#!/bin/sh
exec perl -e '

# TODO finish it!
# to test, e.g.
#   b2b0 < brace.b | ./e2b | less

# looking for more than one token together without space and with balanced brackets and not already bracketed

use strict; use warnings;

require "brace_parser.pl";

our @lines;

read_lines(\*STDIN);

use Data::Dumper;

for (@lines) {
	chomp;
	my $tokens = tokenize_ng($_);
	$tokens = process_expr($tokens);
	$_ = untokenize_ng_spaces($tokens)."\n";
}

output_lines();


sub process_expr {
	my ($tokens) = @_;
	my $continue;
	for (@$tokens) {
		if (ref $_) {
			$_ = process_expr($_);
		}
	}
	do {
		$continue = 0;
		my $out = [];
		while (@$tokens) {
			my ($expr, $continue1);
			($expr, $tokens, $continue1) = process_expr_1($tokens);
			push @$out, @$expr;
			$continue ||= $continue1;
		}
		$tokens = $out;
	} while $continue;
	return $tokens;
}

sub process_expr_1 {
	my ($tokens) = @_;
	my $continue = 0;
	my $out = [];

	while (@$tokens) {
		my $t = shift @$tokens;
		if (ref $t) {
			push @$out, process_expr($t);
		} elsif ($t =~ /^[]})({[]$/) {
			push @$out, $t;
		} elsif ($t =~ /^\s+$/) {
			if ($t =~ /^ ( *)$/) {
				if (length($1)) {
					push @$out, $1;
					$continue = 1;
				}
			} else {
				push @$out, $t;
			}
		} else {
			# a non-space token
			my @collect;
			my $c = 0;
			while(1) {
				if (!ref $t and $t =~ /^[])}]$/ || $t =~ /^\s+$/) {
					unshift @$tokens, $t;
					last;
				}
				push @collect, $t;
				if (@$tokens == 0) { last }
				$t = shift @$tokens;
			}
			if (@collect > 1) {
				if (@$out && $$out[-1] =~ /^[({[]$/ && @$tokens && $$tokens[0] =~ /^[])}]$/) {
					push @$out, @collect;
				} else {
					unshift @$tokens, ["(", @collect, ")"];
				}
			} else {
				push @$out, @collect;
			}
		}
	}

	return $out, $tokens, $continue;
}

sub untokenize_ng_spaces {
	my ($tokens) = @_;
	my $text = "";
	for (@$tokens) {
		if ($text ne "") {
			$text .= " ";
		}
		if (ref $_) {
			$text .= untokenize_ng_spaces($_);
		} else {
			$text .= $_;
		}
	}
	return $text;
}
' "$@"