#
# Copyright (c) 2014-2015 Christian Jaeger, copying@christianjaeger.ch
#
# This is free software, offered under either the same terms as perl 5
# or the terms of the Artistic License version 2 or the terms of the
# MIT License (Expat version). See the file COPYING.md that came
# bundled with this file.
#

=head1 NAME

FP::Div - various pure functions

=head1 SYNOPSIS

=head1 DESCRIPTION


=head1 NOTE

This is alpha software! Read the package README.

=cut


package FP::Div;
@ISA="Exporter"; require Exporter;
@EXPORT=qw();
@EXPORT_OK=qw(inc dec square
              identity
              min max minmax
              Chomp
              );
%EXPORT_TAGS=(all=>[@EXPORT,@EXPORT_OK]);

use strict; use warnings; use warnings FATAL => 'uninitialized';
use Chj::TEST;

# XX should `indentity` pass multiple values, and this be called
# `identity_scalar`? :

sub identity ($) {
    @_==1 or die "wrong number of arguments";
    $_[0]
}

sub inc ($) {
    @_==1 or die "wrong number of arguments";
    $_[0] + 1
}

sub dec ($) {
    @_==1 or die "wrong number of arguments";
    $_[0] - 1
}

sub square ($) {
    @_==1 or die "wrong number of arguments";
    $_[0] * $_[0]
}

sub min {
    my $x=shift;
    for (@_) {
        $x= $_ if $_ < $x
    }
    $x
}

sub max {
    my $x=shift;
    for (@_) {
        $x= $_ if $_ > $x
    }
    $x
}

sub minmax {
    my $min=shift;
    my $max=$min;
    for (@_) {
        $min= $_ if $_ < $min;
        $max= $_ if $_ > $max;
    }
    ($min,$max)
}



# is there any better idea than ucfirst to distinguish from the
# builtin? `fchomp` ?
sub Chomp ($) {
    @_==1 or die "wrong number of arguments";
    my ($str)=@_;
    chomp $str;
    $str
}

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