sidef/scripts/extend_your_language.sf

#!/usr/bin/ruby

class if2(cond1, cond2) {
    method then(block) {    # both true
        if (self.cond1 && self.cond2) {
            block.run;
        }
        return self;
    }
    method else1(block) {   # first true
        if (self.cond1 && !self.cond2) {
            block.run;
        }
        return self;
    }
    method else2(block) {   # second true
        if (self.cond2 && !self.cond1) {
            block.run;
        }
        return self;
    }
    method else(block) {    # none true
        if (!self.cond1 && !self.cond2) {
            block.run;
        }
        return self;
    }
}

if2(false, true).then {
    say "if2";
}.else1 {
    say "else1";
}.else2 {
    say "else2";        # <- this gets printed
}.else {
    say "else"
}