NAME
String::Errf - a simple sprintf-like dialect
VERSION
version 0.004
SYNOPSIS
use String::Errf qw(errf);
print errf "This process was started at %{start}t with %{args;argument}n.\n",
{ start => $^T, args => 0 + @ARGV };...might print something like:
This process was started at 2010-10-17 14:05:29 with 0 arguments.DESCRIPTION
String::Errf provides errf, a simple string formatter that works something like sprintf. It is implemented using String::Formatter and Sub::Exporter. Their documentation may be useful in understanding or extending String::Errf.
DIFFERENCES FROM SPRINTF
The data passed to errf should be organized in a single hashref, not a list.
Formatting codes require named parameters, and the available codes are different. See "FORMATTING CODES" below.
As with most String::Formatter formatters, % is not a format code. If you want a literal %, do not put anything between the two percent signs, just write %%.
FORMATTING CODES
errf formatting codes require a set of arguments between the % and the formatting code letter. These arguments are placed in curly braces and separated by semicolons. The first argument is the name of the data to look for in the format data. For example, this is a valid use of errf:
errf "The current time in %{tz}s is %{now;local}t.", {
tz => $ENV{TZ},
now => time,
};The second argument, if present, may be a compact form for multiple named arguments. The rest of the arguments will be named values in the form name=value. The examples below should help clarify how arguments are passed. When an argument appears in both a compact and named form, the named form trumps the compact form.
The specific codes and their arguments are:
s for string
The s format code is for any string, and takes no arguments. It just includes the named item from the input data.
errf "%{name}s", { name => 'John Smith' }; # returns "John Smith"Remember, errf does not have any of the left- or right-padding formatting that sprintf provides. It is not meant for building tables, only strings.
i for integer
The i format code is used for integers. It takes one optional argument, prefix, which defaults to the empty string. prefix may be given as the compact argument, standing alone. prefix is used to prefix non-negative integers. It may only be a plus sign.
errf "%{x}i", { x => 10 }; # returns "10"
errf "%{x;+}i", { x => 10 }; # returns "+10"
errf "%{x;prefix=+}i", { x => 10 }; # returns "+10"The rounding behavior for non-integer values is not currently specified.
f for float (or fractional)
The f format code is for numbers with sub-integer precision. It works just like i, but adds a precision argument which specifies how many decimal places of precision to display. The compact argument may be just the prefix or the prefix followed by a period followed by the precision.
errf "%{x}f", { x => 10.1234 }; # returns "10";
errf "%{x;+}f", { x => 10.1234 }; # returns "+10";
errf "%{x;.2}f", { x => 10.1234 }; # returns "10.12";
errf "%{x;+.2}f", { x => 10.1234 }; # returns "+10.12";
errf "%{x;precision=.2}f", { x => 10.1234 }; # returns "10.12";
errf "%{x;prefix=+;precision=.2}f", { x => 10.1234 }; # returns "+10.12";t for time
The t format code is used to format timestamps provided in epoch seconds. It can be given two arguments: type and tz.
type can be either date, time, or datetime, and indicates what part of the timestamp should be displayed. The default is datetime. tz requests that the timestamp be displayed in either UTC or the local time zone. The default is local.
The compact form is just type alone.
# Assuming our local time zone is America/New_York...
errf "%{x}t", { x => 1280530906 }; # "2010-07-30 19:01:46"
errf "%{x;type=date}t", { x => 1280530906 }; # "2010-07-30"
errf "%{x;type=time}t", { x => 1280530906 }; # "19:01:46"
errf "%{x;type=datetime}t", { x => 1280530906 }; # "2010-07-30 19:01:46"
errf "%{x;tz=UTC}t", { x => 1280530906 }; # "2010-07-30 23:01:46 UTC"
errf "%{x;tz=UTC;type=date}t", { x => 1280530906 }; # "2010-07-30 UTC"
errf "%{x;tz=UTC;type=time}t", { x => 1280530906 }; # "23:01:46 UTC"
errf "%{x;tz=UTC;type=datetime}t", { x => 1280530906 }; # "2010-07-30 23:01:46 UTC"n and N for numbered
The n and N format codes are for picking words based on number. It takes two of its own arguments, singular and plural, as well as prefix and precision which may be used for formatting the number itself.
If the value being formatted is 1, the singular word is used. Otherwise, the plural form is used.
errf "%{x;singular=dog;plural=dogs}n", { x => 0 }; # 0 dogs
errf "%{x;singular=dog;plural=dogs}n", { x => 1 }; # 1 dog
errf "%{x;singular=dog;plural=dogs}n", { x => 2 }; # 2 dogs
errf "%{x;singular=dog;plural=dogs}n", { x => 1.4 }; # 1.4 dogs
errf "%{x;singular=dog;plural=dogs;precision=1}n", { x => 1.4 }; # 1.4 dogs
errf "%{x;singular=dog;plural=dogs;precision=0}n", { x => 1.4 }; # 1 dogIf N is used instead of n, the number will not be included, only the chosen word.
errf "%{x;singular=is;plural=are}N", { x => 0 }; # are
errf "%{x;singular=is;plural=are}N", { x => 1 }; # is
errf "%{x;singular=is;plural=are}N", { x => 2 }; # are
errf "%{x;singular=is;plural=are}N", { x => 1.4 }; # 1.4 are
errf "%{x;singular=is;plural=are;precision=1}N", { x => 1.4 }; # 1.4 are
errf "%{x;singular=is;plural=are;precision=0}N", { x => 1.4 }; # 1 isThe compact form may take any of the following forms:
word - equivalent to singular=word
word+suffix - equivalent to singular=word;plural=wordsuffix
word1/word2 - equivalent to singular=word;plural=word2If no singular form is given, an exception is thrown. If no plural form is given, one will be generated according to some basic rules of English noun orthography.
AUTHOR
Ricardo Signes <rjbs@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2010 by Ricardo Signes.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.