34 lines
529 B
Forth
34 lines
529 B
Forth
# example program: compute the factorial of 5
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def main [
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local-scope
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x:num <- factorial 5
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$print [result: ], x, [
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]
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]
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def factorial n:num -> result:num [
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local-scope
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load-inputs
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{
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# if n=0 return 1
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zero?:bool <- equal n, 0
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break-unless zero?
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return 1
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}
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# return n * factorial(n-1)
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x:num <- subtract n, 1
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subresult:num <- factorial x
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result <- multiply subresult, n
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]
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# unit test
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scenario factorial-test [
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run [
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1:num <- factorial 5
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]
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memory-should-contain [
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1 <- 120
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]
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]
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