Listack program examples

Examples of different ways to do the same thing in Listack.

10 @>n # set local variable n to 10

# The following all set the variable a to (n+1)2 → 22.

n 1 .+ 2 . @>a

n + 1 2 @>a

(n + 1 2) @>a

(n + 1) 2 @>a

n.inc 2 @>a

set(‘a’, (n + 1 2))

set: `a (n + 1 2)

“a” set (+: n 1 2)

a (n 1 .+ 2 .) .set

set(a, (+(n, 1), 2))

set(a (+(n 1) 2))

a set (+: @<n 1 2 .)

n.get 1 .+ 2 . @>a

{n + 1 2} eval @>a

+: @n 1 2 a swap .set

# And many more, with increasing levels of obfuscation.

Computing the summation of 0..number

def: "summ" [Int]

{dup <=> # would be a bit faster if this were postfix

{dup {1 .+ dup 0 .<} {dup roll .+ swap} .while} # negative

{dup} # zero

{dup {1 .- dup 0 .>} {dup roll .+ swap} .while} # positive

drop }

timerstart 100000 summ timercheck # timer works in nanoseconds

"summ(100,000) time: " print 1000000 .// print " ms" println

println cr

def: "fastsumm" [Int]

{ dup # <=> This is a good way to indicate what’s going on with postfix words.

{dup 1 .- . -2 .//}

{nop}

{dup 1 .+ . 2 .//}

.<=> }

timerstart 100000 fastsumm timercheck

"fastsumm(100,000) time: " print 1000 .// print " us" println

println