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| 1 | +# frozen_string_literal: false |
| 2 | +# |
| 3 | +# irb/slex.rb - simple lex analyzer |
| 4 | +# $Release Version: 0.9.6$ |
| 5 | +# $Revision$ |
| 6 | +# by Keiju ISHITSUKA(keiju@ruby-lang.org) |
| 7 | +# |
| 8 | +# -- |
| 9 | +# |
| 10 | +# |
| 11 | +# |
| 12 | + |
| 13 | +require "e2mmap" |
| 14 | +require "irb/notifier" |
| 15 | + |
| 16 | +# :stopdoc: |
| 17 | +module IRB |
| 18 | + class SLex |
| 19 | + |
| 20 | + extend Exception2MessageMapper |
| 21 | + def_exception :ErrNodeNothing, "node nothing" |
| 22 | + def_exception :ErrNodeAlreadyExists, "node already exists" |
| 23 | + |
| 24 | + DOUT = Notifier::def_notifier("SLex::") |
| 25 | + D_WARN = DOUT::def_notifier(1, "Warn: ") |
| 26 | + D_DEBUG = DOUT::def_notifier(2, "Debug: ") |
| 27 | + D_DETAIL = DOUT::def_notifier(4, "Detail: ") |
| 28 | + |
| 29 | + DOUT.level = Notifier::D_NOMSG |
| 30 | + |
| 31 | + def initialize |
| 32 | + @head = Node.new("") |
| 33 | + end |
| 34 | + |
| 35 | + def def_rule(token, preproc = nil, postproc = nil, &block) |
| 36 | + D_DETAIL.pp token |
| 37 | + |
| 38 | + postproc = block if block_given? |
| 39 | + create(token, preproc, postproc) |
| 40 | + end |
| 41 | + |
| 42 | + def def_rules(*tokens, &block) |
| 43 | + if block_given? |
| 44 | + p = block |
| 45 | + end |
| 46 | + for token in tokens |
| 47 | + def_rule(token, nil, p) |
| 48 | + end |
| 49 | + end |
| 50 | + |
| 51 | + def preproc(token, proc) |
| 52 | + node = search(token) |
| 53 | + node.preproc=proc |
| 54 | + end |
| 55 | + |
| 56 | + # need a check? |
| 57 | + def postproc(token) |
| 58 | + node = search(token, proc) |
| 59 | + node.postproc=proc |
| 60 | + end |
| 61 | + |
| 62 | + def search(token) |
| 63 | + @head.search(token.split(//)) |
| 64 | + end |
| 65 | + |
| 66 | + def create(token, preproc = nil, postproc = nil) |
| 67 | + @head.create_subnode(token.split(//), preproc, postproc) |
| 68 | + end |
| 69 | + |
| 70 | + def match(token) |
| 71 | + case token |
| 72 | + when Array |
| 73 | + when String |
| 74 | + return match(token.split(//)) |
| 75 | + else |
| 76 | + return @head.match_io(token) |
| 77 | + end |
| 78 | + ret = @head.match(token) |
| 79 | + D_DETAIL.exec_if{D_DETAIL.printf "match end: %s:%s\n", ret, token.inspect} |
| 80 | + ret |
| 81 | + end |
| 82 | + |
| 83 | + def inspect |
| 84 | + format("<SLex: @head = %s>", @head.inspect) |
| 85 | + end |
| 86 | + |
| 87 | + #---------------------------------------------------------------------- |
| 88 | + # |
| 89 | + # class Node - |
| 90 | + # |
| 91 | + #---------------------------------------------------------------------- |
| 92 | + class Node |
| 93 | + # if postproc is nil, this node is an abstract node. |
| 94 | + # if postproc is non-nil, this node is a real node. |
| 95 | + def initialize(preproc = nil, postproc = nil) |
| 96 | + @Tree = {} |
| 97 | + @preproc = preproc |
| 98 | + @postproc = postproc |
| 99 | + end |
| 100 | + |
| 101 | + attr_accessor :preproc |
| 102 | + attr_accessor :postproc |
| 103 | + |
| 104 | + def search(chrs, opt = nil) |
| 105 | + return self if chrs.empty? |
| 106 | + ch = chrs.shift |
| 107 | + if node = @Tree[ch] |
| 108 | + node.search(chrs, opt) |
| 109 | + else |
| 110 | + if opt |
| 111 | + chrs.unshift ch |
| 112 | + self.create_subnode(chrs) |
| 113 | + else |
| 114 | + SLex.fail ErrNodeNothing |
| 115 | + end |
| 116 | + end |
| 117 | + end |
| 118 | + |
| 119 | + def create_subnode(chrs, preproc = nil, postproc = nil) |
| 120 | + if chrs.empty? |
| 121 | + if @postproc |
| 122 | + D_DETAIL.pp node |
| 123 | + SLex.fail ErrNodeAlreadyExists |
| 124 | + else |
| 125 | + D_DEBUG.puts "change abstract node to real node." |
| 126 | + @preproc = preproc |
| 127 | + @postproc = postproc |
| 128 | + end |
| 129 | + return self |
| 130 | + end |
| 131 | + |
| 132 | + ch = chrs.shift |
| 133 | + if node = @Tree[ch] |
| 134 | + if chrs.empty? |
| 135 | + if node.postproc |
| 136 | + DebugLogger.pp node |
| 137 | + DebugLogger.pp self |
| 138 | + DebugLogger.pp ch |
| 139 | + DebugLogger.pp chrs |
| 140 | + SLex.fail ErrNodeAlreadyExists |
| 141 | + else |
| 142 | + D_WARN.puts "change abstract node to real node" |
| 143 | + node.preproc = preproc |
| 144 | + node.postproc = postproc |
| 145 | + end |
| 146 | + else |
| 147 | + node.create_subnode(chrs, preproc, postproc) |
| 148 | + end |
| 149 | + else |
| 150 | + if chrs.empty? |
| 151 | + node = Node.new(preproc, postproc) |
| 152 | + else |
| 153 | + node = Node.new |
| 154 | + node.create_subnode(chrs, preproc, postproc) |
| 155 | + end |
| 156 | + @Tree[ch] = node |
| 157 | + end |
| 158 | + node |
| 159 | + end |
| 160 | + |
| 161 | + # |
| 162 | + # chrs: String |
| 163 | + # character array |
| 164 | + # io must have getc()/ungetc(); and ungetc() must be |
| 165 | + # able to be called arbitrary number of times. |
| 166 | + # |
| 167 | + def match(chrs, op = "") |
| 168 | + D_DETAIL.print "match>: ", chrs, "op:", op, "\n" |
| 169 | + if chrs.empty? |
| 170 | + if @preproc.nil? || @preproc.call(op, chrs) |
| 171 | + DOUT.printf(D_DETAIL, "op1: %s\n", op) |
| 172 | + @postproc.call(op, chrs) |
| 173 | + else |
| 174 | + nil |
| 175 | + end |
| 176 | + else |
| 177 | + ch = chrs.shift |
| 178 | + if node = @Tree[ch] |
| 179 | + if ret = node.match(chrs, op+ch) |
| 180 | + return ret |
| 181 | + else |
| 182 | + chrs.unshift ch |
| 183 | + if @postproc and @preproc.nil? || @preproc.call(op, chrs) |
| 184 | + DOUT.printf(D_DETAIL, "op2: %s\n", op.inspect) |
| 185 | + ret = @postproc.call(op, chrs) |
| 186 | + return ret |
| 187 | + else |
| 188 | + return nil |
| 189 | + end |
| 190 | + end |
| 191 | + else |
| 192 | + chrs.unshift ch |
| 193 | + if @postproc and @preproc.nil? || @preproc.call(op, chrs) |
| 194 | + DOUT.printf(D_DETAIL, "op3: %s\n", op) |
| 195 | + @postproc.call(op, chrs) |
| 196 | + return "" |
| 197 | + else |
| 198 | + return nil |
| 199 | + end |
| 200 | + end |
| 201 | + end |
| 202 | + end |
| 203 | + |
| 204 | + def match_io(io, op = "") |
| 205 | + if op == "" |
| 206 | + ch = io.getc |
| 207 | + if ch == nil |
| 208 | + return nil |
| 209 | + end |
| 210 | + else |
| 211 | + ch = io.getc_of_rests |
| 212 | + end |
| 213 | + if ch.nil? |
| 214 | + if @preproc.nil? || @preproc.call(op, io) |
| 215 | + D_DETAIL.printf("op1: %s\n", op) |
| 216 | + @postproc.call(op, io) |
| 217 | + else |
| 218 | + nil |
| 219 | + end |
| 220 | + else |
| 221 | + if node = @Tree[ch] |
| 222 | + if ret = node.match_io(io, op+ch) |
| 223 | + ret |
| 224 | + else |
| 225 | + io.ungetc ch |
| 226 | + if @postproc and @preproc.nil? || @preproc.call(op, io) |
| 227 | + DOUT.exec_if{D_DETAIL.printf "op2: %s\n", op.inspect} |
| 228 | + @postproc.call(op, io) |
| 229 | + else |
| 230 | + nil |
| 231 | + end |
| 232 | + end |
| 233 | + else |
| 234 | + io.ungetc ch |
| 235 | + if @postproc and @preproc.nil? || @preproc.call(op, io) |
| 236 | + D_DETAIL.printf("op3: %s\n", op) |
| 237 | + @postproc.call(op, io) |
| 238 | + else |
| 239 | + nil |
| 240 | + end |
| 241 | + end |
| 242 | + end |
| 243 | + end |
| 244 | + end |
| 245 | + end |
| 246 | +end |
| 247 | +# :startdoc: |
| 248 | + |
| 249 | +if $0 == __FILE__ |
| 250 | + case $1 |
| 251 | + when "1" |
| 252 | + tr = SLex.new |
| 253 | + print "0: ", tr.inspect, "\n" |
| 254 | + tr.def_rule("=") {print "=\n"} |
| 255 | + print "1: ", tr.inspect, "\n" |
| 256 | + tr.def_rule("==") {print "==\n"} |
| 257 | + print "2: ", tr.inspect, "\n" |
| 258 | + |
| 259 | + print "case 1:\n" |
| 260 | + print tr.match("="), "\n" |
| 261 | + print "case 2:\n" |
| 262 | + print tr.match("=="), "\n" |
| 263 | + print "case 3:\n" |
| 264 | + print tr.match("=>"), "\n" |
| 265 | + |
| 266 | + when "2" |
| 267 | + tr = SLex.new |
| 268 | + print "0: ", tr.inspect, "\n" |
| 269 | + tr.def_rule("=") {print "=\n"} |
| 270 | + print "1: ", tr.inspect, "\n" |
| 271 | + tr.def_rule("==", proc{false}) {print "==\n"} |
| 272 | + print "2: ", tr.inspect, "\n" |
| 273 | + |
| 274 | + print "case 1:\n" |
| 275 | + print tr.match("="), "\n" |
| 276 | + print "case 2:\n" |
| 277 | + print tr.match("=="), "\n" |
| 278 | + print "case 3:\n" |
| 279 | + print tr.match("=>"), "\n" |
| 280 | + end |
| 281 | + exit |
| 282 | +end |
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