Conditionals

The simplest form of a conditional construction is:

if cond do
   stmts
 elif cond do
   stmts
 ...
 else
   stmts
 done

The elif and else clauses are optional. The final done does not require a trailing semicolon. The construction is sugar for a collection of labels and gotos, so that it is ok to put labels in the controlled statements and jump into the middle of a conditional with a goto.

A simplified form is drives a single statement:

if cond perform stuff;

A more advanced statement is:

match expr with
| pattern1 => stmts1
| pattern2 => stmts2
...
endmatch;

The final endmatch and semicolon is mandatory to distinguish the construction from a match expression. If none of the pattern match the program aborts with a match failure exception.