orif

["Soni L." <fakedme@...>]

(Copypasted from https://gist.github.com/SoniEx2/99882fa8d5a0740339b0#the-orif-idea )

The orif Idea
=============

orif (possible operators: `|if`, `orif`, `or if`, ...) is a construct that allows if statements with **explicit** fall-through.

Trivial use-case
----------------

Take the following piece of Java:

```java
boolean flag = false;
switch (i) {
    case 1:
        flag = true;
        // fallthrough
    case 2:
        System.out.println(flag)
        break;
    default:
        System.out.println("Unknown!")
}
```

In Lua (there are many ways to do it, I just picked one at random):

```lua
local flag = false
if i == 1 then
    flag = true
end
if i == 1 or i == 2 then
    print(flag)
end
if i ~= 1 and i ~= 2 then
    print "Unknown!"
end
```

With orif:

```lua
local flag = false
if i == 1 then
    flag = true
orif i == 2 then -- explicit fallthrough
    print(flag)
else -- default
    print "Unknown!"
end
```

Differences between orif and switch
-----------------------------------

Here's a list of pros and cons, where we compare speed, flexibility and clarity of switch and orif.

Switch:

- +Essentially jump tables. (speed)
- -Constant cases. (flexibility)
- -Fallthrough-by-default (on most programming languages). (clarity)

Orif:

- -If-else chain. (speed)
- +Lets you test any conditions. (flexibility)
- +Explicit fallthrough. (clarity)

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