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|
use 5.010;
use warnings;
use Test::More 'no_plan';
use List::Util qw< reduce >;
sub translator {
my ($errormsg, $rulename, $context) = @_;
if (substr($rulename,0,1) eq '-') {
$rulename = substr($rulename,1);
return "You forgot to define $rulename. :-(";
}
if ($errormsg eq q{}) {
if ($rulename) {
return "<$rulename> failed to match '$context'";
}
else {
return "Main pattern failed to match '$context'";
}
}
if (lc(substr($errormsg,0,6)) eq 'wanted') {
return "$errormsg, but was given '$context'. What's up with that?";
}
return $errormsg;
}
my $calculator = do{
use Regexp::Grammars;
qr{
\A
<Answer>
(?:
\Z
|
<warning: (?{ "Extra junk after expression at index $INDEX: '$CONTEXT'" })>
<warning: Wanted end of input>
<error:>
)
<rule: Answer>
<[_Operand=Mult]> ** <[_Op=(\+|\-)]>
(?{ $MATCH = shift @{$MATCH{_Operand}};
for my $term (@{$MATCH{_Operand}}) {
my $op = shift @{$MATCH{_Op}};
if ($op eq '+') { $MATCH += $term; }
else { $MATCH -= $term; }
}
})
|
<Trailing_stuff>
<rule: Mult>
(?:
<[_Operand=Pow]> ** <[_Op=(\*|/|%)]>
(?{ $MATCH = reduce { eval($a . shift(@{$MATCH{_Op}}) . $b) }
@{$MATCH{_Operand}};
})
)
<rule: Pow>
(?:
<[_Operand=Term]> ** <_Op=(\^)>
(?{ $MATCH = reduce { $b ** $a } reverse @{$MATCH{_Operand}}; })
)
<rule: Term>
(?:
<MATCH=Literal>
| \( <MATCH=Answer> \)
)
<rule: Trailing_stuff>
<...>
<token: Literal>
<error:>
|
<MATCH=( [+-]? \d++ (?: \. \d++ )?+ )>
}xms
};
local $/ = "";
{
my $temp = Regexp::Grammars::set_error_translator(\&translator);
while (my $input = <DATA>) {
chomp $input;
my ($text, $expected) = split /\s+/, $input, 2;
if ($text =~ $calculator) {
is $/{Answer}, $expected => "Input $.: $text";
}
else {
is_deeply \@!, eval($expected), => "Input $.: $text";
}
}
}
{
use Regexp::Grammars;
if ('foo' =~ m{ <Answer> <rule: Answer> <...> }xms) {
fail 'Restore default translator';
}
else {
is_deeply \@!, ["Can't match subrule <Answer> (not implemented)"]
=> 'Restore default translator';
}
}
__DATA__
2 2
2*3+4 10
2zoo [
"Extra junk after expression at index 1: 'zoo'",
"Wanted end of input, but was given 'zoo'. What's up with that?",
"Main pattern failed to match 'zoo'",
"You forgot to define Trailing_stuff. :-(",
]
zoo [
"<Literal> failed to match 'zoo'",
"You forgot to define Trailing_stuff. :-(",
]
|
