Text::Aligner(3) User Contributed Perl Documentation Text::Aligner(3)NAMEText::AlignerSYNOPSIS
use Text::Aligner qw( align);
# Print the words "just a test!" right-justified each on a line:
my @lines = align( 'right', qw( just a test!);
print "$_\n" for @lines;
DESCRIPTIONText::Aligner exports a single function, align(), which is used to
justify strings to various alignment styles. The alignment
specification is the first argument, followed by any number of scalars
which are subject to alignment.
The operation depends on context. In list context, a list of the
justified scalars is returned. In scalar context, the justified
arguments are joined into a single string with newlines appended. The
original arguments remain unchanged. In void context, in-place
justification is attempted. In this case, all arguments must be
lvalues.
Align() also does one level of scalar dereferencing. That is, whenever
one of the arguments is a scalar reference, the scalar pointed to is
aligned instead. Other references are simply stringified. An
undefined argument is interpreted as an empty string without complaint.
Alignment respects colorizing escape sequences a la Term::ANSICOLOR,
which means it knows that thses sequences don't take up space on the
screen.
ALIGNMENT
The first argument of the align() function is an alignment style, a
single scalar.
It can be one of the strings "left", "right", "center", "num", "point",
or "auto", or a regular expression (qr/.../), or a coderef.
A default style of "left" is assumed for every other value, including
"" and undef.
"left", "right" and "center" have the obvious meanings. These can also
be given as numbers 0, 1, and 0.5 respectively. (Other numbers are also
possible, but probably not very useful).
"num", and its synonym "point", specify that the decimal points be
aligned (assumed on the right, unless present). Arbitrary (non-
numeric) strings are also aligned in this manner, so they end up one
column left of the (possibly assumed) decimal point, flush right with
any integers. For the occasional string like "inf", or "-" for missing
values, this may be the right place. A string-only column ends up
right-aligned (unless there are points present).
The "auto" style separates numeric strings (that are composed of "-",
".", and digits in the usual manner) and aligns them numerically.
Other strings are left aligned with the number that sticks out farthest
to the left. This gives left alignment for string-only columns and
numeric alignment for columns of numbers. In mixed columns, strings
are reasonably placed to serve as column headings or intermediate
titles.
With "num" (and "point") it is possible to specify another character
for the decimal point in the form "num(,)". In fact, you can specify
any string after a leading "(", and the closing ")" is optional.
"point(=>)" could be used to align certain pieces of Perl code. This
option is currently not available with "auto" alignment (because
recognition of numbers is Anglo-centric).
If a regular expression is specified, the points are aligned where the
first match of the regex starts. A match is assumed immediately after
the string if it doesn't match.
A regular expression is a powerful way of alignment specification. It
can replace most others easily, except center alignment and, of course,
the double action of "auto".
POSITIONERS
For entirely self-defined forms of alignment, a coderef, also known as
a positioner, can be given instead of an alignment style. This code
will be called once or more times with the string to be aligned as its
argument. It must return two numbers, a width and a position, that
describe how to align a string with other strings.
The width should normally be the length of the string. The position
defines a point relative to the beginning of the string, which is
aligned with the positions given for other strings.
A zero position for all strings results in left alignment, positioning
to the end of the string results in right alignment, and returning half
the length gives center alignment. "num" alignment is realized by
marking the position of the decimal point.
Note that the position you return is a relative measure. Adding a
constant value to all positions results in no change in alignment. It
doesn't have to point inside the string (as in right alignment, where
it points one character past the end of the string).
The first return value of a positioner should almost always be the
length of the given string. It may be useful to ly about the string
length if the string contains escape sequences that occupy no place on
screen.
USAGE
use Text::Aligner qw( align);
align( $style, $str, ...);
$style must be given and must be an alignment specification.
Any number of scalars can follow. An argument that contains a
scalar reference is dereferenced before it is used. In scalar
and list context, the aligned strings are returned. In void
context, the values are aligned in place and must be lvalues.
BUGS
None known as of realease, but...
AUTHOR
Anno Siegel
CPAN ID: ANNO
COPYRIGHT
Copyright (c) 2002 Anno Siegel. All rights reserved. This program is
free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.
SEE ALSOperl(1)
Text::Table
perl v5.14.1 2010-09-11 Text::Aligner(3)
