NAME

Text::Utils - Miscellaneous text utilities

SYNOPSIS

# Export individual routines or :ALL
use Text::Utils :strip-comment;
my $text = q:to/HERE/;
    any kind of text, including code"; # some comment
    my $s = 'foo'; # another comment
    HERE

for $text.lines -> $line is copy {
    $line = strip-comment $line;
    say $line;
}
# OUTPUT with comments removed:
any kind of text, including code;
my $s = 'foo';

DESCRIPTION

The module contains several routines to make text handling easier for module and program authors. Following is a short synopsis and signature for each of the routines.

sub sort-list

#  StrLength, LengthStr, Str, Length, Number
enum Sort-type is export(:sort-list) < SL LS SS LL N >;
sub sort-list(@list, :$type = SL, :$reverse --> List) is export(:sort-list)
{...}

By default, this routine sorts all lists by word length, then by Str order. The order by length is by the shortest abbreviation first unless the :$reverse option is used.

The routine's output can be modified for other uses by entering the :$type parameter to choose another of the enum Sort-types.

sub strip-comment

Strip the comment from an input text line, save comment if requested, normalize returned text if requested.

The routine returns a string of text with any comment stripped off. Note the designated character will trigger the strip even though it is escaped or included in quotes. Also returns the comment, including the comment character, if requested. All returned text is normalized if requested. Any returned comment will also be normalized if the normalize-all option is used in place of normalize.

The signature:

sub strip-comment(
    $line is copy,                # string of text with possible comment
    :mark(:$comment-char) = '#',  # desired comment character indicator
                                  #   (with alias :$comment-char)
    :$save-comment,               # if true, return the comment
    :$normalize,                  # if true, normalize returned string
    :$normalize-all,              # if true, normalize returned string
                                  #   and also normalize any saved comment
    :$last,                       # if true, use the last instead of first 
                                  #   comment character
    ) is export(:strip-comment)
{...}

Note the default return is the returned string without any comment. However, if you use the save-comment option, a two-element list is returned: ($string, $comment) (either element may be "" depending upon the input text line).

sub normalize-string (or its alias 'normalize-text')

This routine trims a string and collapses multiple whitespace characters (including tabs and newlines) into one.

The signature:

sub normalize-string(
    Str:D $str is copy
    --> Str) is export(:normalize-string)
{...}

sub wrap-text

This routine is used in creating PostScript PDF or other output formats where blocks (e.g., paragraphs) need to be wrapped to a specific maximum width based on the font face and font size to be used. Note it has all the options of the wrap-paragraph routine except the :width is expressed in PostScript points (72 per inch) as is the :font-size. The default :width is 468 points, the length of a line on a Letter paper, portrait orientation, with one-inch margins on all sides.

The fonts currently handled are the the 14 PostScript and PDF Core Fonts:

multi sub wrap-text(
    @text,
    Real :$width               = 468, #= PS points for 6.5 inches
         :$font-name           = 'Times-Roman',
    Real :$font-size           = 12,
    #------------------------------#
    UInt :$para-indent         = 0,
    UInt :$first-line-indent   = 0,
    UInt :$line-indent         = 0,
    #------------------------------#
    Str  :$para-pre-text       = '',
    Str  :$first-line-pre-text = '',
    Str  :$line-pre-text       = '',
    #------------------------------#
    :$debug,
    --> List) is export(:wrap-text)
{...}
multi sub wrap-text(
    $text,
    # ... other args same as the other multi
    --> List) is export(:wrap-text)
{...}

sub list2text

Turn a list into a text string for use in a document.

For example, this list 1 2 3 becomes either this "1, 2, and 3" (the default result) or this "1, 2 and 3" (if the $optional-comma named variable is set to false). The default result uses the so-called Oxford Comma which is not popular among some writers, but those authors may change the default behavior by permanently by defining the environment variable TEXT_UTILS_NO_OPTIONAL_COMMA.

The signature:

sub list2text(
    @list,
    :$optional-comma is copy = True
    ) is export(:list2text)
{...}

sub count-substrs

Count instances of a substring in a string.

The signature:

sub count-substrs(
    Str:D $string,
    Str:D $substr
    --> UInt
    ) is export(:count-substrs)
{...}

sub commify

This routine was originally ported from the Perl version in the The Perl Cookbook, 2e.

The routine adds commas to a number to separate multiples of a thousand. For example, given an input of 1234.56, the routine returns 1,234.56.

As an improvement, if real numbers are input, the routine returns the number stringified with two decimal places. The user may specify the desired number with the new :$decimals named argument.

The signature:

sub commify($num, :$decimals --> Str) is export(:commify)
{...}

sub split-line

This routine splits a string into two pieces.

Inputs are the string to be split, the split character, maximum length, a starting position for the search, and the search direction.

It returns the two parts of the split string; the second part will be an empty string if the input string is not too long.

The signature:

sub split-line(
    Str:D $line is copy,
    Str:D $brk,
    UInt  :$max-line-length = 0,
    UInt  :$start-pos       = 0,
    Bool  :$rindex          = False
    --> List) is export(:split-line)
{...}

sub split-line-rw

Splits a string into two pieces.

Inputs are the string to be split, the split character, maximum length, a starting position for the search, and search direction.

It returns the part of the input string past the break character, or an empty string (the input string is modified in-place if it is too long).

The signature:

sub split-line-rw(
    Str:D $line is rw,
    Str:D $brk,
    UInt  :$max-line-length = 0,
    UInt  :$start-pos       = 0,
    Bool  :$rindex          = False
    --> Str) is export(:split-line-rw)
{...}

sub wrap-paragraph

This routine wraps a list of words into a paragraph with a maximum line width in characters (default: 78), and returns a list of the new paragraph's lines formatted as desired. An option, :$para-pre-text, used in conjunction with :$para-indent, is very useful for use in auto-generation of code. For example, given this chunk of text describing a following PDF method MoveTo(x, y):

my $str = q:to/HERE/;
Begin a new sub-path by moving the current point to coordinates (x,
y), omitting any connecting line segment. If the previous path
construction operator in the current path was also m, the new m
overrides it.
HERE

Run that string through the sub to see the results:

my @para = wrap-paragraph $str.lines, :para-pre-text('#| '), :para-indent(4);
.say for @para;

yields:

    #| Begin a new sub-path by moving the current point to coordinates (x, y),
    #| omitting any connecting line segment. If the previous path construction
    #| operator in the current path was also m, the new m overrides it.

The signature:

multi sub wrap-paragraph(
    @text,
    UInt :$max-line-length     = 78,
    #------------------------------#
    UInt :$para-indent         = 0,
    UInt :$first-line-indent   = 0,
    UInt :$line-indent         = 0,
    #------------------------------#
    Str  :$para-pre-text       = '',
    Str  :$first-line-pre-text = '',
    Str  :$line-pre-text       = '',
    #------------------------------#
    :$debug,
    --> List) is export(:wrap-paragraph)
{...}
multi sub wrap-paragraph(
    $text,
    # ... other args same as the other multi
    --> List) is export(:wrap-paragraph)
{...}

AUTHOR

Tom Browder tbrowder@cpan.org

COPYRIGHT AND LICENSE

Copyright © 2019-2024 Tom Browder

This library is free software; you may redistribute it or modify it under the Artistic License 2.0.