# NAME

PerlX::Let - Syntactic sugar for lexical constants

# VERSION

version v0.2.1

# SYNOPSIS

```perl
use PerlX::Let;

let $x = 1,
    $y = "string" {

    if ( ($a->($y} - $x) > ($b->{$y} + $x) )
    {
      something( $y, $x );
    }

}
```

# DESCRIPTION

This module allows you to define lexical constants using a new `let`
keyword, for example, code such as

```perl
if (defined $arg{username}) {
  $row->update( { username => $arg{username} );
}
```

is liable to typos. You could simplify it with

```perl
let $key = "username" {

  if (defined $arg{$key}) {
    $row->update( { $key => $arg{$key} );
  }

}
```

This is roughly equivalent to using

```perl
use Const::Fast;

{
 const $key => "username";

  if (defined $arg{$key}) {
    $row->update( { $key => $arg{$key} );
  }

}
```

However, if the value does not contain a sigil, and the variable is a
scalar, or you are using Perl v5.28 or later, this uses state
variables so that the value is only set once.

# KNOWN ISSUES

The parsing of assignments is rudimentary, and may fail when assigning
to another variable or the result of a function.

Because this modifies the source code during compilation, the line
numebrs may be changed.

# SEE ALSO

[Const::Fast](https://metacpan.org/pod/Const::Fast)

[Keyword::Simple](https://metacpan.org/pod/Keyword::Simple)

# AUTHOR

Robert Rothenberg <rrwo@cpan.org>

# COPYRIGHT AND LICENSE

This software is Copyright (c) 2019 by Robert Rothenberg.

This is free software, licensed under:

```
The Artistic License 2.0 (GPL Compatible)
```