libtext-reflow-perl 1.11-1build1 / usr / share / doc / libtext-reflow-perl / examples / reflow

#!/usr/bin/perl -w
# Version 7.0
# Original script written by Michael Larsen, larsen@edu.upenn.math 
# Modified by Martin Ward, martin@gkc.org.uk
# Copyright 1994 Michael Larsen and Martin Ward
# Email: martin@gkc.org.uk
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# Usage: reflow [-skipto stuff] [-fast|-slow|-veryslow] [-skipindented] src>out
#
# Uses Knuth's paragraphing algorithm (as used in TeX) to "reflow"
# text files by picking "good" places to break the line. 
#
# It takes an ascii text file (with paragraphs separated by blank lines)
# and reflows the paragraphs. If two or more lines in a row are "indented"
# then they are assumed to be a quoted poem and are passed through unchanged.
# (The -skipindented causes ALL indented lines to be passed unchanged)
#
# The "reflow" operation tries to keep the lines the same length but also
# tries to break at punctuation, and avoid breaking within a proper name
# or after certain "connectives" ("a", "the", etc.).
#
# The "-veryslow" option reflows each paragraph 16 times with different
# optimal line widths and picks the "best" result -- with this option
# the paragraphs are easier to read, but the line width may vary from
# one paragraph to the next.
#
#
# Recent version history:
# 5.1: Fixed a bug with hyphens at end of lines
#      (caught by check-punct!)
# 5.2: Avoid turning ". . ." into ".  .  ."
# 5.3: Added an option "-skipto stuff"
#      which skips lines up to and including a line starting with "stuff"
# 5.4: Added an option "-skipindented" which treats ALL indented lines
#      as "poetry" (i.e. not reflow-ed), rather than requiring two
#      indented lines.
# 5.5: Fixed a bug when a paragraph starts with "--"
# 5.6: Tweaked some parameters, and modified to break before rather
#      than after a word which starts with an opening parenthesis
# 5.7: Delete spaces at the end of lines in output.
# 5.8: Added an option "-slow" which tries a list of "optimum" line lengths,
#      picking the one which gives the least total penalties.
# 5.9: Tweaked the parameters a bit more!
# 6.0: Added a "-veryslow" option which uses a LONG list of "optimum" lengths,
#      -veryslow is about 7 times slower than with no options (or -fast)
# 6.1: Added a penalty for paragraphs with 1 or 2 words on the last line.
# 6.2: Fixed a bug in calculating $bestsofar.
# 6.3: Modified to work with perl5beta1 (gaining a 20% speed improvement).
# 6.4: Added "-w" and fixed warnings and a bug with v long first word in para.
# 6.5: Fix 5.1 could leave @linewords empty
#      -- check for hyphen at end of line before checking @linewords
# 6.6: Trim spaces from the ends of lines before printing.
# 6.7: Tweaked "optimum" parameters and reduced maximum to 75
# 6.8: Speed optimisations, including converting all penalties to integers
#      -- now 37% faster on -veryslow
# 7.0: Converted to a module with an XSUB for reflow_trial
#      -- Vast speed improvement!

use Text::Reflow (reflow_file);
use strict;

my @slow_optimum = (65, 70, 60);  # List of best line lengths for -slow option
my @veryslow_optimum = (60..70);  # ditto for -veryslow option
my @fast_optimum = (65);	  # The default

my $Usage = "reflow [-fast|-slow|-veryslow] [-skipto patt] [-skipindented] ...\n";

$| = 1; # unbuffer output
my @opts = ();

# Check for options -skipindented, -fast, -slow, -veryslow for backwards compatibility:
while (($#ARGV >= 0) && ($ARGV[0] =~ /^-/)) {
  if ($ARGV[0] eq "-skipindented") {
    shift;
    if (@ARGV && ($ARGV[0] =~ /^[012]$/)) {
      push(@opts, "skipindented", shift);
    } else {
      push(@opts, "skipindented", 1);
    }
  } elsif ($ARGV[0] eq "-fast") {
    shift;
    push(@opts, "optimum", \@fast_optimum);
  } elsif ($ARGV[0] eq "-slow") {
    shift;
    push(@opts, "optimum", \@slow_optimum);
  } elsif ($ARGV[0] eq "-veryslow") {
    shift;
    push(@opts, "optimum", \@veryslow_optimum);
  } else {
    my $key = shift;
    $key =~ s/^-//;
    my $value = shift;
    push(@opts, $key, $value);
  }
}

push(@ARGV, "") unless (@ARGV); # Read STDIN if no file given

foreach my $file (@ARGV) {
  reflow_file($file, "", @opts);
}