Examples: Fix compiling issues and almost all imports

Author: dlesnoff

examples/elliptic.nim

@@ -1,11 +1,15 @@
 # By Cyther606: http://forum.nimrod-lang.org/t/522
 # Adapted from: https://github.com/wobine/blackboard101/blob/master/EllipticCurvesPart4-PrivateKeyToPublicKey.py
-import bigints, math, strutils
+import bigints
+import std/[math, strutils]
+
+const
+  one = 1.initBigInt
 
 proc `^`(base: int; exp: int): BigInt =
   let base = base.initBigInt
   var exp = exp
-  result = 1.initBigInt
+  result = one
   while exp > 0:
     result *= base
     dec(exp)

examples/pidigits.nim

@@ -1,10 +1,19 @@
 # Translation of http://benchmarksgame.alioth.debian.org/u32/program.php?test=pidigits&lang=go&id=4
 
-import os, strutils, unsigned, bigints
+import std/[os, strutils]
+import ../src/bigints
+
+const
+  one = 1.initBigInt
+  zero = 0.initBigInt
+  ten = 10.initBigInt
+  two = 2.initBigInt
+let
+  mask = (one shl 32) - one
 
 var
-  tmp1, tmp2, tmp3, acc, k, dd = initBigInt(0)
-  den, num, k2 = initBigInt(1)
+  tmp1, tmp2, tmp3, acc, k, dd = zero
+  den, num, k2 = one
 
 proc extractDigit(): int32 =
   if num > acc:
@@ -20,16 +29,16 @@ proc extractDigit(): int32 =
   if tmp2 >= den:
     return -1
 
-  result = int32(tmp1.limbs[0])
+  result = cast[int32](tmp1 and mask)
 
 proc eliminateDigit(d: int32) =
-  acc -= den * d
-  acc *= 10
-  num *= 10
+  acc -= den * d.initBigInt
+  acc *= ten
+  num *= ten
 
 proc nextTerm() =
-  k += 1
-  k2 += 2
+  k += one
+  k2 += two
   tmp1 = num shl 1
   acc += tmp1
   acc *= k2

examples/rc_combperm.nim

@@ -1,19 +1,22 @@
 # Solution for http://rosettacode.org/wiki/Combinations_and_permutations
-import bigints
+import ../src/bigints
+
+const
+  zero = 0.initBigInt
 
 proc perm(n, k: int32): BigInt =
   result = initBigInt 1
   var
-    k = n - k
-    n = n
+    k = initBigInt(n - k)
+    n = initBigInt(n)
   while n > k:
     result *= n
     dec n
 
 proc comb(n, k: int32): BigInt =
   result = perm(n, k)
-  var k = k
-  while k > 0:
+  var k = initBigInt(k)
+  while k > zero:
     result = result div k
     dec k
 

examples/rc_godtheinteger.nim

@@ -1,5 +1,5 @@
 # Solution for http://rosettacode.org/wiki/9_billion_names_of_God_the_integer#Python
-import bigints
+import ../src/bigints
 
 var cache = @[@[1.initBigInt]]
 
@@ -14,7 +14,7 @@ proc cumu(n: int): seq[BigInt] =
 proc row(n: int): seq[BigInt] =
   let r = cumu n
   result = @[]
-  for i in 0 .. <n:
+  for i in 0 ..< n:
     result.add r[i+1] - r[i]
 
 echo "rows:"

examples/rc_godtheinteger2.nim

@@ -1,10 +1,12 @@
 # Solution for http://rosettacode.org/wiki/9_billion_names_of_God_the_integer#Python
-import bigints
+import ../src/bigints
 
 var p = @[1.initBigInt]
+const
+  zero = 0.initBigInt
 
 proc partitions(n: int): BigInt =
-  p.add 0.initBigInt
+  p.add zero
 
   for k in 1..n:
     var d = n - k * (3 * k - 1) div 2

examples/rc_hammingnumbers.nim

@@ -1,27 +1,33 @@
 # Translation of http://rosettacode.org/wiki/Hamming_numbers#Another_implementation_of_same_approach
 
-import bigints, math
+import ../src/bigints
+import std/math
+
+const
+  two = initBigInt(2)
+  three = initBigInt(3)
+  five = initBigInt(5)
 
 proc hamming(limit: int): BigInt =
   var
     h = newSeq[BigInt](limit)
-    x2 = initBigInt(2)
-    x3 = initBigInt(3)
-    x5 = initBigInt(5)
+    x2 = two
+    x3 = three
+    x5 = five
     i, j, k = 0
   for i in 0..h.high: h[i] = initBigInt(1)
 
-  for n in 1 .. < limit:
+  for n in 1 ..< limit:
     h[n] = min([x2, x3, x5])
     if x2 == h[n]:
       inc i
-      x2 = h[i] * 2
+      x2 = h[i] * two
     if x3 == h[n]:
       inc j
-      x3 = h[j] * 3
+      x3 = h[j] * three
     if x5 == h[n]:
       inc k
-      x5 = h[k] * 5
+      x5 = h[k] * five
 
   result = h[h.high]
 

examples/rc_integersequence.nim

@@ -1,6 +1,7 @@
-import bigints
+import ../src/bigints
 
+let one = 1.initBigInt
 var i = 0.initBigInt
 while true:
-  i += 1
+  i += one
   echo i

examples/rc_leftfactorials.nim

@@ -1,16 +1,21 @@
-import iterutils, bigints
+import iterutils
+import ../src/bigints
+
+const
+  one = 1.initBigInt
+  zero = 0.initBigInt
 
 proc lfact: iterator: BigInt =
   result = iterator: BigInt =
-    yield 0.initBigInt
+    yield zero
     var
-      fact = 1.initBigInt
-      sum = 0.initBigInt
-      n = 1.initBigInt
+      fact = one
+      sum = zero
+      n = one
     while true:
       sum += fact
       fact *= n
-      n += 1
+      n += one
       yield sum
 
 echo "first 11:"

examples/rc_modexp.nim

@@ -1,20 +1,27 @@
 # Solution for http://rosettacode.org/wiki/Modular_exponentiation
 
-import bigints
+import ../src/bigints
+
+const
+  zero = 0.initBigInt
+  one = 1.initBigInt
+  two = 2.initBigInt
 
 proc powmod(b, e, m: BigInt): BigInt =
-  assert e >= 0
+  assert e >= zero
   var e = e
   var b = b
-  result = initBigInt(1)
-  while e > 0:
-    if e mod 2 == 1:
+  result = one
+  while e > zero:
+    if e mod two == one:
       result = (result * b) mod m
-    e = e div 2
+    e = e div two
     b = (b.pow 2) mod m
 
 var
   a = initBigInt("2988348162058574136915891421498819466320163312926952423791023078876139")
   b = initBigInt("2351399303373464486466122544523690094744975233415544072992656881240319")
+  res = powmod(a, b, initBigInt(10).pow 40)
 
-echo powmod(a, b, 10.pow 40)
+echo res
+doAssert("1527229998585248450016808958343740453059".initBigInt == res)

examples/rc_paraffins.nim

@@ -1,5 +1,5 @@
 # Solution for http://rosettacode.org/wiki/Paraffins
-import bigints
+import ../src/bigints
 
 const
   nMax: int32 = 250
@@ -15,7 +15,7 @@ for i in 2 .. nMax:
 proc choose(m: BigInt, k: int32): BigInt =
   result = m
   if k == 1: return
-  for i in 1 .. < k:
+  for i in 1 ..< k:
     result = result * (m + i) div (i + 1)
 
 proc tree(br, n, l, sum: int32, cnt: BigInt) =

examples/rc_pidigits.nim

@@ -1,10 +1,20 @@
 # Solution for http://rosettacode.org/wiki/Pi
 
-import strutils, unsigned, bigints
+import std/strutils
+import ../src/bigints
+
+const
+  one = 1.initBigInt
+  zero = 0.initBigInt
+  ten = 10.initBigInt
+  two = 2.initBigInt
+
+let
+  mask = (one shl 32) - one
 
 var
-  tmp1, tmp2, tmp3, acc, k, dd = initBigInt(0)
-  den, num, k2 = initBigInt(1)
+  tmp1, tmp2, tmp3, acc, k, dd = zero
+  den, num, k2 = one
 
 proc extractDigit(): int32 =
   if num > acc:
@@ -20,16 +30,16 @@ proc extractDigit(): int32 =
   if tmp2 >= den:
     return -1
 
-  result = int32(tmp1.limbs[0])
+  result = cast[int32](tmp1 and mask)
 
 proc eliminateDigit(d: int32) =
-  acc -= den * d
-  acc *= 10
-  num *= 10
+  acc -= den * d.initBigInt
+  acc *= ten
+  num *= ten
 
 proc nextTerm() =
-  k += 1
-  k2 += 2
+  k += one
+  k2 += two
   tmp1 = num shl 1
   acc += tmp1
   acc *= k2

examples/rc_pow.nim

@@ -1,8 +1,11 @@
 # Solution for http://rosettacode.org/wiki/Arbitrary-precision_integers_(included)
 
-import bigints
+import ../src/bigints
+import std/math
 
-var x = 5.pow 4.pow 3.pow 2
+let five = 5.initBigInt
+
+var x = five.pow (4 ^ (3 ^ 2)).int32
 var s = $x
 
 echo s[0..19]

examples/rc_sum35.nim

@@ -1,16 +1,22 @@
-import bigints
+import ../src/bigints
+
+const
+  one = 1.initBigInt
+  two = 2.initBigInt
+  ten = 10.initBigInt
 
 proc sumMults(first: int32, limit: BigInt): BigInt =
-  var last = limit - 1
+  var last = limit - one
+  var first = first.initBigInt
   last -= last mod first
-  (last div first) * (last + first) div 2
+  (last div first) * (last + first) div two
 
 proc sum35(n: BigInt): BigInt =
   result = sumMults(3, n)
   result += sumMults(5, n)
   result -= sumMults(15, n)
 
-var x = 1.initBigInt
+var x = one
 while x < "1000000000000000000000000000000".initBigInt:
   echo sum35 x
-  x *= 10
+  x *= ten