make countup et al take only a single type parameter in order to prevent type guesses

lib/pure/mersenne.nim

@@ -17,7 +17,7 @@ type
 proc newMersenneTwister*(seed: uint32): MersenneTwister =
   result.index = 0
   result.mt[0] = seed
-  for i in 1..623'u32:
+  for i in 1'u32 .. 623'u32:
     result.mt[i] = (0x6c078965'u32 * (result.mt[i-1] xor (result.mt[i-1] shr 30'u32)) + i)
 
 proc generateNumbers(m: var MersenneTwister) =

lib/pure/strscans.nim

@@ -563,12 +563,12 @@ macro scanp*(input, idx: typed; pattern: varargs[untyped]): bool =
     of nnkCurlyExpr:
       if it.len == 3 and it[1].kind == nnkIntLit and it[2].kind == nnkIntLit:
         var h = newTree(nnkPar, it[0])
-        for count in 2..it[1].intVal: h.add(it[0])
+        for count in 2i64 .. it[1].intVal: h.add(it[0])
         for count in it[1].intVal .. it[2].intVal-1: h.add(newTree(nnkPrefix, ident"?", it[0]))
         result = atm(h, input, idx, attached)
       elif it.len == 2 and it[1].kind == nnkIntLit:
         var h = newTree(nnkPar, it[0])
-        for count in 2..it[1].intVal: h.add(it[0])
+        for count in 2i64 .. it[1].intVal: h.add(it[0])
         result = atm(h, input, idx, attached)
       else:
         error("invalid pattern")

lib/system.nim

@@ -1985,7 +1985,8 @@ iterator countdown*[T](a, b: T, step = 1): T {.inline.} =
       yield res
       dec(res, step)
 
-iterator countup*[T](a, b: T, step = 1): T {.inline.} =
+when defined(nimNewRoof):
+  iterator countup*[T](a, b: T, step = 1): T {.inline.} =
     ## Counts from ordinal value `a` up to `b` (inclusive) with the given
     ## step count. `S`, `T` may be any ordinal type, `step` may only
     ## be positive. **Note**: This fails to count to ``high(int)`` if T = int for
@@ -2001,7 +2002,7 @@ iterator countup*[T](a, b: T, step = 1): T {.inline.} =
         yield res
         inc(res, step)
 
-iterator `..`*[T](a, b: T): T {.inline.} =
+  iterator `..`*[T](a, b: T): T {.inline.} =
     ## An alias for `countup`.
     when T is IntLikeForCount:
       var res = int(a)
@@ -2013,6 +2014,36 @@ iterator `..`*[T](a, b: T): T {.inline.} =
       while res <= b:
         yield res
         inc(res)
+else:
+  iterator countup*[S, T](a: S, b: T, step = 1): T {.inline.} =
+    ## Counts from ordinal value `a` up to `b` (inclusive) with the given
+    ## step count. `S`, `T` may be any ordinal type, `step` may only
+    ## be positive. **Note**: This fails to count to ``high(int)`` if T = int for
+    ## efficiency reasons.
+    when T is IntLikeForCount:
+      var res = int(a)
+      while res <= int(b):
+        yield T(res)
+        inc(res, step)
+    else:
+      var res: T = T(a)
+      while res <= b:
+        yield res
+        inc(res, step)
+
+  iterator `..`*[S, T](a: S, b: T): T {.inline.} =
+    ## An alias for `countup`.
+    when T is IntLikeForCount:
+      var res = int(a)
+      while res <= int(b):
+        yield T(res)
+        inc(res)
+    else:
+      var res: T = T(a)
+      while res <= b:
+        yield res
+        inc(res)
+
 
 iterator `||`*[S, T](a: S, b: T, annotation=""): T {.
   inline, magic: "OmpParFor", sideEffect.} =
@@ -3433,7 +3464,14 @@ template `..<`*(a, b: untyped): untyped =
   ## a shortcut for 'a..pred(b)'.
   a .. pred(b)
 
-iterator `..<`*[T](a, b: T): T =
+when defined(nimNewRoof):
+  iterator `..<`*[T](a, b: T): T =
+    var i = T(a)
+    while i < b:
+      yield i
+      inc i
+else:
+  iterator `..<`*[S, T](a: S, b: T): T =
     var i = T(a)
     while i < b:
       yield i