Remove .pl extension from strelnokoff script.
--HG--
rename : script/strelnokoff.pl => script/strelnokoff
Cat's Eye Technologies
11 years ago
| 0 | #!/usr/local/bin/perl -w | |
| 1 | ||
| 2 | # strelnokoff.pl - Cat's Eye Technologies' Strelnokoff Interpreter | |
| 3 | # v2001.03.24 Chris Pressey, Cat's Eye Technologies | |
| 4 | ||
| 5 | # Copyright (c)2001, Cat's Eye Technologies. | |
| 6 | # All rights reserved. | |
| 7 | # | |
| 8 | # Redistribution and use in source and binary forms, with or without | |
| 9 | # modification, are permitted provided that the following conditions | |
| 10 | # are met: | |
| 11 | # | |
| 12 | # Redistributions of source code must retain the above copyright | |
| 13 | # notice, this list of conditions and the following disclaimer. | |
| 14 | # | |
| 15 | # Redistributions in binary form must reproduce the above copyright | |
| 16 | # notice, this list of conditions and the following disclaimer in | |
| 17 | # the documentation and/or other materials provided with the | |
| 18 | # distribution. | |
| 19 | # | |
| 20 | # Neither the name of Cat's Eye Technologies nor the names of its | |
| 21 | # contributors may be used to endorse or promote products derived | |
| 22 | # from this software without specific prior written permission. | |
| 23 | # | |
| 24 | # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND | |
| 25 | # CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
| 26 | # INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
| 27 | # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 28 | # DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE | |
| 29 | # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, | |
| 30 | # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
| 31 | # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, | |
| 32 | # OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | |
| 33 | # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
| 34 | # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 35 | # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 36 | # POSSIBILITY OF SUCH DAMAGE. | |
| 37 | ||
| 38 | # USAGE: [perl] strelnokoff[.pl] program.skf | |
| 39 | ||
| 40 | ### BEGIN strelnokoff.pl ### | |
| 41 | ||
| 42 | ### SCANNER ### | |
| 43 | ||
| 44 | $program = ''; | |
| 45 | $token = ''; | |
| 46 | sub scan | |
| 47 | { | |
| 48 | if ($program =~ /^\s+/) | |
| 49 | { | |
| 50 | $program = $'; | |
| 51 | goto &scan; | |
| 52 | } | |
| 53 | if ($program =~ /^REM.*?\n/) | |
| 54 | { | |
| 55 | $program = $'; | |
| 56 | goto &scan; | |
| 57 | } | |
| 58 | if ($program =~ /^(\d+)/) | |
| 59 | { | |
| 60 | $token = $1; | |
| 61 | $program = $'; | |
| 62 | } | |
| 63 | elsif ($program =~ /^([A-Za-z_][A-Za-z0-9_]*)/) | |
| 64 | { | |
| 65 | $token = $1; | |
| 66 | $program = $'; | |
| 67 | } | |
| 68 | elsif ($program =~ /^(\'.\')/) | |
| 69 | { | |
| 70 | $token = $1; | |
| 71 | $program = $'; | |
| 72 | } | |
| 73 | elsif ($program =~ /^(.)/) | |
| 74 | { | |
| 75 | $token = $1; | |
| 76 | $program = $'; | |
| 77 | } | |
| 78 | else | |
| 79 | { | |
| 80 | # end of program | |
| 81 | $token = ''; | |
| 82 | $program = ''; | |
| 83 | } | |
| 84 | # print "Scanned: $token\n"; | |
| 85 | } | |
| 86 | ||
| 87 | sub expect | |
| 88 | { | |
| 89 | my $expected = shift; | |
| 90 | if ($token eq $expected) | |
| 91 | { | |
| 92 | scan(); | |
| 93 | } else | |
| 94 | { | |
| 95 | error("Expected '$expected' not '$token'"); | |
| 96 | } | |
| 97 | } | |
| 98 | ||
| 99 | sub error | |
| 100 | { | |
| 101 | my $msg = shift; | |
| 102 | print STDERR "*** ERROR: strelnokoff: $msg\n"; | |
| 103 | } | |
| 104 | ||
| 105 | ### SYMBOL TABLE ### | |
| 106 | ||
| 107 | %sym = (); | |
| 108 | ||
| 109 | ### PARSER ### | |
| 110 | ||
| 111 | # Strelnokoff = {Assignment}. | |
| 112 | # Assignment = Variable [Index] "=" Expression0. | |
| 113 | # Expression0 = Expression1 {"=" Expression1 | ">" Expression1}. | |
| 114 | # Expression1 = Expression2 {"+" Expression2 | "-" Expression2}. | |
| 115 | # Expression2 = Primitive {"*" Primitive | "/" Primitive}. | |
| 116 | # Primitive = ["PRINT" | "INPUT"] ["CHAR"] Variable [Index] | |
| 117 | # | IntegerLiteral | CharLiteral | |
| 118 | # | "(" Expression0 ")". | |
| 119 | # Index = "[" Expression0 {"," Expression0} "]". | |
| 120 | ||
| 121 | # Program ::= {Assignment}. | |
| 122 | sub program | |
| 123 | { | |
| 124 | my @p = (); | |
| 125 | while($token ne '') | |
| 126 | { | |
| 127 | my $x = assignment(); | |
| 128 | push @p, $x; | |
| 129 | # print join(', ', @$x); | |
| 130 | } | |
| 131 | # print "end program on $token\n"; | |
| 132 | return \@p; | |
| 133 | } | |
| 134 | ||
| 135 | # Assignment ::= Variable [Index] "=" Expression0. | |
| 136 | ||
| 137 | sub assignment | |
| 138 | { | |
| 139 | my $varname = $token; | |
| 140 | scan(); | |
| 141 | if ($token eq '[') | |
| 142 | { | |
| 143 | varindex(); | |
| 144 | } | |
| 145 | expect('='); | |
| 146 | return [':=', $varname, expression0()]; | |
| 147 | # print "$varname = $sym{$varname}\n"; | |
| 148 | } | |
| 149 | ||
| 150 | # Expression0 = Expression1 {"=" Expression1 | ">" Expression1}. | |
| 151 | ||
| 152 | sub expression0 | |
| 153 | { | |
| 154 | my $q = expression1(); | |
| 155 | while($token eq "=" or $token eq ">") | |
| 156 | { | |
| 157 | my $t = $token; | |
| 158 | scan(); | |
| 159 | my $r = expression1(); | |
| 160 | my $b = $q; | |
| 161 | if ($t eq '=') { $q = ['=', $q, $r]; } | |
| 162 | if ($t eq '>') { $q = ['>', $q, $r]; } | |
| 163 | # print "compare: $b $t $r -> $q\n"; | |
| 164 | } | |
| 165 | return $q; | |
| 166 | } | |
| 167 | ||
| 168 | # Expression1 = Expression2 {"+" Expression2 | "-" Expression2}. | |
| 169 | ||
| 170 | sub expression1 | |
| 171 | { | |
| 172 | my $q = expression2(); | |
| 173 | while($token eq "+" or $token eq "-") | |
| 174 | { | |
| 175 | my $t = $token; | |
| 176 | scan(); | |
| 177 | my $r = expression2(); | |
| 178 | if ($t eq '+') { $q = ['+', $q, $r]; } | |
| 179 | if ($t eq '-') { $q = ['-', $q, $r]; } | |
| 180 | } | |
| 181 | return $q; | |
| 182 | } | |
| 183 | ||
| 184 | # Expression2 = Primitive {"*" Primitive | "/" Primitive}. | |
| 185 | ||
| 186 | sub expression2 | |
| 187 | { | |
| 188 | my $q = primitive(); | |
| 189 | while($token eq "*" or $token eq "/") | |
| 190 | { | |
| 191 | my $t = $token; | |
| 192 | scan(); | |
| 193 | my $r = primitive(); | |
| 194 | if ($t eq '*') { $q = ['*', $q, $r]; } | |
| 195 | if ($t eq '/') { $q = ['/', $q, $r]; } | |
| 196 | } | |
| 197 | return $q; | |
| 198 | } | |
| 199 | ||
| 200 | # Primitive = ["PRINT" | "INPUT"] ["CHAR"] Variable [Index] | |
| 201 | # | IntegerLiteral | CharLiteral | |
| 202 | # | "(" Expression0 ")". | |
| 203 | ||
| 204 | sub primitive | |
| 205 | { | |
| 206 | my $mode = 0; # listen up, kids: this is called *context* :-) | |
| 207 | if ($token eq 'PRINT') | |
| 208 | { | |
| 209 | $mode = 1; | |
| 210 | scan(); | |
| 211 | } | |
| 212 | elsif ($token eq 'INPUT') | |
| 213 | { | |
| 214 | $mode = 2; | |
| 215 | scan(); | |
| 216 | } | |
| 217 | if ($token eq 'CHAR') | |
| 218 | { | |
| 219 | $mode = 3 if $mode == 1; | |
| 220 | $mode = 4 if $mode == 2; | |
| 221 | scan(); | |
| 222 | } | |
| 223 | if ($token =~ /^(\d+)$/) | |
| 224 | { | |
| 225 | my $q = 0+$1; | |
| 226 | scan(); | |
| 227 | return ['print', 'int', $q] if $mode == 1; | |
| 228 | return ['print', 'char', $q] if $mode == 3; | |
| 229 | return $q; | |
| 230 | } | |
| 231 | elsif ($token =~ /^\'(.)\'$/) | |
| 232 | { | |
| 233 | my $q = ord($1); | |
| 234 | scan(); | |
| 235 | return ['print', 'int', $q] if $mode == 1; | |
| 236 | return ['print', 'char', $q] if $mode == 3; | |
| 237 | return $q; | |
| 238 | } | |
| 239 | elsif ($token eq '(') | |
| 240 | { | |
| 241 | scan(); | |
| 242 | my $q = expression0(); | |
| 243 | expect(')'); | |
| 244 | return ['print', 'int', $q] if $mode == 1; | |
| 245 | return ['print', 'char', $q] if $mode == 3; | |
| 246 | return $q; | |
| 247 | } | |
| 248 | else | |
| 249 | { | |
| 250 | $sym{$token} = 0 if not exists $sym{$token}; | |
| 251 | $q = [':', $token, 0]; | |
| 252 | scan(); | |
| 253 | if($token eq '[') | |
| 254 | { | |
| 255 | varindex(); | |
| 256 | } | |
| 257 | return ['print', 'int', $q] if $mode == 1; | |
| 258 | return ['print', 'char', $q] if $mode == 3; | |
| 259 | return $q; | |
| 260 | } | |
| 261 | } | |
| 262 | ||
| 263 | # Index = "[" Expression0 {"," Expression0} "]". | |
| 264 | sub varindex | |
| 265 | { | |
| 266 | error("arrays not implemented"); | |
| 267 | expect('['); | |
| 268 | my $q = expression0(); | |
| 269 | while($token eq ',') | |
| 270 | { | |
| 271 | scan(); | |
| 272 | $q .= expression0(); | |
| 273 | } | |
| 274 | expect(']'); | |
| 275 | return $q; | |
| 276 | } | |
| 277 | ||
| 278 | ### EVALUATOR ### | |
| 279 | ||
| 280 | sub dumpic | |
| 281 | { | |
| 282 | my $x = shift; | |
| 283 | if(ref($x) eq 'ARRAY') | |
| 284 | { | |
| 285 | my $c = $x->[0]; | |
| 286 | my $q = $x->[1] || 0; | |
| 287 | my $r = $x->[2] || 0; | |
| 288 | print "[$c "; | |
| 289 | dumpic($q); | |
| 290 | print " "; | |
| 291 | dumpic($r); | |
| 292 | print "] "; | |
| 293 | } else | |
| 294 | { | |
| 295 | print $x; | |
| 296 | } | |
| 297 | } | |
| 298 | ||
| 299 | sub evaluate | |
| 300 | { | |
| 301 | my $x = shift; | |
| 302 | if(ref($x) eq 'ARRAY') | |
| 303 | { | |
| 304 | my $c = $x->[0]; | |
| 305 | # print "--> command: $c\n"; # <STDIN>; | |
| 306 | my $q = $x->[1] || 0; | |
| 307 | my $r = $x->[2] || 0; | |
| 308 | if ($c eq '+') { $q = evaluate($q) + evaluate($r) } | |
| 309 | elsif ($c eq '-') { $q = evaluate($q) - evaluate($r) } | |
| 310 | elsif ($c eq '*') | |
| 311 | { | |
| 312 | # multiplication is interesting in strelnokoff | |
| 313 | # because it is short circuiting :-) | |
| 314 | $q = evaluate($q); | |
| 315 | if ($q != 0) | |
| 316 | { | |
| 317 | $q *= evaluate($r); | |
| 318 | } | |
| 319 | } | |
| 320 | elsif ($c eq '/') | |
| 321 | { | |
| 322 | # division is also interesting | |
| 323 | # because division by 0 yields 0 | |
| 324 | $q = evaluate($q); | |
| 325 | $r = evaluate($r); | |
| 326 | if ($r != 0) | |
| 327 | { | |
| 328 | $q = int($q / $r); | |
| 329 | } else | |
| 330 | { | |
| 331 | $q = 0; | |
| 332 | } | |
| 333 | } | |
| 334 | elsif ($c eq '=') | |
| 335 | { | |
| 336 | if(evaluate($q) == evaluate($r)) | |
| 337 | { | |
| 338 | $q = 1; | |
| 339 | } else | |
| 340 | { | |
| 341 | $q = 0; | |
| 342 | } | |
| 343 | } | |
| 344 | elsif ($c eq '>') | |
| 345 | { | |
| 346 | if(evaluate($q) > evaluate($r)) | |
| 347 | { | |
| 348 | $q = 1; | |
| 349 | } else | |
| 350 | { | |
| 351 | $q = 0; | |
| 352 | } | |
| 353 | } | |
| 354 | elsif ($c eq 'print') | |
| 355 | { | |
| 356 | $r = evaluate($r); | |
| 357 | if ($q eq 'char') { print chr($r); } else { print $r; } | |
| 358 | $q = $r; | |
| 359 | } | |
| 360 | elsif ($c eq ':=') | |
| 361 | { | |
| 362 | $sym{$q} = evaluate($r); | |
| 363 | $q = $sym{$q}; | |
| 364 | } | |
| 365 | elsif ($c eq ':') | |
| 366 | { | |
| 367 | $q = $sym{$q}; | |
| 368 | } | |
| 369 | else | |
| 370 | { | |
| 371 | error("unknown runtime command $c"); | |
| 372 | } | |
| 373 | return $q; | |
| 374 | } else | |
| 375 | { | |
| 376 | return $x; | |
| 377 | } | |
| 378 | } | |
| 379 | ||
| 380 | ### MAIN ### | |
| 381 | ||
| 382 | $| = 1; | |
| 383 | open FILE, "<$ARGV[0]"; | |
| 384 | $program = join('', <FILE>); | |
| 385 | close FILE; | |
| 386 | scan(); | |
| 387 | $assignments = program(); | |
| 388 | $done = 0; | |
| 389 | while (not $done) | |
| 390 | { | |
| 391 | my $no = int(rand(1) * ($#{$assignments}+1)); | |
| 392 | my $assignment = $assignments->[$no]; | |
| 393 | # print "Assignment # $no\n"; | |
| 394 | # dumpic($assignment); <STDIN>; | |
| 395 | evaluate($assignment); | |
| 396 | } | |
| 397 | ||
| 398 | ### END of strelnokoff.pl ### |
| 0 | #!/usr/local/bin/perl -w | |
| 1 | ||
| 2 | # strelnokoff.pl - Cat's Eye Technologies' Strelnokoff Interpreter | |
| 3 | # v2001.03.24 Chris Pressey, Cat's Eye Technologies | |
| 4 | ||
| 5 | # Copyright (c)2001, Cat's Eye Technologies. | |
| 6 | # All rights reserved. | |
| 7 | # | |
| 8 | # Redistribution and use in source and binary forms, with or without | |
| 9 | # modification, are permitted provided that the following conditions | |
| 10 | # are met: | |
| 11 | # | |
| 12 | # Redistributions of source code must retain the above copyright | |
| 13 | # notice, this list of conditions and the following disclaimer. | |
| 14 | # | |
| 15 | # Redistributions in binary form must reproduce the above copyright | |
| 16 | # notice, this list of conditions and the following disclaimer in | |
| 17 | # the documentation and/or other materials provided with the | |
| 18 | # distribution. | |
| 19 | # | |
| 20 | # Neither the name of Cat's Eye Technologies nor the names of its | |
| 21 | # contributors may be used to endorse or promote products derived | |
| 22 | # from this software without specific prior written permission. | |
| 23 | # | |
| 24 | # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND | |
| 25 | # CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
| 26 | # INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
| 27 | # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 28 | # DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE | |
| 29 | # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, | |
| 30 | # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
| 31 | # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, | |
| 32 | # OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | |
| 33 | # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
| 34 | # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 35 | # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 36 | # POSSIBILITY OF SUCH DAMAGE. | |
| 37 | ||
| 38 | # USAGE: [perl] strelnokoff[.pl] program.skf | |
| 39 | ||
| 40 | ### BEGIN strelnokoff.pl ### | |
| 41 | ||
| 42 | ### SCANNER ### | |
| 43 | ||
| 44 | $program = ''; | |
| 45 | $token = ''; | |
| 46 | sub scan | |
| 47 | { | |
| 48 | if ($program =~ /^\s+/) | |
| 49 | { | |
| 50 | $program = $'; | |
| 51 | goto &scan; | |
| 52 | } | |
| 53 | if ($program =~ /^REM.*?\n/) | |
| 54 | { | |
| 55 | $program = $'; | |
| 56 | goto &scan; | |
| 57 | } | |
| 58 | if ($program =~ /^(\d+)/) | |
| 59 | { | |
| 60 | $token = $1; | |
| 61 | $program = $'; | |
| 62 | } | |
| 63 | elsif ($program =~ /^([A-Za-z_][A-Za-z0-9_]*)/) | |
| 64 | { | |
| 65 | $token = $1; | |
| 66 | $program = $'; | |
| 67 | } | |
| 68 | elsif ($program =~ /^(\'.\')/) | |
| 69 | { | |
| 70 | $token = $1; | |
| 71 | $program = $'; | |
| 72 | } | |
| 73 | elsif ($program =~ /^(.)/) | |
| 74 | { | |
| 75 | $token = $1; | |
| 76 | $program = $'; | |
| 77 | } | |
| 78 | else | |
| 79 | { | |
| 80 | # end of program | |
| 81 | $token = ''; | |
| 82 | $program = ''; | |
| 83 | } | |
| 84 | # print "Scanned: $token\n"; | |
| 85 | } | |
| 86 | ||
| 87 | sub expect | |
| 88 | { | |
| 89 | my $expected = shift; | |
| 90 | if ($token eq $expected) | |
| 91 | { | |
| 92 | scan(); | |
| 93 | } else | |
| 94 | { | |
| 95 | error("Expected '$expected' not '$token'"); | |
| 96 | } | |
| 97 | } | |
| 98 | ||
| 99 | sub error | |
| 100 | { | |
| 101 | my $msg = shift; | |
| 102 | print STDERR "*** ERROR: strelnokoff: $msg\n"; | |
| 103 | } | |
| 104 | ||
| 105 | ### SYMBOL TABLE ### | |
| 106 | ||
| 107 | %sym = (); | |
| 108 | ||
| 109 | ### PARSER ### | |
| 110 | ||
| 111 | # Strelnokoff = {Assignment}. | |
| 112 | # Assignment = Variable [Index] "=" Expression0. | |
| 113 | # Expression0 = Expression1 {"=" Expression1 | ">" Expression1}. | |
| 114 | # Expression1 = Expression2 {"+" Expression2 | "-" Expression2}. | |
| 115 | # Expression2 = Primitive {"*" Primitive | "/" Primitive}. | |
| 116 | # Primitive = ["PRINT" | "INPUT"] ["CHAR"] Variable [Index] | |
| 117 | # | IntegerLiteral | CharLiteral | |
| 118 | # | "(" Expression0 ")". | |
| 119 | # Index = "[" Expression0 {"," Expression0} "]". | |
| 120 | ||
| 121 | # Program ::= {Assignment}. | |
| 122 | sub program | |
| 123 | { | |
| 124 | my @p = (); | |
| 125 | while($token ne '') | |
| 126 | { | |
| 127 | my $x = assignment(); | |
| 128 | push @p, $x; | |
| 129 | # print join(', ', @$x); | |
| 130 | } | |
| 131 | # print "end program on $token\n"; | |
| 132 | return \@p; | |
| 133 | } | |
| 134 | ||
| 135 | # Assignment ::= Variable [Index] "=" Expression0. | |
| 136 | ||
| 137 | sub assignment | |
| 138 | { | |
| 139 | my $varname = $token; | |
| 140 | scan(); | |
| 141 | if ($token eq '[') | |
| 142 | { | |
| 143 | varindex(); | |
| 144 | } | |
| 145 | expect('='); | |
| 146 | return [':=', $varname, expression0()]; | |
| 147 | # print "$varname = $sym{$varname}\n"; | |
| 148 | } | |
| 149 | ||
| 150 | # Expression0 = Expression1 {"=" Expression1 | ">" Expression1}. | |
| 151 | ||
| 152 | sub expression0 | |
| 153 | { | |
| 154 | my $q = expression1(); | |
| 155 | while($token eq "=" or $token eq ">") | |
| 156 | { | |
| 157 | my $t = $token; | |
| 158 | scan(); | |
| 159 | my $r = expression1(); | |
| 160 | my $b = $q; | |
| 161 | if ($t eq '=') { $q = ['=', $q, $r]; } | |
| 162 | if ($t eq '>') { $q = ['>', $q, $r]; } | |
| 163 | # print "compare: $b $t $r -> $q\n"; | |
| 164 | } | |
| 165 | return $q; | |
| 166 | } | |
| 167 | ||
| 168 | # Expression1 = Expression2 {"+" Expression2 | "-" Expression2}. | |
| 169 | ||
| 170 | sub expression1 | |
| 171 | { | |
| 172 | my $q = expression2(); | |
| 173 | while($token eq "+" or $token eq "-") | |
| 174 | { | |
| 175 | my $t = $token; | |
| 176 | scan(); | |
| 177 | my $r = expression2(); | |
| 178 | if ($t eq '+') { $q = ['+', $q, $r]; } | |
| 179 | if ($t eq '-') { $q = ['-', $q, $r]; } | |
| 180 | } | |
| 181 | return $q; | |
| 182 | } | |
| 183 | ||
| 184 | # Expression2 = Primitive {"*" Primitive | "/" Primitive}. | |
| 185 | ||
| 186 | sub expression2 | |
| 187 | { | |
| 188 | my $q = primitive(); | |
| 189 | while($token eq "*" or $token eq "/") | |
| 190 | { | |
| 191 | my $t = $token; | |
| 192 | scan(); | |
| 193 | my $r = primitive(); | |
| 194 | if ($t eq '*') { $q = ['*', $q, $r]; } | |
| 195 | if ($t eq '/') { $q = ['/', $q, $r]; } | |
| 196 | } | |
| 197 | return $q; | |
| 198 | } | |
| 199 | ||
| 200 | # Primitive = ["PRINT" | "INPUT"] ["CHAR"] Variable [Index] | |
| 201 | # | IntegerLiteral | CharLiteral | |
| 202 | # | "(" Expression0 ")". | |
| 203 | ||
| 204 | sub primitive | |
| 205 | { | |
| 206 | my $mode = 0; # listen up, kids: this is called *context* :-) | |
| 207 | if ($token eq 'PRINT') | |
| 208 | { | |
| 209 | $mode = 1; | |
| 210 | scan(); | |
| 211 | } | |
| 212 | elsif ($token eq 'INPUT') | |
| 213 | { | |
| 214 | $mode = 2; | |
| 215 | scan(); | |
| 216 | } | |
| 217 | if ($token eq 'CHAR') | |
| 218 | { | |
| 219 | $mode = 3 if $mode == 1; | |
| 220 | $mode = 4 if $mode == 2; | |
| 221 | scan(); | |
| 222 | } | |
| 223 | if ($token =~ /^(\d+)$/) | |
| 224 | { | |
| 225 | my $q = 0+$1; | |
| 226 | scan(); | |
| 227 | return ['print', 'int', $q] if $mode == 1; | |
| 228 | return ['print', 'char', $q] if $mode == 3; | |
| 229 | return $q; | |
| 230 | } | |
| 231 | elsif ($token =~ /^\'(.)\'$/) | |
| 232 | { | |
| 233 | my $q = ord($1); | |
| 234 | scan(); | |
| 235 | return ['print', 'int', $q] if $mode == 1; | |
| 236 | return ['print', 'char', $q] if $mode == 3; | |
| 237 | return $q; | |
| 238 | } | |
| 239 | elsif ($token eq '(') | |
| 240 | { | |
| 241 | scan(); | |
| 242 | my $q = expression0(); | |
| 243 | expect(')'); | |
| 244 | return ['print', 'int', $q] if $mode == 1; | |
| 245 | return ['print', 'char', $q] if $mode == 3; | |
| 246 | return $q; | |
| 247 | } | |
| 248 | else | |
| 249 | { | |
| 250 | $sym{$token} = 0 if not exists $sym{$token}; | |
| 251 | $q = [':', $token, 0]; | |
| 252 | scan(); | |
| 253 | if($token eq '[') | |
| 254 | { | |
| 255 | varindex(); | |
| 256 | } | |
| 257 | return ['print', 'int', $q] if $mode == 1; | |
| 258 | return ['print', 'char', $q] if $mode == 3; | |
| 259 | return $q; | |
| 260 | } | |
| 261 | } | |
| 262 | ||
| 263 | # Index = "[" Expression0 {"," Expression0} "]". | |
| 264 | sub varindex | |
| 265 | { | |
| 266 | error("arrays not implemented"); | |
| 267 | expect('['); | |
| 268 | my $q = expression0(); | |
| 269 | while($token eq ',') | |
| 270 | { | |
| 271 | scan(); | |
| 272 | $q .= expression0(); | |
| 273 | } | |
| 274 | expect(']'); | |
| 275 | return $q; | |
| 276 | } | |
| 277 | ||
| 278 | ### EVALUATOR ### | |
| 279 | ||
| 280 | sub dumpic | |
| 281 | { | |
| 282 | my $x = shift; | |
| 283 | if(ref($x) eq 'ARRAY') | |
| 284 | { | |
| 285 | my $c = $x->[0]; | |
| 286 | my $q = $x->[1] || 0; | |
| 287 | my $r = $x->[2] || 0; | |
| 288 | print "[$c "; | |
| 289 | dumpic($q); | |
| 290 | print " "; | |
| 291 | dumpic($r); | |
| 292 | print "] "; | |
| 293 | } else | |
| 294 | { | |
| 295 | print $x; | |
| 296 | } | |
| 297 | } | |
| 298 | ||
| 299 | sub evaluate | |
| 300 | { | |
| 301 | my $x = shift; | |
| 302 | if(ref($x) eq 'ARRAY') | |
| 303 | { | |
| 304 | my $c = $x->[0]; | |
| 305 | # print "--> command: $c\n"; # <STDIN>; | |
| 306 | my $q = $x->[1] || 0; | |
| 307 | my $r = $x->[2] || 0; | |
| 308 | if ($c eq '+') { $q = evaluate($q) + evaluate($r) } | |
| 309 | elsif ($c eq '-') { $q = evaluate($q) - evaluate($r) } | |
| 310 | elsif ($c eq '*') | |
| 311 | { | |
| 312 | # multiplication is interesting in strelnokoff | |
| 313 | # because it is short circuiting :-) | |
| 314 | $q = evaluate($q); | |
| 315 | if ($q != 0) | |
| 316 | { | |
| 317 | $q *= evaluate($r); | |
| 318 | } | |
| 319 | } | |
| 320 | elsif ($c eq '/') | |
| 321 | { | |
| 322 | # division is also interesting | |
| 323 | # because division by 0 yields 0 | |
| 324 | $q = evaluate($q); | |
| 325 | $r = evaluate($r); | |
| 326 | if ($r != 0) | |
| 327 | { | |
| 328 | $q = int($q / $r); | |
| 329 | } else | |
| 330 | { | |
| 331 | $q = 0; | |
| 332 | } | |
| 333 | } | |
| 334 | elsif ($c eq '=') | |
| 335 | { | |
| 336 | if(evaluate($q) == evaluate($r)) | |
| 337 | { | |
| 338 | $q = 1; | |
| 339 | } else | |
| 340 | { | |
| 341 | $q = 0; | |
| 342 | } | |
| 343 | } | |
| 344 | elsif ($c eq '>') | |
| 345 | { | |
| 346 | if(evaluate($q) > evaluate($r)) | |
| 347 | { | |
| 348 | $q = 1; | |
| 349 | } else | |
| 350 | { | |
| 351 | $q = 0; | |
| 352 | } | |
| 353 | } | |
| 354 | elsif ($c eq 'print') | |
| 355 | { | |
| 356 | $r = evaluate($r); | |
| 357 | if ($q eq 'char') { print chr($r); } else { print $r; } | |
| 358 | $q = $r; | |
| 359 | } | |
| 360 | elsif ($c eq ':=') | |
| 361 | { | |
| 362 | $sym{$q} = evaluate($r); | |
| 363 | $q = $sym{$q}; | |
| 364 | } | |
| 365 | elsif ($c eq ':') | |
| 366 | { | |
| 367 | $q = $sym{$q}; | |
| 368 | } | |
| 369 | else | |
| 370 | { | |
| 371 | error("unknown runtime command $c"); | |
| 372 | } | |
| 373 | return $q; | |
| 374 | } else | |
| 375 | { | |
| 376 | return $x; | |
| 377 | } | |
| 378 | } | |
| 379 | ||
| 380 | ### MAIN ### | |
| 381 | ||
| 382 | $| = 1; | |
| 383 | open FILE, "<$ARGV[0]"; | |
| 384 | $program = join('', <FILE>); | |
| 385 | close FILE; | |
| 386 | scan(); | |
| 387 | $assignments = program(); | |
| 388 | $done = 0; | |
| 389 | while (not $done) | |
| 390 | { | |
| 391 | my $no = int(rand(1) * ($#{$assignments}+1)); | |
| 392 | my $assignment = $assignments->[$no]; | |
| 393 | # print "Assignment # $no\n"; | |
| 394 | # dumpic($assignment); <STDIN>; | |
| 395 | evaluate($assignment); | |
| 396 | } | |
| 397 | ||
| 398 | ### END of strelnokoff.pl ### |