NAME

       Text::sprintfn - Drop-in replacement for sprintf(), with named parameter support

VERSION

       This document describes version 0.08 of Text::sprintfn (from Perl distribution Text-
       sprintfn), released on 2015-09-15.

SYNOPSIS

        use Text::sprintfn; # by default exports sprintfn() and printfn()

        # with no hash, behaves just like printf
        printfn '<%04d>', 1, 2; # <0001>

        # named parameter
        printfn '<%(v1)-4d>', {v1=>-2}; # <-2  >

        # mixed named and positional
        printfn '<%d> <%(v1)d> <%d>', {v1=>1}, 2, 3; # <2> <1> <3>

        # named width
        printfn "<%(v1)(v2).1f>", {v1=>3, v2=>4}; # <   3>

        # named precision
        printfn "<%(v1)(v2).(v2)f>", {v1=>3, v2=>4}; # <3.0000>

DESCRIPTION

       This module provides sprintfn() and printfn(), which are like sprintf() and printf(), with
       the exception that they support named parameters from a hash.

FUNCTIONS

   sprintfn $fmt, \%hash, ...
       If first argument after format is not a hash, sprintfn() will behave exactly like
       sprintf().

       If hash is given, sprintfn() will look for named parameters in argument and supply the
       values from the hash. Named parameters are surrounded with parentheses, i.e. "(NAME)".
       They can occur in format parameter index:

        %2$d        # sprintf version, take argument at index 2
        %(two)d     # $ is optional
        %(two)$d    # same

       or in width:

        %-10d       # sprintf version, use (minimum) width of 10
        %-(width)d  # like sprintf, but use width from hash key 'width'
        %(var)-(width)d  # format hash key 'var' with width from hash key 'width'

       or in precision:

        %6.2f       # sprintf version, use precision of 2 decimals
        %6.(prec)f  # like sprintf, but use precision from hash key 'prec'
        %(width).(prec)f
        %(var)(width).(prec)f

       The existence of formats using hash keys will not affect indexes of the rest of the
       argument, example:

        sprintfn "<%(v1)s> <%2$d> <%d>", {v1=>10}, 0, 1, 2; # "<10> <2> <0>"

       Like sprintf(), if format is unknown/erroneous, it will be printed as-is.

       There is currently no way to escape ")" in named parameter, e.g.:

        %(var containing ))s

   printfn $fmt, ...
       Equivalent to: print sprintfn($fmt, ...).

RATIONALE

       There exist other CPAN modules for string formatting with named parameter support. Two of
       such modules are String::Formatter and Text::Sprintf::Named. This module is far simpler to
       use and retains all of the features of Perl's sprintf() (which we like, or perhaps hate,
       but nevertheless are familiar with).

       String::Formatter requires you to create a new formatter function first.
       Text::Sprintf::Named also accordingly requires you to instantiate an object first. There
       is currently no way to mix named and positional parameters. And you don't get the full
       features of sprintf().

HOW IT WORKS

       Text::sprintfn works by converting the format string into sprintf format, i.e.  replacing
       the named parameters like "%(foo)s" to something like "%11$s".

DOWNSIDES

       Currently the main downside is speed. "sprintfn()" is about 2-3 orders of magnitude slower
       than "sprintf()". A sample benchmark:

                                                       Rate sprintfn("%(a)s%(b)d%(c)f",{..}) 1k sprintfn("%(a)s",{a=>1}) 1k sprintfn("%s",1) 1k sprintf ("%s%d%f",1,2,3) 1k sprintf ("%s",1) 1k
        sprintfn("%(a)s%(b)d%(c)f",{..}) 1k 45.354+-0.084/s                                  --                      -58.7%              -97.3%                      -99.9%              -99.9%
        sprintfn("%(a)s",{a=>1}) 1k          109.82+-0.14/s                       142.13+-0.54%                          --              -93.4%                      -99.7%              -99.7%
        sprintfn("%s",1) 1k                  1672.62+-0.6/s                          3587.9+-7%                  1423.1+-2%                  --                      -96.1%              -96.2%
        sprintf ("%s%d%f",1,2,3) 1k             42658+-12/s                         93950+-180%                  38744+-50%             2450.4%                          --               -2.2%
        sprintf ("%s",1) 1k                     43596+-48/s                         96020+-210%                  39599+-66%          2506.5+-3%                  2.2+-0.12%                  --

TIPS AND TRICKS

   Common mistake 1
       Writing

        %(var)

       instead of

        %(var)s

   Common mistake 2 (a bit more newbish)
       Writing

        sprintfn $format, %hash, ...;

       instead of

        sprintfn $format, \%hash, ...;

   Alternative hashes
       You have several hashes (%h1, %h2, %h3) which should be consulted for values.  You can
       either merge the hash first:

        %h = (%h1, %h2, %h3); # or use some hash merging module
        printfn $format, \%h, ...;

       or create a tied hash which can consult hashes for you:

        tie %h, 'Your::Module', \%h1, \%h2, \%h3;
        printfn $format, \%h, ...;

SEE ALSO

       sprintf() section on perlfunc

       String::Formatter

       Text::Sprintf::Named

HOMEPAGE

       Please visit the project's homepage at <https://metacpan.org/release/Text-sprintfn>.

SOURCE

       Source repository is at <https://github.com/perlancar/perl-Text-sprintfn>.

BUGS

       Please report any bugs or feature requests on the bugtracker website
       <https://rt.cpan.org/Public/Dist/Display.html?Name=Text-sprintfn>

       When submitting a bug or request, please include a test-file or a patch to an existing
       test-file that illustrates the bug or desired feature.

AUTHOR

       perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2015 by perlancar@cpan.org.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.