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Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
garbage
/

The tokenizer will wipe out "garbage" without a warning. This could hide some bugs. I think it would be better to use a more sophisticated parser that can detect syntax errors.

In other words: the language is underspecified. (Thanks @200_success!)

Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
garbage
/

The tokenizer will wipe out "garbage" without a warning. This could hide some bugs. I think it would be better to use a more sophisticated parser that can detect syntax errors.

In other words: the language is underspecified. (Thanks @200_success!)

Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
garbage
/

The tokenizer will wipe out the garbage I added there without a warning. This could hide some bugs. I think it would be better to use a bit more sophisticated parser that can detect syntax errors.

Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
garbage
/

The tokenizer will wipe out "garbage" without a warning. This could hide some bugs. I think it would be better to use a more sophisticated parser that can detect syntax errors.

In other words: the language is underspecified. (Thanks @200_success!)

Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
%    garbage
/

The tokenizer will wipe out the % garbage I added there without a warning. This could hide some bugs. I think it would be better to use a bit more sophisticated parser that can detect syntax errors.

Just one small point that @200_success probably left out so I can say something too: when matching something against $_, for example in if ($_ =~ /[0-9]+/) { ... }, you can simply omit the $_:

if (/[0-9]+/) {
    # ...
}

It's "the default input and pattern-searching space". Read more about the $_ variable in man perlvar or on perldoc.perl.org.

The main loop in generate_assembly rewritten to use this (+ a hashmap for the operators):

my %ops = (
    '+' => "pop ebx\npop eax\nadd eax,ebx\npush eax\n",
    '-' => "pop ebx\npop eax\nsub eax,ebx\npush eax\n",
    '/' => "mov edx,0\npop ecx\npop eax\ndiv ecx\npush eax\n",
    '*' => "mov edx,0\npop ecx\npop eax\nmul ecx\npush eax\n",
    '.' => "push message\ncall printf\nadd esp, 8\n",
);
foreach (@tokens) {
    say "<$_>";
    if (/[0-9]+/) {
        $assembly .= "push $_\n";
    } else {
        $assembly .= $ops{$_};
    }
}

This made me notice one more point: if I add garbage in the input file like this:

256
2
garbage
/

The tokenizer will wipe out the garbage I added there without a warning. This could hide some bugs. I think it would be better to use a bit more sophisticated parser that can detect syntax errors.