codegen.pl

#!/usr/bin/perl

use POSIX;
use strict;
use Data::Dumper;

sub gen_combination {
    my ($m,$n,$i) = @_;
    my $q = $i;
    my @res = ();
    for (my $j=0;$j<$n;$j++) {
        my $r = $q % $m;
        $q = int($q / $m);
        push(@res,$r);
    }
    return @res;
}

sub codegen {
    my ($m,$n,$comb_gen,$statements_ref) = @_;
    my @comb = @$comb_gen;
    my @res = ();
    for (@$statements_ref) {
        my %statement = %$_;

        if (!defined $statement{'t'}) {
            print "'t' not defined at statement\n" . Dumper(%statement) . "\n";
            return;
        }
        if (!defined $statement{'s'}) {
            print "'s' not defined at statement\n" . Dumper(%statement) . "\n";
            return;
        }

        my $t = $statement{'t'};
        my @s = @{$statement{'s'}};

        if ($t eq 'p') {
            push(@res,$s[0]);
        } elsif ($t eq 'a') {
            for (my $i=0;$i<$n;$i++) {
                my $p = $s[0];
                if (scalar(@s)>$comb[$i]) {
                    $p = $s[$comb[$i]];
                }
                $p =~ s/%/$i/g;
                push(@res,$p);
            }
        } elsif ($t eq 'j') {
            if (!defined $statement{'j'}) {
                print "'j' is not defined at statement\n" . Dumper(%statement) . "\n";
                return;
            }
            my $j = $statement{'j'};
            my @ps = ();
            for (my $i=0;$i<$n;$i++) {
                my $p = $s[0];
                if (scalar(@s)>$comb[$i]) {
                    $p = $s[$comb[$i]];
                }
                $p =~ s/%/$i/g;
                push(@ps,$p);
            }
            push(@res,join($j,@ps));
        } else {
            print "'t' is not one of 'p','a','j' at statement\n" . Dumper(%statement) . "\n";
            return;
        }

    }
    return join('',@res);
}

sub codegen_ {
    my ($m,$n,$comb_gen,$statements_ref) = @_;
    my @comb = @$comb_gen;
    my @res = ();
    for (@$statements_ref) {
        my @statement = @$_;

        my $t = $statement[0];
        my @s = @{$statement[1]} if scalar(@statement)>1;
        my $j = $statement[2] if scalar(@statement)>2;

        if ($t eq 'p') {
            push(@res,$s[0]);
        } elsif ($t eq 'j') {
            #if (!defined $j) {
            #   print "'j' not defined at statement\n" . Dumper(@statement) . "\n";
            #   return;
            #}
            $j = '' unless defined $j;

            my @ps = ();
            for (my $i=0;$i<$n;$i++) {
                my $p = $s[0];
                if (scalar(@s)>$comb[$i]) {
                    $p = $s[$comb[$i]];
                }
                $p =~ s/%/$i/g;
                push(@ps,$p);
            }
            push(@res,join($j,@ps));
        } else {
            if (scalar(@statement)==1) {
                push(@res,$t);
            } else {
                print "'t' is not one of 'p','j' at statement\n" . Dumper(@statement) . "\n";
                return;
            }
        }
    }
    return join('',@res);
}

my $m = 2;
my $n = 3;
my $o = pow($m,$n);
my @statement = ({'t'=>'a','s'=>['int a%; ','double a%; ']});
for (my $i=0;$i<pow($m,$n);$i++) {
    my @comb = gen_combination($m,$n,$i);
    my @res = codegen($m,$n,\@comb,\@statement);
    print join('',@res) . "\n";
}

my @comb = gen_combination($m,$n,4);
@statement = ({'t'=>'j','s'=>['int a%','double a%'],'j'=>', '});
print "\n" . join('',codegen($m,$n,\@comb,\@statement)) . "\n";

@statement = (
{'t'=>'p','s'=>['QVariant mul(']},
{'t'=>'j','s'=>['int r%, int c%','const QVariant& v%'],'j'=>', '},
{'t'=>'p','s'=>["){\n"]},
{'t'=>'a','s'=>["\tQVariant v%=data(index(r%,c%));\n",'']},
{'t'=>'p','s'=>["\tif ("]},
{'t'=>'j','s'=>["v%.isNull()"],'j'=>' || '},
{'t'=>'p','s'=>[")\n\t\treturn QVariant();\n\treturn "]},
{'t'=>'j','s'=>["v%.toDouble()"],'j'=>'*'},
{'t'=>'p','s'=>[";\n}\n"]},
);
print "\n" . codegen($m,$n,\@comb,\@statement) . "\n";

@statement = (
['p',['QVariant mul(']],
['j',['int r%, int c%','const QVariant& v%'],', '],
['p',["){\n"]],
['j',["\tQVariant v%=data(index(r%,c%));\n",''],''],
['p',["\tif ("]],
['j',["v%.isNull()"],' || '],
['p',[")\n\t\treturn QVariant();\n\treturn "]],
['j',["v%.toDouble()"],'*'],
['p',[";\n}\n"]]
);
print "\n" . codegen_($m,$n,\@comb,\@statement) . "\n";

@statement = (
['QVariant mul('],
['j',['int r%, int c%','const QVariant& v%'],', '],
["){\n"],
['j',["\tQVariant v%=data(index(r%,c%));\n",'']],
["\tif ("],
['j',["v%.isNull()"],' || '],
[")\n\t\treturn QVariant();\n\treturn "],
['j',["v%.toDouble()"],'*'],
[";\n}\n"]
);
print "\n" . codegen_($m,$n,\@comb,\@statement) . "\n";