Conditionals:

“If” statements have the following structure:

if {expression is truthy} then
    # ...
elif {expression is truthy} then
    # ...
else
    # ...
end

You can also leave out the “then” clause if all that’s needed is the “else” clause, e.g.:

if {expression is truthy} else
    # ... do this if expression is falsey ...
end

Keep in mind that if statements convert the expression to a boolean, and so use a few rules to test an expression’s truthiness: false, null, zero, empty strings, empty arrays and empty objects are all falsey, everything else is truthy. See the type-casting docs for more info on truthiness and other type-casting rules.

There is also the match structure, which is similar to c-like languages’ switch/case structure (or Rust’s match). This structure is included to allow for more readable logic with less repeated code.

match {expression} do
    action1 if {case 1}
    action2 if {case 2}
    if {case 3} then #[[...complex logic, loops, etc...#]] end
    # ...
else
    # ... default action if no cases match ...
end

For example:

match {random_int(1,5)} do
    print one if 1
    print two if 2
    print "4 or 5" if {> 4}
    if {like '%d+'} then error "it's a string?!" end
else
    print "some other number"
end

See how there are two possible syntaxes for the match branches. The first kind, {command(s)} if {expression} only allows a list of simple commands, that is, any block statements (e.g. if, while, etc.)are not allowed, however, multiple commands are fine (e.g. print 123; stop if {> 4} is fine). The second kind, if {expression} then {command(s)} end functions like a normal if statement; it allows any kind of statement(s) to be used inside.

Note that, inside match statements, the top-level boolean operators (=, !=, >, <, >=, <=, in, like, and, or, xor, %%) and bitwise operators (bitwise and, bitwise or, bitwise xor) don’t require a left operand. Instead, the left operand is implied to be the bound value of the match expression. If the operator is left out, then = is implied. e.g. {3} is the same as {=3}.

Of course, like if statements, the else branch is optional and can be excluded.

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