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author | JJ | 2023-07-14 16:44:18 +0000 |
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committer | JJ | 2023-07-14 16:44:18 +0000 |
commit | 022b597f56dff2c94fe6aeccd297c294a8348520 (patch) | |
tree | 2d6f50e40defa5390723042d9b689a47cc197259 /entries/omentic/nim | |
parent | 182574d7eecf4d19a94a695c4c60baddaa1758a8 (diff) |
Diffstat (limited to 'entries/omentic/nim')
-rw-r--r-- | entries/omentic/nim/fib.nim | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/entries/omentic/nim/fib.nim b/entries/omentic/nim/fib.nim index a12f8e6..7552e42 100644 --- a/entries/omentic/nim/fib.nim +++ b/entries/omentic/nim/fib.nim @@ -1,12 +1,15 @@ +## standard func fib(n: Natural): Natural = if n < 2: return n else: return fib(n-1) + fib(n-2) +## tail-recursive func fib2(n: int, a = 0, b = 1): int = - return if n == 0: a else: fib2(n-1, b, a+b) + if n == 0: a else: fib2(n-1, b, a+b) +## iterable iterator fib3: int = var a = 0 var b = 1 @@ -15,3 +18,26 @@ iterator fib3: int = swap a, b b += a +## compile-time, list stuff +import std/sugar +static: + proc scan[T, U](list: var seq[T], first, second: U, fun: (U, U) -> U) = + var prev = (first, second) + for i, elem in list: + list[i] = fun(prev[0], prev[1]) + prev[0] = prev[1] + prev[1] = list[i] + + proc fib4(n: int): seq[int] = + result = newSeq[int](n) + result.scan(0, 1, (p, c) => p + c) + +## stupid. macro expansions, outputs (0+1)+((0+1)+(0+1)) etc +import std/macros +macro fib5(n: static[int]): untyped = + var a = quote do: 0 + var b = quote do: 1 + for _ in 0 ..< n: + swap a, b + b = infix(a, "+", b) + return a |