Eggex or Str',
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| 201 | rd.LeftParenToken())
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| 202 | rd.Done()
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| 203 |
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| 204 | start = 0
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| 205 | end = len(string)
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| 206 | try:
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| 207 | if pattern_str is not None:
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| 208 | if self.anchor & START:
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| 209 | _, _, start = _StrMatchStart(string, pattern_str)
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| 210 | if self.anchor & END:
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| 211 | _, end, _ = _StrMatchEnd(string, pattern_str)
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| 212 | elif pattern_eggex is not None:
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| 213 | if self.anchor & START:
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| 214 | _, _, start = _EggexMatchStart(string, pattern_eggex)
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| 215 | if self.anchor & END:
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| 216 | _, end, _ = _EggexMatchEnd(string, pattern_eggex)
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| 217 | else:
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| 218 | if self.anchor & START:
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| 219 | _, start = string_ops.StartsWithWhitespaceByteRange(string)
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| 220 | if self.anchor & END:
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| 221 | end, _ = string_ops.EndsWithWhitespaceByteRange(string)
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| 222 | except error.Strict as e:
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| 223 | raise error.Expr(e.msg, e.location)
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| 224 |
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| 225 | res = string[start:end]
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| 226 | return value.Str(res)
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| 227 |
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| 228 |
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| 229 | class Upper(vm._Callable):
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| 230 |
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| 231 | def __init__(self):
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| 232 | # type: () -> None
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| 233 | pass
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| 234 |
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| 235 | def Call(self, rd):
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| 236 | # type: (typed_args.Reader) -> value_t
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| 237 |
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| 238 | s = rd.PosStr()
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| 239 | rd.Done()
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| 240 |
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| 241 | # TODO: unicode support
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| 242 | return value.Str(s.upper())
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| 243 |
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| 244 |
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| 245 | class Lower(vm._Callable):
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| 246 |
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| 247 | def __init__(self):
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| 248 | # type: () -> None
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| 249 | pass
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| 250 |
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| 251 | def Call(self, rd):
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| 252 | # type: (typed_args.Reader) -> value_t
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| 253 |
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| 254 | s = rd.PosStr()
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| 255 | rd.Done()
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| 256 |
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| 257 | # TODO: unicode support
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| 258 | return value.Str(s.lower())
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| 259 |
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| 260 |
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| 261 | SEARCH = 0
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| 262 | LEFT_MATCH = 1
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| 263 |
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| 264 |
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| 265 | class SearchMatch(vm._Callable):
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| 266 |
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| 267 | def __init__(self, which_method):
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| 268 | # type: (int) -> None
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| 269 | self.which_method = which_method
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| 270 |
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| 271 | def Call(self, rd):
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| 272 | # type: (typed_args.Reader) -> value_t
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| 273 | """
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| 274 | s => search(eggex, pos=0)
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| 275 | """
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| 276 | string = rd.PosStr()
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| 277 |
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| 278 | pattern = rd.PosValue() # Eggex or ERE Str
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| 279 | with tagswitch(pattern) as case:
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| 280 | if case(value_e.Eggex):
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| 281 | eggex_val = cast(value.Eggex, pattern)
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| 282 |
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| 283 | # lazily converts to ERE
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| 284 | ere = regex_translate.AsPosixEre(eggex_val)
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| 285 | cflags = regex_translate.LibcFlags(eggex_val.canonical_flags)
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| 286 | capture = eggex_ops.Yes(
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| 287 | eggex_val.convert_funcs, eggex_val.convert_toks,
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| 288 | eggex_val.capture_names) # type: eggex_ops_t
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| 289 |
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| 290 | elif case(value_e.Str):
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| 291 | ere = cast(value.Str, pattern).s
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| 292 | cflags = 0
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| 293 | capture = eggex_ops.No
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| 294 |
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| 295 | else:
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| 296 | # TODO: add method name to this error
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| 297 | raise error.TypeErr(pattern, 'expected Eggex or Str',
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| 298 | rd.LeftParenToken())
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| 299 |
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| 300 | # It's called 'pos', not 'start' like Python. Python has 2 kinds of
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| 301 | # 'start' in its regex API, which can be confusing.
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| 302 | pos = mops.BigTruncate(rd.NamedInt('pos', 0))
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| 303 | rd.Done()
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| 304 |
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| 305 | # Make it anchored
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| 306 | if self.which_method == LEFT_MATCH and not ere.startswith('^'):
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| 307 | ere = '^' + ere
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| 308 |
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| 309 | if self.which_method == LEFT_MATCH:
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| 310 | eflags = 0 # ^ matches beginning even if pos=5
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| 311 | else:
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| 312 | eflags = 0 if pos == 0 else REG_NOTBOL # ^ only matches when pos=0
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| 313 |
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| 314 | indices = libc.regex_search(ere, cflags, string, eflags, pos)
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| 315 |
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| 316 | if indices is None:
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| 317 | return value.Null
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| 318 |
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| 319 | return RegexMatch(string, indices, capture)
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| 320 |
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| 321 |
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| 322 | class Replace(vm._Callable):
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| 323 |
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| 324 | def __init__(self, mem, expr_ev):
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| 325 | # type: (state.Mem, expr_eval.ExprEvaluator) -> None
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| 326 | self.mem = mem
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| 327 | self.expr_ev = expr_ev
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| 328 |
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| 329 | def EvalSubstExpr(self, expr, blame_loc):
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| 330 | # type: (value.Expr, loc_t) -> str
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| 331 | res = self.expr_ev.EvalExpr(expr.e, blame_loc)
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| 332 | if res.tag() == value_e.Str:
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| 333 | return cast(value.Str, res).s
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| 334 |
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| 335 | raise error.TypeErr(res, "expected expr to eval to a Str", blame_loc)
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| 336 |
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| 337 | def Call(self, rd):
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| 338 | # type: (typed_args.Reader) -> value_t
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| 339 | """
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| 340 | s => replace(string_val, subst_str, count=-1)
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| 341 | s => replace(string_val, subst_expr, count=-1)
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| 342 | s => replace(eggex_val, subst_str, count=-1)
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| 343 | s => replace(eggex_val, subst_expr, count=-1)
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| 344 |
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| 345 | For count in [0, MAX_INT], there will be no more than count
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| 346 | replacements. Any negative count should read as unset, and replace will
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| 347 | replace all occurances of the pattern.
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| 348 | """
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| 349 | string = rd.PosStr()
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| 350 |
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| 351 | string_val = None # type: value.Str
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| 352 | eggex_val = None # type: value.Eggex
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| 353 | subst_str = None # type: value.Str
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| 354 | subst_expr = None # type: value.Expr
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| 355 |
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| 356 | pattern = rd.PosValue()
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| 357 | with tagswitch(pattern) as case:
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| 358 | if case(value_e.Eggex):
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| 359 | # HACK: mycpp will otherwise generate:
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| 360 | # value::Eggex* eggex_val ...
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| 361 | eggex_val_ = cast(value.Eggex, pattern)
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| 362 | eggex_val = eggex_val_
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| 363 |
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| 364 | elif case(value_e.Str):
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| 365 | string_val_ = cast(value.Str, pattern)
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| 366 | string_val = string_val_
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| 367 |
|
| 368 | else:
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| 369 | raise error.TypeErr(pattern,
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| 370 | 'expected pattern to be Eggex or Str',
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| 371 | rd.LeftParenToken())
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| 372 |
|
| 373 | subst = rd.PosValue()
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| 374 | with tagswitch(subst) as case:
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| 375 | if case(value_e.Str):
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| 376 | subst_str_ = cast(value.Str, subst)
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| 377 | subst_str = subst_str_
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| 378 |
|
| 379 | elif case(value_e.Expr):
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| 380 | subst_expr_ = cast(value.Expr, subst)
|
| 381 | subst_expr = subst_expr_
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| 382 |
|
| 383 | else:
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| 384 | raise error.TypeErr(subst,
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| 385 | 'expected substitution to be Str or Expr',
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| 386 | rd.LeftParenToken())
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| 387 |
|
| 388 | count = mops.BigTruncate(rd.NamedInt("count", -1))
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| 389 | rd.Done()
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| 390 |
|
| 391 | if count == 0:
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| 392 | return value.Str(string)
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| 393 |
|
| 394 | if string_val:
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| 395 | if subst_str:
|
| 396 | s = subst_str.s
|
| 397 | if subst_expr:
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| 398 | # Eval with $0 set to string_val (the matched substring)
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| 399 | with state.ctx_Eval(self.mem, string_val.s, None, None):
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| 400 | s = self.EvalSubstExpr(subst_expr, rd.LeftParenToken())
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| 401 | assert s is not None
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| 402 |
|
| 403 | result = string.replace(string_val.s, s, count)
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| 404 |
|
| 405 | return value.Str(result)
|
| 406 |
|
| 407 | if eggex_val:
|
| 408 | if '\0' in string:
|
| 409 | raise error.Structured(
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| 410 | 3,
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| 411 | "cannot replace by eggex on a string with NUL bytes",
|
| 412 | rd.LeftParenToken())
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| 413 |
|
| 414 | ere = regex_translate.AsPosixEre(eggex_val)
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| 415 | cflags = regex_translate.LibcFlags(eggex_val.canonical_flags)
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| 416 |
|
| 417 | # Walk through the string finding all matches of the compiled ere.
|
| 418 | # Then, collect unmatched substrings and substitutions into the
|
| 419 | # `parts` list.
|
| 420 | pos = 0
|
| 421 | parts = [] # type: List[str]
|
| 422 | replace_count = 0
|
| 423 | while pos < len(string):
|
| 424 | indices = libc.regex_search(ere, cflags, string, 0, pos)
|
| 425 | if indices is None:
|
| 426 | break
|
| 427 |
|
| 428 | # Collect captures
|
| 429 | arg0 = None # type: str
|
| 430 | argv = [] # type: List[str]
|
| 431 | named_vars = {} # type: Dict[str, value_t]
|
| 432 | num_groups = len(indices) / 2
|
| 433 | for group in xrange(num_groups):
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| 434 | start = indices[2 * group]
|
| 435 | end = indices[2 * group + 1]
|
| 436 | captured = string[start:end]
|
| 437 | val = value.Str(captured) # type: value_t
|
| 438 |
|
| 439 | if len(eggex_val.convert_funcs) and group != 0:
|
| 440 | convert_func = eggex_val.convert_funcs[group - 1]
|
| 441 | convert_tok = eggex_val.convert_toks[group - 1]
|
| 442 |
|
| 443 | if convert_func:
|
| 444 | val = self.expr_ev.CallConvertFunc(
|
| 445 | convert_func, val, convert_tok,
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| 446 | rd.LeftParenToken())
|
| 447 |
|
| 448 | # $0, $1, $2 variables are argv values, which must be
|
| 449 | # strings. Furthermore, they can only be used in string
|
| 450 | # contexts
|
| 451 | # eg. "$[1]" != "$1".
|
| 452 | val_str = val_ops.Stringify(val, rd.LeftParenToken())
|
| 453 | if group == 0:
|
| 454 | arg0 = val_str
|
| 455 | else:
|
| 456 | argv.append(val_str)
|
| 457 |
|
| 458 | # $0 cannot be named
|
| 459 | if group != 0:
|
| 460 | name = eggex_val.capture_names[group - 2]
|
| 461 | if name is not None:
|
| 462 | named_vars[name] = val
|
| 463 |
|
| 464 | if subst_str:
|
| 465 | s = subst_str.s
|
| 466 | if subst_expr:
|
| 467 | with state.ctx_Eval(self.mem, arg0, argv, named_vars):
|
| 468 | s = self.EvalSubstExpr(subst_expr, rd.LeftParenToken())
|
| 469 | assert s is not None
|
| 470 |
|
| 471 | start = indices[0]
|
| 472 | end = indices[1]
|
| 473 | if pos == end:
|
| 474 | raise error.Structured(
|
| 475 | 3,
|
| 476 | "eggex should never match the empty string",
|
| 477 | rd.LeftParenToken())
|
| 478 |
|
| 479 | parts.append(string[pos:start]) # Unmatched substring
|
| 480 | parts.append(s) # Replacement
|
| 481 | pos = end # Move to end of match
|
| 482 |
|
| 483 | replace_count += 1
|
| 484 | if count != -1 and replace_count == count:
|
| 485 | break
|
| 486 |
|
| 487 | parts.append(string[pos:]) # Remaining unmatched substring
|
| 488 |
|
| 489 | return value.Str("".join(parts))
|
| 490 |
|
| 491 | raise AssertionError()
|
| 492 |
|
| 493 |
|
| 494 | class Split(vm._Callable):
|
| 495 |
|
| 496 | def __init__(self):
|
| 497 | # type: () -> None
|
| 498 | pass
|
| 499 |
|
| 500 | def Call(self, rd):
|
| 501 | # type: (typed_args.Reader) -> value_t
|
| 502 | """
|
| 503 | s.split(string_sep, count=-1)
|
| 504 | s.split(eggex_sep, count=-1)
|
| 505 |
|
| 506 | Count behaves like in replace() in that:
|
| 507 | - `count` < 0 -> ignore
|
| 508 | - `count` >= 0 -> there will be at most `count` splits
|
| 509 | """
|
| 510 | string = rd.PosStr()
|
| 511 |
|
| 512 | string_sep = None # type: str
|
| 513 | eggex_sep = None # type: value.Eggex
|
| 514 |
|
| 515 | sep = rd.PosValue()
|
| 516 | with tagswitch(sep) as case:
|
| 517 | if case(value_e.Eggex):
|
| 518 | eggex_sep_ = cast(value.Eggex, sep)
|
| 519 | eggex_sep = eggex_sep_
|
| 520 |
|
| 521 | elif case(value_e.Str):
|
| 522 | string_sep_ = cast(value.Str, sep)
|
| 523 | string_sep = string_sep_.s
|
| 524 |
|
| 525 | else:
|
| 526 | raise error.TypeErr(sep, 'expected separator to be Eggex or Str',
|
| 527 | rd.LeftParenToken())
|
| 528 |
|
| 529 | count = mops.BigTruncate(rd.NamedInt("count", -1))
|
| 530 | rd.Done()
|
| 531 |
|
| 532 | if len(string) == 0:
|
| 533 | return value.List([])
|
| 534 |
|
| 535 | if string_sep is not None:
|
| 536 | if len(string_sep) == 0:
|
| 537 | raise error.Structured(3, "separator must be non-empty",
|
| 538 | rd.LeftParenToken())
|
| 539 |
|
| 540 | cursor = 0
|
| 541 | chunks = [] # type: List[value_t]
|
| 542 | while cursor < len(string) and count != 0:
|
| 543 | next = string.find(string_sep, cursor)
|
| 544 | if next == -1:
|
| 545 | break
|
| 546 |
|
| 547 | chunks.append(value.Str(string[cursor:next]))
|
| 548 | cursor = next + len(string_sep)
|
| 549 | count -= 1
|
| 550 |
|
| 551 | chunks.append(value.Str(string[cursor:]))
|
| 552 |
|
| 553 | return value.List(chunks)
|
| 554 |
|
| 555 | if eggex_sep is not None:
|
| 556 | if '\0' in string:
|
| 557 | raise error.Structured(
|
| 558 | 3, "cannot split a string with a NUL byte",
|
| 559 | rd.LeftParenToken())
|
| 560 |
|
| 561 | regex = regex_translate.AsPosixEre(eggex_sep)
|
| 562 | cflags = regex_translate.LibcFlags(eggex_sep.canonical_flags)
|
| 563 |
|
| 564 | cursor = 0
|
| 565 | chunks = []
|
| 566 | while cursor < len(string) and count != 0:
|
| 567 | m = libc.regex_search(regex, cflags, string, 0, cursor)
|
| 568 | if m is None:
|
| 569 | break
|
| 570 |
|
| 571 | start = m[0]
|
| 572 | end = m[1]
|
| 573 | if start == end:
|
| 574 | raise error.Structured(
|
| 575 | 3,
|
| 576 | "eggex separators should never match the empty string",
|
| 577 | rd.LeftParenToken())
|
| 578 |
|
| 579 | chunks.append(value.Str(string[cursor:start]))
|
| 580 | cursor = end
|
| 581 |
|
| 582 | count -= 1
|
| 583 |
|
| 584 | chunks.append(value.Str(string[cursor:]))
|
| 585 |
|
| 586 | return value.List(chunks)
|
| 587 |
|
| 588 | raise AssertionError()
|