= Branch =

The branch statement is used to conditionally execute code where there are a range of execution options on a single variable value.

== Grammar ==
{{{
  branch <variable>
    on <value> [or <value>]...
        <statements>
    [on <value> [or <value>]...
        <statements> ]...
    [else
        <statements>]

  branch <variable> 
    on <value>, <statement>
    on <value>, <statement> 
    [else, <statement>]
}}}
The value of variable is evaluated and the '''on''' clause matching the value is evaluated.
If there is no match any '''else''' clause is evaluated

 * What's being branched on must be an integer, character, enumeration or string. 
 * The expressions being matched ( the <value>s ) must be constants (e.g. 0, 1, c'x', State.Off, "foo"). 

The second form is for one line statements and allows the '''on''' value and statement to be on the same line.
Multiple matching values can be specified separated by keyword '''or'''

== Examples ==
{{{
    # Notice the keywords `branch` and 
    # `on` as well as the indentation under each `on` clause
    x = 2 
    branch x 
        on 1 
            isEven = false 
            word = 'one' 
        on 2 
            isEven = true
            word = 'two' 
        on 3 
            isEven = false 
            word = 'three' 
        else
            word='UNKNOWN'
    assert isEven 
    assert word == 'two' 
}}}



If there is only one statement for the `on` or `else` and you want to tighten up your code, you can do so by using a comma (,) after the 'on' clause
and putting the  statement on the same line
{{{
    x = 'toof' 
    branch x 
        on 'woof', word = 'one' 
        on 'doof', word = 'three' 
        else, word = 'else' 
    assert word == 'else'
}}}

You can have more than one value for a single `on` clause 
{{{
    x = 2 
    branch x 
        on 1 or 2 or 3, word = 'number' 
        else, word = 'else' 
    assert word == 'number'
}}}