1Text::Aligner(3) User Contributed Perl Documentation Text::Aligner(3)
2
6 Text::Aligner
7
9 version 0.13
10
12 use Text::Aligner qw( align );
13 # Print the words "just a test!" right-justified each on a line:
15 my @lines = align( 'right', qw( just a test!);
17 print "$_\n" for @lines;
18
20 Text::Aligner exports a single function, align(), which is used to
21 justify strings to various alignment styles. The alignment
22 specification is the first argument, followed by any number of scalars
23 which are subject to alignment.
24 The operation depends on context. In list context, a list of the
26 justified scalars is returned. In scalar context, the justified
27 arguments are joined into a single string with newlines appended. The
28 original arguments remain unchanged. In void context, in-place
29 justification is attempted. In this case, all arguments must be
30 lvalues.
31 Align() also does one level of scalar dereferencing. That is, whenever
33 one of the arguments is a scalar reference, the scalar pointed to is
34 aligned instead. Other references are simply stringified. An
35 undefined argument is interpreted as an empty string without complaint.
36 Alignment respects colorizing escape sequences a la Term::ANSIColor
38 which means it knows that these sequences don't take up space on the
39 screen.
40
42 Text::Aligner - module to align text.
43
45 The first argument of the align() function is an alignment style, a
46 single scalar.
47 It can be one of the strings "left", "right", "center", "num", "point",
49 or "auto", or a regular expression (qr/.../), or a coderef.
50 A default style of "left" is assumed for every other value, including
52 "" and undef.
53 "left", "right" and "center" have the obvious meanings. These can also
55 be given as numbers 0, 1, and 0.5 respectively. (Other numbers are also
56 possible, but probably not very useful).
57 "num", and its synonym "point", specify that the decimal points be
59 aligned (assumed on the right, unless present). Arbitrary (non-
60 numeric) strings are also aligned in this manner, so they end up one
61 column left of the (possibly assumed) decimal point, flush right with
62 any integers. For the occasional string like "inf", or "-" for missing
63 values, this may be the right place. A string-only column ends up
64 right-aligned (unless there are points present).
65 The "auto" style separates numeric strings (that are composed of "-",
67 ".", and digits in the usual manner) and aligns them numerically.
68 Other strings are left aligned with the number that sticks out farthest
69 to the left. This gives left alignment for string-only columns and
70 numeric alignment for columns of numbers. In mixed columns, strings
71 are reasonably placed to serve as column headings or intermediate
72 titles.
73 With "num" (and "point") it is possible to specify another character
75 for the decimal point in the form "num(,)". In fact, you can specify
76 any string after a leading "(", and the closing ")" is optional.
77 "point(=>)" could be used to align certain pieces of Perl code. This
78 option is currently not available with "auto" alignment (because
79 recognition of numbers is Anglo-centric).
80 If a regular expression is specified, the points are aligned where the
82 first match of the regex starts. A match is assumed immediately after
83 the string if it doesn't match.
84 A regular expression is a powerful way of alignment specification. It
86 can replace most others easily, except center alignment and, of course,
87 the double action of "auto".
88
90 For entirely self-defined forms of alignment, a coderef, also known as
91 a positioner, can be given instead of an alignment style. This code
92 will be called once or more times with the string to be aligned as its
93 argument. It must return two numbers, a width and a position, that
94 describe how to align a string with other strings.
95 The width should normally be the length of the string. The position
97 defines a point relative to the beginning of the string, which is
98 aligned with the positions given for other strings.
99 A zero position for all strings results in left alignment, positioning
101 to the end of the string results in right alignment, and returning half
102 the length gives center alignment. "num" alignment is realized by
103 marking the position of the decimal point.
104 Note that the position you return is a relative measure. Adding a
106 constant value to all positions results in no change in alignment. It
107 doesn't have to point inside the string (as in right alignment, where
108 it points one character past the end of the string).
109 The first return value of a positioner should almost always be the
111 length of the given string. However, it may be useful to lie about the
112 string length if the string contains escape sequences that occupy no
113 place on screen.
114
116 align($style, $str)
117 See above.
118 new(...)
120 For internal use.
121
123 use Text::Aligner qw( align );
124 align( $style, $str, ...);
126 $style must be given and must be an alignment specification.
128 Any number of scalars can follow. An argument that contains a
129 scalar reference is dereferenced before it is used. In scalar
130 and list context, the aligned strings are returned. In void
131 context, the values are aligned in place and must be lvalues.
132
134 None known as of release, but...
135
137 Anno Siegel
138 CPAN ID: ANNO
139
141 Copyright (c) 2002 Anno Siegel. All rights reserved. This program is
142 free software; you can redistribute it and/or modify it under the terms
143 of the ISC license.
144 (This program had been licensed under the same terms as Perl itself up
146 to version 1.118 released on 2011, and was relicensed by permission of
147 its originator).
148 The full text of the license can be found in the LICENSE file included
150 with this module.
151
153 perl(1)
154 Text::Table .
156
158 Shlomi Fish <shlomif@cpan.org>
159
161 This software is Copyright (c) 2002 by Anno Siegel.
162 This is free software, licensed under:
164 The MIT (X11) License
166perl v5.28.1 2016-04-17 Text::Aligner(3)