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Compiler/lexical analyzer: Difference between revisions
→{{header|Perl}}
Line 3,447:
23 1 End_of_input
</pre>
===Alternate Perl Solution===
Tested on perl v5.26.1
<lang Perl>#!/usr/bin/perl
use strict; # lex.pl - source to tokens
use warnings; # http://www.rosettacode.org/wiki/Compiler/lexical_analyzer
no warnings qw(qw);
my %keywords = map { $_, "Keyword_$_" } qw( while print if else putc );
my %tokens = qw[ ; Semicolon ( LeftParen ) RightParen { LeftBrace } RightBrace
+ Op_add - Op_subtract * Op_multiply % Op_mod = Op_assign >= Op_greaterequal
!= Op_notequal == Op_equal ! Op_not < Op_less <= Op_lessequal > Op_greater
, Comma && Op_and || Op_or ];
local $_ = join '', <>;
while( /\G (?|
\s+ (?{ undef })
| \d+[_a-zA-Z]\w* (?{ die "invalid mixed number $&\n" })
| \d+ (?{ "Integer $&" })
| \w+ (?{ $keywords{$&} || "Identifier $&" })
| ( [-;(){}+*%,] | [=!<>]=? | && | \|\| )
(?{ $tokens{$1} })
| \/ (?{ 'Op_divide' }) (?: \* (?: [\s\S]*?\*\/ (?{ undef }) |
(?{ die "End-of-file in comment\n" }) ) )?
| "[^"\n]*" (?{ "String $&" })
| " (?{ die "unterminated string\n" })
| '' (?{ die "empty character constant\n" })
| '([^\n\\])' (?{ 'Integer ' . ord $1 })
| '\\n' (?{ 'Integer 10' })
| '\\\\' (?{ 'Integer 92' })
| ' (?{ die "unterminated or bad character constant\n" }) #'
| . (?{ die "invalid character $&\n" })
) /gcx )
{
defined $^R and printf "%5d %7d %s\n",
1 + $` =~ tr/\n//, 1 + length $` =~ s/.*\n//sr, $^R;
}
printf "%5d %7d %s\n", 1 + tr/\n//, 1, 'End_of_input';</lang>
=={{header|Perl 6}}==
| |||