Phase 6: slurp, spit, read-line, range 3-arg, repeat/cycle/iterate, interleave

Phase 6 Clojure Core Library now complete (except meta):
- T6.3: slurp (alias for file/read)
- T6.4: spit (alias for file/write)
- T6.5: read-line (stdin input)
- T6.6: range with 3 args (start, end, step)
- T6.7: repeat, cycle, iterate (eager implementations)
- T6.9: interleave
- Updated TASKS.md and ROADMAP.md

lib/cljnim_runtime.nim

@@ -1054,6 +1054,80 @@ proc cljRange*(start, finish: CljVal): CljVal =
     items.add(cljInt(i))
   cljList(items)
 
+proc cljRange3*(start, finish, step: CljVal): CljVal =
+  if start.kind != ckInt or finish.kind != ckInt or step.kind != ckInt:
+    raise newException(CatchableError, "range requires integers")
+  if step.intVal == 0: raise newException(CatchableError, "range step cannot be zero")
+  var items: seq[CljVal] = @[]
+  if step.intVal > 0:
+    var i = start.intVal
+    while i < finish.intVal:
+      items.add(cljInt(i))
+      i += step.intVal
+  else:
+    var i = start.intVal
+    while i > finish.intVal:
+      items.add(cljInt(i))
+      i += step.intVal
+  cljList(items)
+
+proc cljRepeat*(n: CljVal, x: CljVal): CljVal =
+  if n.kind != ckInt: raise newException(CatchableError, "repeat requires an integer count")
+  var items: seq[CljVal] = @[]
+  for i in 0..<n.intVal:
+    items.add(x)
+  cljList(items)
+
+proc cljCycle*(n: CljVal, coll: CljVal): CljVal =
+  if n.kind != ckInt: raise newException(CatchableError, "cycle requires an integer count")
+  var srcItems: seq[CljVal] = @[]
+  case coll.kind
+  of ckList: srcItems = coll.listItems
+  of ckVector: srcItems = toSeq(coll.vecData)
+  else: return cljList(@[])
+  if srcItems.len == 0: return cljList(@[])
+  var items: seq[CljVal] = @[]
+  for i in 0..<n.intVal:
+    items.add(srcItems[i mod srcItems.len])
+  cljList(items)
+
+proc cljIterate*(n: CljVal, f: CljVal, x: CljVal): CljVal =
+  if n.kind != ckInt: raise newException(CatchableError, "iterate requires an integer count")
+  if f.kind != ckFn: raise newException(CatchableError, "iterate requires a function")
+  var items: seq[CljVal] = @[x]
+  var current = x
+  for i in 1..<n.intVal:
+    current = f.fnProc(@[current])
+    items.add(current)
+  cljList(items)
+
+proc cljInterleave*(args: seq[CljVal]): CljVal =
+  if args.len < 2: raise newException(CatchableError, "interleave requires at least 2 arguments")
+  var seqs: seq[seq[CljVal]] = @[]
+  for a in args:
+    case a.kind
+    of ckList: seqs.add(a.listItems)
+    of ckVector: seqs.add(toSeq(a.vecData))
+    else: seqs.add(@[])
+  var minLen = seqs[0].len
+  for s in seqs:
+    if s.len < minLen: minLen = s.len
+  var items: seq[CljVal] = @[]
+  for i in 0..<minLen:
+    for s in seqs:
+      items.add(s[i])
+  cljList(items)
+
+proc cljReadLine*(): CljVal =
+  try:
+    var line = ""
+    if readLine(stdin, line):
+      cljString(line)
+    else:
+      cljNil()
+  except EOFError:
+    cljNil()
+
 # ---- File Operations ----
 
 proc cljFileRead*(path: CljVal): CljVal =