trizen / island

The Island programming language. (unimplemented idea)

Island

The Island programming language is a an experimental project for a uniformly design programming language.

The main features of the language include:

• Prefix notation
• Multiple dispatch
• Higher-order functions
• Uniformity and simplicity

Examples

The following examples illustrate some of the decisions made in designing the syntax of the language.

Factorial

def fac { |n|
    if [eq n 0] [ return 1 ]
    mul n (call fac (sub n 1))
}

say (call fac 10)    #=> 3628800

Fibonacci

def fib { |n|
    if [lt n 2] [ return n ]
    add (call fib (sub n 1)) (call fib (sub n 2))
}

say (call fib 12)    #=> 144

Bernoulli numbers (recursive)

def bern_helper { |n k|
    mul (call binomial n k) (div (call bernoulli_number k) (add (sub n k) 1))
}

def bern_diff { |n k d|
    if [lt n k] [ return d ]
    call bern_diff n (add k 1) (sub d (call bern_helper (add n 1) k))
}

def bernoulli_number { |n|
    if [one? n] [ return (div 1 2) ]
    if [odd? n] [ return 0         ]
    if [gt n 0] [ return (call bern_diff (sub n 1) 0 1) ]
    return 1
}

for (range 0 25) { |i|
    def num (call bernoulli_number i)
    unless [zero? num] [
        printf "B(%2d) = %20s / %s\n" i (nu num) (de num)
    ]
}

while-loop

Multimethod: while(Expr, Expr)

def n 10
while [gt n 0] [
    say n
    sub! n 1
]

foreach-loop

Multimethod: for(Range, Block)

for (range 1 10) { |n|
    say n
}

for(;;)-loop

Multimethod: for(Expr, Expr, Expr, Expr)

for [def n 1] [lt n 10] [add! n 1] [
    say n
]