when_expression 1.0.0

when expression written for Dart

when™ v1.0.0

Overview

• Wanted some functional programming in Dart?
• Realised that the only way not to use ifs and switches is ternary operatiors?

Something has gone wrong

Now Check This!®

How to use this super-awesome super-helpful super-non-flutter-way library©

0. Use pub.dev to get this s-a s-h s-n-f-w library©

dependencies:
  when_expression: ^1.0.0

1. Define when™ statement

final myWhenStatement = when<int, String>({
  (v) => v == 1: (_) => "a",
  (v) => v == 2: (_) => "b",
  (v) => v == 2: (_) => "c",
  (v) => v == 4: (_) => "d",
  (v) => true: (_) => "you're a failure"
});

2. Be aware!

final myWhenStatement = when<int, String>({
  (v) => v == 1: (_) => "a",
  (v) => v == 2: (_) => "b", // This one will work
  (v) => v == 2: (_) => "c", // This one will never be handled
  (v) => v == 4: (_) => "d",
  (v) => true: (_) => "you're a failure" // if your value is not handled if previous parts
                                         // you should define else statement
});

3. Call it!

print("out: ${myWhenStatement(1)}") // out: a
print("out: ${myWhenStatement(2)}") // out: b
print("out: ${myWhenStatement(10000)}") // out: you're a failure

//This won't compile
print("out: ${myWhenStatement('-1.0')}")

Credits:

• My righteous anger at Dart for its so-called simplicity (Really, you've made this wrong, congrats, dart devs!)