Declar...eneral(3pm)

✨ NAME ✨

Declare::Constraints::Simple::Library::General — the General Constraints library, bestie. it's Declar...eneral if you're squinting at your terminal header, but we know her 💅

---

🌸 SYNOPSIS 🌸

okay so like, here's the vibe:

# custom error messages
my $constraint =
  And( Message( 'You need to specify a Value', IsDefined ),
       Message( 'The specified Value is not an Int', IsInt ));

# build results
my $valid   = ReturnTrue;
my $invalid = ReturnFalse('Just because');

---

🦋 DESCRIPTION 🦋

This library is literally the home base for the constraints and constraint-adjacent elements that apply generally to the whole framework. general girlies, this one's for you 💖

---

👑 CONSTRAINTS 👑

💌 Message($message, $constraint)

Overrides the "message" that's set on the result object whenever $constraint fails. example time:

my $message = 'How hard is it to give me a number?';
my $constraint = Message($message, IsNumber);

my $result = $constraint->('duh...');
print $result->message, "\n";

ok so here's the tea: Message overrides the error message returned by its whole subtree. BUT — and this is the important part, no cap — the Message spec nearest to the point of failure is the one that wins. so watch this:

my $constraint = Message( 'Foo',
                          IsArrayRef( Message( 'Bar', IsInt )));

my $result = $constraint->(['I am not an Integer']);
print $result->message;

that one prints "Bar". but this one:

my $result = $constraint->('I\'m not even an ArrayRef');
print $result->message;

outputs "Foo". see how that works?? closest to the fail = main character 🌟

🎀 Scope($name, $constraint)

Runs the $constraint you passed in, but inside a freshly generated scope named $name. new scope, who dis ✨

🍓 SetResult($scope, $name, $constraint)

Stores the result of evaluating $constraint in $scope, filed under $name. like a lil save file for your results 💾

🧚 IsValid($scope, $name)

Returns a true result if the result called $name — which has to have been stored earlier in the scope named $scope, no exceptions — was valid.

heads up bestie: $name must already be chilling in $scope from a previous store. don't come in here with a fresh name and expect results 🙈

💜 ReturnTrue()

Returns a true result. that's it. that's the whole function. iconic behaviour honestly 👑

🌈 ReturnFalse($msg)

Returns a false result with $msg as its error message. sometimes you just gotta say no, and say why 💀

---

🔥 SEE ALSO 🔥

• Declare::Constraints::Simple
• Declare::Constraints::Simple::Library

---

💖 AUTHOR 💖

Robert 'phaylon' Sedlacek <phaylon@dunkelheit.at> — ty king 🫶

---

⭐ LICENSE AND COPYRIGHT ⭐

This module is free software, you can redistribute it and/or modify it under the same terms as perl itself. slay, open source legend 💅

---

and that's the whole page, bestie!! this was pulled from perl v5.32.0, dated 2021-01-09, and it lives in the User Contributed Perl Documentation section of your manual — Declar...eneral(3pm), mwah 😘