| 1 | # Data types for the Oils AST, aka "Lossless Syntax Tree".
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| 2 | #
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| 3 | # Invariant: the source text can be reconstructed byte-for-byte from this tree.
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| 4 | # The test/lossless.sh suite verifies this.
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| 5 |
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| 6 | # We usually try to preserve the physical order of the source in the ASDL
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| 7 | # fields. One exception is the order of redirects:
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| 8 | #
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| 9 | # echo >out.txt hi
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| 10 | # # versus
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| 11 | # echo hi >out.txt
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| 12 |
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| 13 | # Unrepresented:
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| 14 | # - let arithmetic (rarely used)
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| 15 | # - coprocesses # one with arg and one without
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| 16 | # - select block
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| 17 |
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| 18 | # Possible refactorings:
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| 19 | #
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| 20 | # # %CompoundWord as first class variant:
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| 21 | # bool_expr = WordTest %CompoundWord | ...
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| 22 | #
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| 23 | # # Can DoubleQuoted have a subset of parts compared with CompoundWord?
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| 24 | # string_part = ... # subset of word_part
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| 25 | #
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| 26 | # - Distinguish word_t with BracedTree vs. those without? seq_word_t?
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| 27 |
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| 28 | module syntax
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| 29 | {
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| 30 | use core value {
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| 31 | value LiteralBlock
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| 32 | }
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| 33 |
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| 34 | # More efficient than the List[bool] pattern we've been using
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| 35 | BoolParamBox = (bool b)
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| 36 | IntParamBox = (int i)
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| 37 |
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| 38 | # core/main_loop.py
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| 39 | parse_result = EmptyLine | Eof | Node(command cmd)
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| 40 |
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| 41 | # 'source' represents the location of a line / token.
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| 42 | source =
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| 43 | Interactive
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| 44 | | Headless
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| 45 | | Unused(str comment) # completion and history never show parse errors?
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| 46 | | CFlag
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| 47 | | Stdin(str comment)
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| 48 |
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| 49 | # MainFile is for main.{osh,ysh}, --eval oshrc/yshrc. They're files loaded
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| 50 | # directly by the shell.
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| 51 | | MainFile(str path)
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| 52 | # A file loaded by 'source' or 'use'.
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| 53 | # TODO: we probably don't need this location? The debug stack provides a
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| 54 | # chain of locations back to the sourced script. Maybe we need to point to
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| 55 | # a debug_frame instead?
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| 56 | # It could be DiskFileShell and DiskFileUser, or just DiskFile.
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| 57 | | OtherFile(str path, loc location)
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| 58 |
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| 59 | # Code parsed from a word. (TODO: rename source.Word?)
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| 60 | # used for 'eval arg', 'trap arg', 'printf arg',
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| 61 | # parseCommand() - this is a string?
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| 62 | # dynamic LHS - move this to Reparsed?
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| 63 | # complete -W
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| 64 | | Dynamic(str what, loc location)
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| 65 |
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| 66 | # Point to the original variable reference
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| 67 | | VarRef(Token orig_tok)
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| 68 |
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| 69 | # code parsed from the value of a variable
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| 70 | # used for $PS1 $PROMPT_COMMAND
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| 71 | | Variable(str var_name, loc location)
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| 72 |
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| 73 | # alias expansion (location of first word)
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| 74 | | Alias(str argv0, loc argv0_loc)
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| 75 |
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| 76 | # 2 kinds of reparsing: backticks, and x+1 in a[x+1]=y
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| 77 | | Reparsed(str what, Token left_token, Token right_token)
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| 78 |
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| 79 | # For --location-str
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| 80 | | Synthetic(str s)
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| 81 |
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| 82 | SourceLine = (int line_num, str content, source src)
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| 83 |
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| 84 | # Note that ASDL generates:
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| 85 | # typedef uint16_t Id_t;
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| 86 | # So Token is
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| 87 | # 8 bytes GC header + 2 + 2 + 4 + 8 + 8 = 32 bytes on 64-bit machines
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| 88 | #
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| 89 | # We transpose (id, col, length) -> (id, length, col) for C struct packing.
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| 90 | Token = (id id, uint16 length, int col, SourceLine? line, str? tval)
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| 91 |
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| 92 | # I wanted to get rid of Token.tval with this separate WideToken type, but it
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| 93 | # is more efficient if word_part.Literal %Token literally is the same thing
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| 94 | # that comes out of the lexer. Otherwise we have extra garbage.
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| 95 |
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| 96 | # WideToken = (id id, int length, int col, SourceLine? line, str? tval)
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| 97 |
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| 98 | # Slight ASDL bug: CompoundWord has to be defined before using it as a shared
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| 99 | # variant. The _product_counter algorithm should be moved into a separate
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| 100 | # tag-assigning pass, and shared between gen_python.py and gen_cpp.py.
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| 101 | CompoundWord = (List[word_part] parts)
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| 102 |
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| 103 | # Source location for errors
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| 104 | loc =
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| 105 | Missing # equivalent of runtime.NO_SPID
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| 106 | | Token %Token
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| 107 | # Very common case: argv arrays need original location
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| 108 | | ArgWord %CompoundWord
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| 109 | | WordPart(word_part p)
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| 110 | | Word(word w)
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| 111 | | Arith(arith_expr a)
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| 112 | # e.g. for errexit blaming
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| 113 | | Command(command c)
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| 114 | # the location of a token that's too long
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| 115 | | TokenTooLong(SourceLine line, id id, int length, int col)
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| 116 |
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| 117 | # debug_frame_t is an EXECUTION stack (proc func source use eval), while
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| 118 | # source_t (in some cases) is like a PARSING stack (files, strings from vars,
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| 119 | # etc.)
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| 120 | debug_frame =
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| 121 | # OSH: main_filename => BASH_SOURCE
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| 122 | MainFile(str main_filename)
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| 123 | # YSH
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| 124 | | Dummy # -c or stdin, not used by BASH_* vars
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| 125 | # Note: we could have more "frame 0" than MainFile and Dummy -
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| 126 | # - Completion hooks - dev.Tracer is missing these
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| 127 | # - PS1
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| 128 | # - PROMPT_COMMAND
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| 129 |
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| 130 | # OSH: call_tok => BASH_LINENO, source_name => BASH_SOURCE
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| 131 | | Source(CompoundWord source_loc, str source_name)
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| 132 |
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| 133 | # OSH: call_tok => BASH_LINENO, def_tok => BASH_SOURCE
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| 134 | # YSH: procs
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| 135 | | ProcLike(CompoundWord invoke_loc, Token def_tok, str proc_name)
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| 136 |
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| 137 | # for io->eval, myfunc()
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| 138 | | Token %Token
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| 139 |
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| 140 | # For 'eval', 'use', ...
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| 141 | | CompoundWord %CompoundWord
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| 142 |
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| 143 | # Special frame added when running 'trap ERR', for more info, and as a sentinel
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| 144 | | BeforeErrTrap(Token tok)
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| 145 |
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| 146 | #
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| 147 | # Shell language
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| 148 | #
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| 149 |
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| 150 | bracket_op =
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| 151 | WholeArray(id op_id) # * or @
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| 152 | | ArrayIndex(arith_expr expr)
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| 153 |
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| 154 | suffix_op =
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| 155 | Nullary %Token # ${x@Q} or ${!prefix@} (which also has prefix_op)
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| 156 | | Unary(Token op, rhs_word arg_word) # e.g. ${v:-default}
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| 157 | # TODO: Implement YSH ${x|html} and ${x %.3f}
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| 158 | | Static(Token tok, str arg)
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| 159 | | PatSub(CompoundWord pat, rhs_word replace, id replace_mode, Token slash_tok)
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| 160 | # optional begin is arith_expr.EmptyZero
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| 161 | # optional length is None, because it's handled in a special way
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| 162 | | Slice(arith_expr begin, arith_expr? length)
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| 163 |
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| 164 | BracedVarSub = (
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| 165 | Token left, # in dynamic ParseVarRef, same as name_tok
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| 166 | Token name_tok, # location for the name
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| 167 | str var_name, # the name - TODO: remove this, use LazyStr() instead
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| 168 | Token? prefix_op, # prefix # or ! operators
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| 169 | bracket_op? bracket_op,
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| 170 | suffix_op? suffix_op,
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| 171 | Token right # in dynamic ParseVarRef, same as name_tok
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| 172 | )
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| 173 |
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| 174 | # Variants:
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| 175 | # - Look at left token ID for $'' c'' vs r'' '' e.g. Id.Left_DollarSingleQuote
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| 176 | # - And """ and ''' e.g. Id.Left_TDoubleQuote
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| 177 | DoubleQuoted = (Token left, List[word_part] parts, Token right)
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| 178 |
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| 179 | # Consider making str? sval LAZY, like lexer.LazyStr(tok)
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| 180 | SingleQuoted = (Token left, str sval, Token right)
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| 181 |
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| 182 | # e.g. Id.VSub_QMark, Id.VSub_DollarName $foo with lexer.LazyStr()
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| 183 | SimpleVarSub = (Token tok)
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| 184 |
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| 185 | CommandSub = (Token left_token, command child, Token right)
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| 186 |
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| 187 | # - can contain word.BracedTree
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| 188 | # - no 'Token right' for now, doesn't appear to be used
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| 189 | YshArrayLiteral = (Token left, List[word] words, Token right)
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| 190 |
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| 191 | # Unevaluated, typed arguments for func and proc.
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| 192 | # Note that ...arg is expr.Spread.
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| 193 | ArgList = (
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| 194 | Token left, List[expr] pos_args,
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| 195 | Token? semi_tok, List[NamedArg] named_args,
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| 196 | Token? semi_tok2, expr? block_expr,
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| 197 | Token right
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| 198 | )
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| 199 |
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| 200 | AssocPair = (CompoundWord key, CompoundWord value, bool has_plus)
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| 201 |
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| 202 | InitializerWord =
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| 203 | ArrayWord(word w)
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| 204 | | AssocPair %AssocPair
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| 205 |
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| 206 | word_part =
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| 207 | YshArrayLiteral %YshArrayLiteral
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| 208 | | InitializerLiteral(Token left, List[InitializerWord] pairs, Token right)
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| 209 | | Literal %Token
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| 210 | # escaped case is separate so the evaluator doesn't have to check token ID
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| 211 | | EscapedLiteral(Token token, str ch)
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| 212 | | SingleQuoted %SingleQuoted
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| 213 | | DoubleQuoted %DoubleQuoted
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| 214 | # Could be SimpleVarSub %Token that's VSub_DollarName, but let's not
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| 215 | # confuse with the comon word_part.Literal is common for wno
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| 216 | | SimpleVarSub %SimpleVarSub
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| 217 | | BracedVarSub %BracedVarSub
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| 218 | | ZshVarSub (Token left, CompoundWord ignored, Token right)
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| 219 | # For command sub and process sub: $(...) <(...) >(...)
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| 220 | | CommandSub %CommandSub
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| 221 | # ~ or ~bob
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| 222 | | TildeSub(Token left, # always the tilde
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| 223 | Token? name, str? user_name)
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| 224 | | ArithSub(Token left, arith_expr anode, Token right)
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| 225 | # {a,b,c}
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| 226 | | BracedTuple(List[CompoundWord] words)
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| 227 | # {1..10} or {-5..10..2} or {01..10} (leading zeros matter)
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| 228 | # {a..f} or {a..f..2} or {a..f..-2}
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| 229 | # the whole range is one Token,
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| 230 | | BracedRange(Token blame_tok, id kind, str start, str end, int step)
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| 231 | # expanded version of {1..10}
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| 232 | | BracedRangeDigit(str s, Token orig_tok)
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| 233 | # extended globs are parsed statically, unlike globs
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| 234 | | ExtGlob(Token op, List[CompoundWord] arms, Token right)
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| 235 | # a regex group is similar to an extended glob part
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| 236 | | BashRegexGroup(Token left, CompoundWord? child, Token right)
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| 237 |
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| 238 | # YSH word_part extensions
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| 239 |
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| 240 | # @myarray - Id.Lit_Splice (could be optimized to %Token)
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| 241 | | Splice(Token blame_tok, str var_name)
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| 242 | # $[d.key], etc.
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| 243 | | ExprSub(Token left, expr child, Token right)
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| 244 |
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| 245 | # Use cases for Empty: RHS of 'x=', the argument in "${x:-}".
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| 246 | # The latter is semantically necessary. (See osh/word_parse.py).
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| 247 | # At runtime: RHS of 'declare x='.
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| 248 | rhs_word = Empty | Compound %CompoundWord
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| 249 |
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| 250 | word =
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| 251 | # Returns from WordParser, but not generally stored in LST
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| 252 | Operator %Token
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| 253 | # A Compound word can contain any word_part except the Braced*Part.
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| 254 | # We could model this with another variant type but it incurs runtime
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| 255 | # overhead and seems like overkill. Note that DoubleQuoted can't
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| 256 | # contain a SingleQuoted, etc. either.
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| 257 | | Compound %CompoundWord
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| 258 | # For word sequences command.Simple, YshArrayLiteral, for_iter.Words
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| 259 | # Could be its own type
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| 260 | | BracedTree(List[word_part] parts)
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| 261 | # For dynamic parsing of test aka [ - the string is already evaluated.
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| 262 | | String(id id, str s, CompoundWord? blame_loc)
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| 263 |
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| 264 | # Note: the name 'foo' is derived from token value 'foo=' or 'foo+='
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| 265 | sh_lhs =
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| 266 | Name(Token left, str name) # Lit_VarLike foo=
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| 267 | # TODO: Could be Name %Token
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| 268 | | IndexedName(Token left, str name, arith_expr index)
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| 269 | | UnparsedIndex(Token left, str name, str index) # for translation
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| 270 |
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| 271 | arith_expr =
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| 272 | EmptyZero # these are valid: $(( )) (( )) ${a[@]: : }
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| 273 | | EmptyOne # condition is 1 for infinite loop: for (( ; ; ))
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| 274 | | VarSub %Token # e.g. $(( x )) Id.Arith_VarLike
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| 275 | | Word %CompoundWord # e.g. $(( 123'456'$y ))
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| 276 |
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| 277 | | UnaryAssign(id op_id, arith_expr child)
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| 278 | | BinaryAssign(id op_id, arith_expr left, arith_expr right)
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| 279 |
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| 280 | | Unary(id op_id, arith_expr child)
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| 281 | | Binary(Token op, arith_expr left, arith_expr right)
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| 282 | | TernaryOp(arith_expr cond, arith_expr true_expr, arith_expr false_expr)
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| 283 |
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| 284 | bool_expr =
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| 285 | WordTest(word w) # e.g. [[ myword ]]
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| 286 | | Binary(id op_id, word left, word right)
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| 287 | | Unary(id op_id, word child)
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| 288 | | LogicalNot(bool_expr child)
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| 289 | | LogicalAnd(bool_expr left, bool_expr right)
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| 290 | | LogicalOr(bool_expr left, bool_expr right)
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| 291 |
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| 292 | redir_loc =
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| 293 | Fd(int fd) | VarName(str name)
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| 294 |
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| 295 | redir_param =
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| 296 | Word %CompoundWord
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| 297 | | HereWord(CompoundWord w, bool is_multiline)
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| 298 | | HereDoc(word here_begin, # e.g. EOF or 'EOF'
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| 299 | Token? here_end_tok, # Token consisting of the whole line
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| 300 | # It's always filled in AFTER creation, but
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| 301 | # temporarily so optional
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| 302 | List[word_part] stdin_parts # one for each line
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| 303 | )
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| 304 |
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| 305 | Redir = (Token op, redir_loc loc, redir_param arg)
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| 306 |
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| 307 | assign_op = Equal | PlusEqual
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| 308 | AssignPair = (Token left, sh_lhs lhs, assign_op op, rhs_word rhs)
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| 309 | # TODO: could put Id.Lit_VarLike foo= into LazyStr() with -1 slice
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| 310 | EnvPair = (Token left, str name, rhs_word val)
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| 311 |
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| 312 | List_of_command < List[command]
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| 313 |
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| 314 | condition =
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| 315 | Shell %List_of_command # if false; true; then echo hi; fi
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| 316 | | YshExpr(expr e) # if (x > 0) { echo hi }
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| 317 | # TODO: add more specific blame location
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| 318 |
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| 319 | # Each arm tests one word against multiple words
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| 320 | # shell: *.cc|*.h) echo C++ ;;
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| 321 | # YSH: *.cc|*.h { echo C++ }
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| 322 | #
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| 323 | # Three location tokens:
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| 324 | # 1. left - shell has ( or *.cc ysh has *.cc
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| 325 | # 2. middle - shell has ) ysh has {
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| 326 | # 3. right - shell has optional ;; ysh has required }
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| 327 | #
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| 328 | # For YSH typed case, left can be ( and /
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| 329 | # And case_pat may contain more details
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| 330 | CaseArm = (
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| 331 | Token left, pat pattern, Token middle, List[command] action,
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| 332 | Token? right
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| 333 | )
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| 334 |
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| 335 | # The argument to match against in a case command
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| 336 | # In YSH-style case commands we match against an `expr`, but in sh-style case
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| 337 | # commands we match against a word.
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| 338 | case_arg =
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| 339 | Word(word w)
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| 340 | | YshExpr(expr e)
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| 341 |
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| 342 | EggexFlag = (bool negated, Token flag)
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| 343 |
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| 344 | # canonical_flags can be compared for equality. This is needed to splice
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| 345 | # eggexes correctly, e.g. / 'abc' @pat ; i /
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| 346 | Eggex = (
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| 347 | Token left, re regex, List[EggexFlag] flags, Token? trans_pref,
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| 348 | str? canonical_flags)
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| 349 |
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| 350 | pat =
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| 351 | Else
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| 352 | | Words(List[word] words)
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| 353 | | YshExprs(List[expr] exprs)
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| 354 | | Eggex %Eggex
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| 355 |
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| 356 | # Each if arm starts with either an "if" or "elif" keyword
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| 357 | # In YSH, the then keyword is not used (replaced by braces {})
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| 358 | IfArm = (
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| 359 | Token keyword, condition cond, Token? then_kw, List[command] action,
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| 360 | # then_tok used in ysh-ify
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| 361 | Token? then_tok)
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| 362 |
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| 363 | for_iter =
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| 364 | Args # for x; do echo $x; done # implicit "$@"
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| 365 | | Words(List[word] words) # for x in 'foo' *.py { echo $x }
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| 366 | # like YshArrayLiteral, but no location for %(
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| 367 | | YshExpr(expr e, Token blame) # for x in (mylist) { echo $x }
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| 368 | #| Files(Token left, List[word] words)
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| 369 | # for x in <> {
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| 370 | # for x in < @myfiles > {
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| 371 |
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| 372 | BraceGroup = (
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| 373 | Token left, Token? doc_token, List[command] children, Token right
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| 374 | )
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| 375 |
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| 376 | Param = (Token blame_tok, str name, TypeExpr? type, expr? default_val)
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| 377 | RestParam = (Token blame_tok, str name)
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| 378 |
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| 379 | ParamGroup = (List[Param] params, RestParam? rest_of)
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| 380 |
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| 381 | # 'open' is for proc p { }; closed is for proc p () { }
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| 382 | proc_sig =
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| 383 | Open
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| 384 | | Closed(ParamGroup? word, ParamGroup? positional, ParamGroup? named,
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| 385 | Param? block_param)
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| 386 |
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| 387 | Proc = (Token keyword, Token name, proc_sig sig, command body)
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| 388 |
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| 389 | Func = (
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| 390 | Token keyword, Token name,
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| 391 | ParamGroup? positional, ParamGroup? named,
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| 392 | command body
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| 393 | )
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| 394 |
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| 395 | # Represents all these case: s=1 s+=1 s[x]=1 ...
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| 396 | ParsedAssignment = (Token? left, Token? close, int part_offset, CompoundWord w)
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| 397 |
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| 398 | # var, const.
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| 399 | # - Keyword is None for hay blocks. TODO: consider using BareDecl?
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| 400 | # - 'var x' allowed - RHS is None; idiomatic with value.Place
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| 401 | VarDecl = (Token? keyword, List[NameType] lhs, expr? rhs)
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| 402 |
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| 403 | # setvar, maybe 'auto' later
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| 404 | Mutation = (Token keyword, List[y_lhs] lhs, Token op, expr rhs)
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| 405 |
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| 406 | # call f(x) = 42
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| 407 | ExprCommand = (Token keyword, expr e)
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| 408 |
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| 409 | ShFunction = (
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| 410 | Token? keyword, Token name_tok, str name, command body,
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| 411 | str? code_str
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| 412 | )
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| 413 |
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| 414 | command =
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| 415 | NoOp
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| 416 |
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| 417 | # can wrap many children, e.g. { }, loops, functions
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| 418 | | Redirect(command child, List[Redir] redirects)
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| 419 |
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| 420 | | Simple(Token? blame_tok, # TODO: make required (BracedTuple?)
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| 421 | List[EnvPair] more_env,
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| 422 | List[word] words,
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| 423 | ArgList? typed_args, LiteralBlock? block,
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| 424 | # is_last_cmd is used for fork() optimizations
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| 425 | bool is_last_cmd)
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| 426 |
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| 427 | # This doesn't technically belong in the LST, but it's convenient for
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| 428 | # execution
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| 429 | | ExpandedAlias(command child, List[EnvPair] more_env)
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| 430 | | Sentence(command child, Token terminator)
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| 431 | # Represents "bare assignment"
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| 432 | # Token left is redundant with pairs[0].left
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| 433 | | ShAssignment(Token left, List[AssignPair] pairs)
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| 434 |
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| 435 | | ControlFlow(Token keyword, CompoundWord? arg_word)
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| 436 |
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| 437 | # ops are | |&
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| 438 | | Pipeline(Token? negated, List[command] children, List[Token] ops)
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| 439 | # ops are && ||
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| 440 | | AndOr(List[command] children, List[Token] ops)
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| 441 |
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| 442 | # Part of for, while, until (but not if, case, ShFunction). No redirects.
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| 443 | | DoGroup(Token left, List[command] children, Token right)
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| 444 | # A brace group is a compound command, with redirects.
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| 445 | | BraceGroup %BraceGroup
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| 446 | # Contains a single child, like CommandSub
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| 447 | | Subshell(Token left, command child, Token right, bool is_last_cmd)
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| 448 | | DParen(Token left, arith_expr child, Token right)
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| 449 | | DBracket(Token left, bool_expr expr, Token right)
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| 450 |
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| 451 | # up to 3 iterations variables
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| 452 | | ForEach(Token keyword, List[str] iter_names, for_iter iterable,
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| 453 | Token? semi_tok, command body)
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| 454 | # C-style for loop. Any of the 3 expressions can be omitted.
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| 455 | # Note: body is required, but only optional here because of initialization
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| 456 | # order.
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| 457 | | ForExpr(Token keyword, arith_expr? init, arith_expr? cond,
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| 458 | arith_expr? update, command? body)
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| 459 | | WhileUntil(Token keyword, condition cond, command body)
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| 460 |
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| 461 | | If(Token if_kw, List[IfArm] arms, Token? else_kw, List[command] else_action,
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| 462 | Token? fi_kw)
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| 463 | | Case(Token case_kw, case_arg to_match, Token arms_start, List[CaseArm] arms,
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| 464 | Token arms_end)
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| 465 |
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| 466 | # The keyword is optional in the case of bash-style functions
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| 467 | # (ie. "foo() { ... }") which do not have one.
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| 468 | | ShFunction %ShFunction
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| 469 |
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| 470 | | TimeBlock(Token keyword, command pipeline)
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| 471 | # Some nodes optimize it out as List[command], but we use CommandList for
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| 472 | # 1. the top level
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| 473 | # 2. ls ; ls & ls (same line)
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| 474 | # 3. CommandSub # single child that's a CommandList
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| 475 | # 4. Subshell # single child that's a CommandList
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| 476 |
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| 477 | # TODO: Use List_of_command
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| 478 | | CommandList(List[command] children)
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| 479 |
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| 480 | # YSH command constructs
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| 481 |
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| 482 | | VarDecl %VarDecl
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| 483 |
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| 484 | # this can behave like 'var', can be desugared
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| 485 | | BareDecl(Token lhs, expr rhs)
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| 486 |
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| 487 | | Mutation %Mutation
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| 488 | | Expr %ExprCommand
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| 489 | | Proc %Proc
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| 490 | | Func %Func
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| 491 | | Retval(Token keyword, expr val)
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| 492 |
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| 493 | # bytecode
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| 494 | b_command =
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| 495 | VarDecl %VarDecl
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| 496 | | Mutation %Mutation
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| 497 |
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| 498 | #
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| 499 | # Glob representation, for converting ${x//} to extended regexes.
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| 500 | #
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| 501 |
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| 502 | # Example: *.[ch] is:
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| 503 | # GlobOp(<Glob_Star '*'>),
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| 504 | # GlobLit(Glob_OtherLiteral, '.'),
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| 505 | # CharClass(False, ['ch']) # from Glob_CleanLiterals token
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| 506 |
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| 507 | glob_part =
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| 508 | Literal(id id, str s)
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| 509 | | Operator(id op_id) # * or ?
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| 510 | | CharClass(bool negated, List[str] strs)
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| 511 |
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| 512 | # Char classes are opaque for now. If we ever need them:
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| 513 | # - Collating symbols are [. .]
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| 514 | # - Equivalence classes are [=
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| 515 |
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| 516 | printf_part =
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| 517 | Literal %Token
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| 518 | # flags are 0 hyphen space + #
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| 519 | # type is 's' for %s, etc.
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| 520 | | Percent(List[Token] flags, Token? width, Token? precision, Token type)
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| 521 |
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| 522 | #
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| 523 | # YSH Language
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| 524 | #
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| 525 | # Copied and modified from Python-3.7/Parser/Python.asdl !
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| 526 |
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| 527 | expr_context = Load | Store | Del | AugLoad | AugStore | Param
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| 528 |
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| 529 | # Type expressions: Int List[Int] Dict[Str, Any]
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| 530 | # Do we have Func[Int, Int => Int] ? I guess we can parse that into this
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| 531 | # system.
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| 532 | TypeExpr = (Token tok, str name, List[TypeExpr] params)
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| 533 |
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| 534 | # LHS bindings in var/const, and eggex
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| 535 | NameType = (Token left, str name, TypeExpr? typ)
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| 536 |
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| 537 | # TODO: Inline this into GenExp and ListComp? Just use a flag there?
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| 538 | Comprehension = (List[NameType] lhs, expr iter, expr? cond)
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| 539 |
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| 540 | # Named arguments supplied to call. Token is null for f(; ...named).
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| 541 | NamedArg = (Token? name, expr value)
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| 542 |
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| 543 | # Subscripts are lists of expressions
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| 544 | # a[:i, n] (we don't have matrices, but we have data frames)
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| 545 | Subscript = (Token left, expr obj, expr index)
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| 546 |
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| 547 | # Attributes are obj.attr, d->key, name::scope,
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| 548 | Attribute = (expr obj, Token op, Token attr, str attr_name, expr_context ctx)
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| 549 |
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| 550 | y_lhs =
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| 551 | Var %Token # Id.Expr_Name
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| 552 | | Subscript %Subscript
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| 553 | | Attribute %Attribute
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| 554 |
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| 555 | place_op =
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| 556 | # &a[i+1]
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| 557 | Subscript(Token op, expr index)
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| 558 | # &d.mykey
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| 559 | | Attribute(Token op, Token attr)
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| 560 |
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| 561 | expr =
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| 562 | Var(Token left, str name) # a variable name to evaluate
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| 563 | # Constants are typically Null, Bool, Int, Float
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| 564 | # and also Str for key in {key: 42}
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| 565 | # But string literals are SingleQuoted or DoubleQuoted
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| 566 | # Python uses Num(object n), which doesn't respect our "LST" invariant.
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| 567 | | Const(Token c, value val)
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| 568 |
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| 569 | # read(&x) json read (&x[0])
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| 570 | | Place(Token blame_tok, str var_name, place_op* ops)
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| 571 |
|
| 572 | # :| one 'two' "$three" |
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| 573 | | YshArrayLiteral %YshArrayLiteral
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| 574 |
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| 575 | # / d+ ; ignorecase; %python /
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| 576 | | Eggex %Eggex
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| 577 |
|
| 578 | # $name is not an expr, but $? is, e.g. Id.VSub_QMark
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| 579 | | SimpleVarSub %SimpleVarSub
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| 580 | | BracedVarSub %BracedVarSub
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| 581 | | CommandSub %CommandSub
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| 582 | | SingleQuoted %SingleQuoted
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| 583 | | DoubleQuoted %DoubleQuoted
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| 584 |
|
| 585 | | Literal(expr inner)
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| 586 | | Lambda(List[NameType] params, expr body)
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| 587 |
|
| 588 | | Unary(Token op, expr child)
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| 589 | | Binary(Token op, expr left, expr right)
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| 590 | # x < 4 < 3 and (x < 4) < 3
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| 591 | | Compare(expr left, List[Token] ops, List[expr] comparators)
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| 592 | | FuncCall(expr func, ArgList args)
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| 593 |
|
| 594 | # TODO: Need a representation for method call. We don't just want
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| 595 | # Attribute() and then Call()
|
| 596 |
|
| 597 | | IfExp(expr test, expr body, expr orelse)
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| 598 | | Tuple(Token left, List[expr] elts, expr_context ctx)
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| 599 |
|
| 600 | | List(Token left, List[expr] elts, expr_context ctx)
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| 601 | | Dict(Token left, List[expr] keys, List[expr] values)
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| 602 | # For the values in {n1, n2}
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| 603 | | Implicit
|
| 604 |
|
| 605 | | ListComp(Token left, expr elt, List[Comprehension] generators)
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| 606 | # not implemented
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| 607 | | DictComp(Token left, expr key, expr value, List[Comprehension] generators)
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| 608 | | GeneratorExp(expr elt, List[Comprehension] generators)
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| 609 |
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| 610 | # Ranges are written 1:2, with first class expression syntax. There is no
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| 611 | # step as in Python. Use range(0, 10, step=2) for that.
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| 612 | | Range(expr lower, Token op, expr upper)
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| 613 |
|
| 614 | # Slices occur within [] only. Unlike ranges, the start/end can be #
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| 615 | # implicit. Like ranges, denote a step with slice(0, 10, step=2).
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| 616 | # a[3:] a[:i]
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| 617 | | Slice(expr? lower, Token op, expr? upper)
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| 618 |
|
| 619 | | Subscript %Subscript
|
| 620 | | Attribute %Attribute
|
| 621 |
|
| 622 | # Ellipsis is like 'Starred' within Python, which are valid on the LHS in
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| 623 | # Python for unpacking, and # within list literals for splicing.
|
| 624 | # (Starred is NOT used for {k:v, **a}. That used a blank "keys"
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| 625 | # attribute.)
|
| 626 |
|
| 627 | # I think we can use { **pairs } like Python
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| 628 | | Spread(Token left, expr child)
|
| 629 |
|
| 630 | #
|
| 631 | # Regex Language (Eggex)
|
| 632 | #
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| 633 |
|
| 634 | # e.g. alnum digit
|
| 635 | PosixClass = (Token? negated, str name)
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| 636 | # e.g. d w s
|
| 637 | PerlClass = (Token? negated, str name)
|
| 638 |
|
| 639 | # Char Sets and Ranges both use Char Codes
|
| 640 | # with u_braced == true : \u{ff}
|
| 641 | # with u_braced == false: \xff \\ 'a' a '0' 0
|
| 642 | # ERE doesn't make a distinction, but compiling to Python/PCRE can use it
|
| 643 | CharCode = (Token blame_tok, int i, bool u_braced)
|
| 644 | CharRange = (CharCode start, CharCode end)
|
| 645 |
|
| 646 | # Note: .NET has && in character classes, making it a recursive language
|
| 647 |
|
| 648 | class_literal_term =
|
| 649 | PosixClass %PosixClass
|
| 650 | | PerlClass %PerlClass
|
| 651 | | CharRange %CharRange
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| 652 | | CharCode %CharCode
|
| 653 |
|
| 654 | | SingleQuoted %SingleQuoted
|
| 655 | # @chars
|
| 656 | | Splice(Token name, str var_name) # coudl be Splice %Token
|
| 657 |
|
| 658 | # evaluated version of class_literal_term (could be in runtime.asdl)
|
| 659 | char_class_term =
|
| 660 | PosixClass %PosixClass
|
| 661 | | PerlClass %PerlClass
|
| 662 |
|
| 663 | | CharRange %CharRange
|
| 664 | # For [ \x00 \\ ]
|
| 665 | | CharCode %CharCode
|
| 666 |
|
| 667 | # NOTE: modifier is unused now, can represent L or P
|
| 668 | re_repeat =
|
| 669 | Op %Token # + * ? or Expr_DecInt for x{3}
|
| 670 | | Range(Token? left, str lower, str upper, Token? right) # dot{1,2}
|
| 671 | # Haven't implemented the modifier, e.g. x{+ P}
|
| 672 | # | Num(Token times, id modifier)
|
| 673 | # | Range(Token? lower, Token? upper, id modifier)
|
| 674 |
|
| 675 | re =
|
| 676 | Primitive(Token blame_tok, id id) # . ^ $ dot %start %end
|
| 677 | | PosixClass %PosixClass
|
| 678 | | PerlClass %PerlClass
|
| 679 | # syntax [ $x \n ]
|
| 680 | | CharClassLiteral(bool negated, List[class_literal_term] terms)
|
| 681 | # evaluated [ 'abc' \n ]
|
| 682 | | CharClass(bool negated, List[char_class_term] terms)
|
| 683 |
|
| 684 | # @D
|
| 685 | | Splice(Token name, str var_name) # TODO: Splice %Token ?
|
| 686 |
|
| 687 | | SingleQuoted %SingleQuoted
|
| 688 |
|
| 689 | # Compound:
|
| 690 | | Repeat(re child, re_repeat op)
|
| 691 | | Seq(List[re] children)
|
| 692 | | Alt(List[re] children)
|
| 693 |
|
| 694 | | Group(re child)
|
| 695 | # convert_func is filled in on evaluation
|
| 696 | # TODO: name and func_name can be expanded to strings
|
| 697 | | Capture(re child, Token? name, Token? func_name)
|
| 698 | | Backtracking(bool negated, Token name, re child)
|
| 699 |
|
| 700 | # \u{ff} is parsed as this, but SingleQuoted also evaluates to it
|
| 701 | | LiteralChars(Token blame_tok, str s)
|
| 702 | }
|