simplify huge c++ template typenames by finding common subexpressions.

symboldecode.pl

# (C) 2003-2007 Willem Jan Hengeveld <itsme@xs4all.nl>
# Web: http://www.xs4all.nl/~itsme/
#      http://wiki.xda-developers.com/
#
#  attempt to make complicated template symbols more readable
#
# $Id: $
#
use strict;
use warnings;

use Getopt::Long;
my $verbose=0;
GetOptions(
    "v" => \$verbose
);

# tool to go from this:
# 
# public: __thiscall boost::spirit::binary<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t>,struct boost::spirit::parser<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > > >::binary<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t>,struct boost::spirit::parser<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > > >(struct boost::spirit::alternative<struct boost::spirit::alternative<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > >,struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> >,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> > > const &,class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t> const &)
# 
# to this:
# 
# A=class boost::spirit::rule<class boost::spirit::scanner<class std::vector<char,class std::allocator<char> >::const_iterator,struct boost::spirit::scanner_policies<struct boost::spirit::iteration_policy,struct boost::spirit::match_policy,struct boost::spirit::action_policy> >,struct boost::spirit::nil_t,struct boost::spirit::nil_t>
# B=struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::sequence<struct boost::spirit::chlit<char>,class boost::spirit::strlit<char const *> >,A >,A >
# C=struct boost::spirit::alternative<struct boost::spirit::alternative<B,B >,B >
# D=struct boost::spirit::parser<struct boost::spirit::alternative<C,A > >
# 
# public: __thiscall boost::spirit::binary<C,A,D >::binary<C,A,D >(C const &,A const &)
# 
# 
# do this by first replacing [a-z:]+<[^>]+>  with  new symbol, until everything is a symbol.
# then expand again symbols which occur only once.
# 
#

while (<>) {
    s/\s+$//;
    process($_);
}
sub process {
    my $symbol= shift;

    # first build symbol table, replacing template<params>  with symbol.
    my %symtab;
    my $n= 0;
    while ($symbol =~ /((?:\w+\s+)*[_a-z0-9:]+<[^<>]+>)/) {
        my $s= $1;
        $symtab{++$n}= $s;

        $s =~ s/[*+?{().^\$\\\[]/\\$&/g;    # escape regexp chars in $s
        $symbol =~ s/$s/ #${n}# /g;
    }


    # now calc the xrefs, how often is each symbol used.
    my %ref;
    for my $n (keys %symtab) {
        my $s= " #${n}# ";
        $ref{$n}= scalar @{[$symbol =~ /($s)/g]};
        $ref{$n}+= scalar @{[$_ =~ /($s)/g]} for values %symtab;
    }

    #printf("#%d# : %d\n", $_, $ref{$_}) for keys %ref;

    # if everything has 1 ref, print the result now.
    if ($verbose ||!grep { $ref{$_}!=1 } keys %ref) {
        printf("#%d#: %s\n", $_, $symtab{$_}) for sort { $a<=>$b } keys %symtab;
        printf("%s\n", $symbol);
    }

    # now reexpand symbols that are only used once.
    for my $n (grep { $ref{$_}==1 }  keys %ref) {
        #printf("%d : %d : %s\n", $n, $count{$n}, $symtab{$n});
        my $s= $symtab{$n};
        $symtab{$_} =~ s/ #${n}# /$s/g for keys %symtab;
        $symbol =~ s/ #${n}# /$s/g;
        delete $symtab{$n};
    }

    # and output the result.
    if (keys %symtab) {
        printf("#%d#: %s\n", $_, $symtab{$_}) for sort { $a<=>$b } keys %symtab;
        printf("%s\n", $symbol);
    }
}