diff --git a/lib/cljnim_pvec.nim b/lib/cljnim_pvec.nim
index 755b9b6..e65bc1e 100644
--- a/lib/cljnim_pvec.nim
+++ b/lib/cljnim_pvec.nim
@@ -77,17 +77,13 @@ proc pushLeaf[T](node: PVecNode[T], index: int, shift: int, val: seq[T]): PVecNo
   # Push a full leaf (seq of up to 32 values) into the tree at position 'index'
   result = copyNode(node)
   if shift == 0:
-    # Should not happen — we always push into internal nodes
     result = newLeafNode[T](val)
   else:
     let childIdx = (index shr shift) and BRANCHING_MASK
-    if childIdx >= result.children.len:
-      # Need to grow children array
-      let oldLen = result.children.len
-      result.children.setLen(childIdx + 1)
-      for i in oldLen..<childIdx:
-        result.children[i] = nil
-    
+    # Grow children array and fill any gaps with empty internal nodes
+    while result.children.len <= childIdx:
+      result.children.add(newInternalNode[T]())
+
     var child = result.children[childIdx]
     if child.isNil:
       if shift == BRANCHING_BITS:
@@ -96,7 +92,7 @@ proc pushLeaf[T](node: PVecNode[T], index: int, shift: int, val: seq[T]): PVecNo
         child = pushLeaf(newInternalNode[T](), index, shift - BRANCHING_BITS, val)
     else:
       child = pushLeaf(child, index, shift - BRANCHING_BITS, val)
-    
+
     result.children[childIdx] = child
 
 proc pvecConj*[T](v: PersistentVector[T], val: T): PersistentVector[T] =
diff --git a/src/core.nim b/src/core.nim
index 280ca4b..0c6a187 100644
--- a/src/core.nim
+++ b/src/core.nim
@@ -277,7 +277,7 @@ proc cljConj*(coll: CljVal, item: CljVal): CljVal =
   of ckVector:
     var newItems = coll.listItems
     newItems.add(item)
-    cljList(newItems)
+    cljVector(newItems)
   else:
     cljList(@[item])
 
@@ -315,11 +315,11 @@ proc cljSeq*(v: CljVal): CljVal =
   else: cljNil()
 
 proc cljVec*(v: CljVal): CljVal =
-  if v.isNil: return cljList(@[])
+  if v.isNil: return cljVector(@[])
   case v.kind
-  of ckList: cljList(v.listItems)
+  of ckList: cljVector(v.listItems)
   of ckVector: v
-  else: cljList(@[v])
+  else: cljVector(@[v])
 
 proc cljEmpty*(v: CljVal): CljVal =
   cljBool(cljCount(v) == 0)
@@ -430,18 +430,39 @@ proc cljType*(v: CljVal): CljVal =
   of ckList: cljKeyword("list")
   of ckVector: cljKeyword("vector")
   of ckMap: cljKeyword("map")
+  of ckSet: cljKeyword("set")
   of ckFn: cljKeyword("function")
   of ckAtom: cljKeyword("atom")
+  of ckTransient: cljKeyword("transient")
+  of ckAgent: cljKeyword("agent")
 
 proc cljMinMax*(args: seq[CljVal], isMin: bool): CljVal =
   if args.len == 0: raise newException(CatchableError, "min/max requires at least 1 argument")
   result = args[0]
   for i in 1..<args.len:
-    if args[i].kind == ckInt and result.kind == ckInt:
+    let a = args[i]
+    if a.kind == ckInt and result.kind == ckInt:
       if isMin:
-        if args[i].intVal < result.intVal: result = args[i]
+        if a.intVal < result.intVal: result = a
       else:
-        if args[i].intVal > result.intVal: result = args[i]
+        if a.intVal > result.intVal: result = a
+    elif a.kind == ckFloat and result.kind == ckFloat:
+      if isMin:
+        if a.floatVal < result.floatVal: result = a
+      else:
+        if a.floatVal > result.floatVal: result = a
+    elif a.kind == ckInt and result.kind == ckFloat:
+      let af = a.intVal.float64
+      if isMin:
+        if af < result.floatVal: result = a
+      else:
+        if af > result.floatVal: result = a
+    elif a.kind == ckFloat and result.kind == ckInt:
+      let rf = result.intVal.float64
+      if isMin:
+        if a.floatVal < rf: result = a
+      else:
+        if a.floatVal > rf: result = a
 
 proc cljAbs*(v: CljVal): CljVal =
   case v.kind
diff --git a/src/emitter.nim b/src/emitter.nim
index 4184917..8320b5e 100644
--- a/src/emitter.nim
+++ b/src/emitter.nim
@@ -2394,6 +2394,13 @@ proc emitProgramInternal(forms: seq[CljVal]): string =
   scopeStack = @[]
   pushScope()
   requiredImports = initHashSet[string]()
+  loopStack = @[]
+  loopResultVar = ""
+  nsAliases = @[]
+  libNsPrefixes = @[]
+  definedGlobals = initHashSet[string]()
+  definedFnArities = initTable[string, int]()
+  multiArityFns = initHashSet[string]()
   var headerLines: seq[string] = @[
     "# Generated by Bara Lang",
     "import cljnim_runtime",
diff --git a/src/eval.nim b/src/eval.nim
index 62cbaad..e1dbe5d 100644
--- a/src/eval.nim
+++ b/src/eval.nim
@@ -725,9 +725,10 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
         coll = args[2]
       else:
         coll = args[1]
-        if coll.kind in {ckList, ckVector} and coll.items.len > 0:
+        if coll.kind in {ckList, ckVector}:
+          if coll.items.len == 0:
+            return EvalResult(ok: false, error: "reduce of empty collection with no initial value")
           acc = coll.items[0]
-          # reduce rest
           var res = acc
           for i in 1..<coll.items.len:
             let callItems = @[fn, res, coll.items[i]]
@@ -920,12 +921,6 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
         of ckAgent: "agent"
       return EvalResult(ok: true, value: cljKeyword(typeName))
 
-    of "not":
-      numArgs(1)
-      let isFalsy = args[0].kind == ckNil or
-        (args[0].kind == ckBool and not args[0].boolVal)
-      return EvalResult(ok: true, value: cljBool(isFalsy))
-
     of "abs":
       numArgs(1)
       if args[0].kind == ckInt:
@@ -953,7 +948,7 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
       if args[0].kind == ckInt and args[1].kind == ckInt:
         if args[1].intVal == 0:
           return EvalResult(ok: false, error: "Division by zero")
-        return EvalResult(ok: true, value: cljInt(args[0].intVal mod args[1].intVal))
+        return EvalResult(ok: true, value: cljInt(args[0].intVal - (args[0].intVal div args[1].intVal) * args[1].intVal))
       return EvalResult(ok: false, error: "rem requires integers")
 
     of "min":
@@ -984,9 +979,16 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
       if args.len == 3 and args[0].kind == ckInt and args[1].kind == ckInt and args[2].kind == ckInt:
         var items: seq[CljVal] = @[]
         var i = args[0].intVal
-        while i < args[1].intVal:
-          items.add(cljInt(i))
-          i += args[2].intVal
+        let step = args[2].intVal
+        let endVal = args[1].intVal
+        if step > 0:
+          while i < endVal:
+            items.add(cljInt(i))
+            i += step
+        elif step < 0:
+          while i > endVal:
+            items.add(cljInt(i))
+            i += step
         return EvalResult(ok: true, value: cljList(items))
       return EvalResult(ok: false, error: "range requires integers")
 
@@ -1132,7 +1134,8 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
       let currentVal = atomRegistry[args[0].strVal]
       var callItems = @[fn, currentVal]
       if args.len > 2:
-        callItems.add(args[2..^1])
+        for extra in args[2..^1]:
+          callItems.add(extra)
       let callRes = evalList(callItems, env)
       if not callRes.ok: return callRes
       atomRegistry[args[0].strVal] = callRes.value
diff --git a/src/macros.nim b/src/macros.nim
index 2470cb2..6eaa44f 100644
--- a/src/macros.nim
+++ b/src/macros.nim
@@ -428,8 +428,7 @@ proc initMacros*() =
       if whileExpr != nil:
         let gs = cljSymbol(gensymName("dw_"))
         b = @[cljList(@[cljSymbol("loop"), cljVector(@[gs, cljBool(true)]),
-          cljList(@[cljSymbol("when"), whileExpr] & b & @[cljList(@[cljSymbol("recur"), gs])]),
-          cljList(@[cljSymbol("when"), cljBool(false), cljNil()])])]
+          cljList(@[cljSymbol("when"), whileExpr] & b & @[cljList(@[cljSymbol("recur"), gs])])])]
       return cljList(@[cljSymbol("do")] & b)
     
     # Build nested doseq for multiple pairs, innermost gets the body with modifiers
@@ -438,11 +437,10 @@ proc initMacros*() =
       inner = @[cljList(@[cljSymbol("let"), cljVector(letBinds)] & inner)]
     if whenExpr != nil:
       inner = @[cljList(@[cljSymbol("when"), whenExpr] & inner)]
-      if whileExpr != nil:
-        let gs = cljSymbol(gensymName("dw_"))
-        inner = @[cljList(@[cljSymbol("loop"), cljVector(@[gs, cljBool(true)]),
-          cljList(@[cljSymbol("when"), whileExpr] & inner & @[cljList(@[cljSymbol("recur"), gs])]),
-          cljList(@[cljSymbol("when"), cljBool(false), cljNil()])])]
+    if whileExpr != nil:
+      let gs = cljSymbol(gensymName("dw_"))
+      inner = @[cljList(@[cljSymbol("loop"), cljVector(@[gs, cljBool(true)]),
+        cljList(@[cljSymbol("when"), whileExpr] & inner & @[cljList(@[cljSymbol("recur"), gs])])])]
     
     proc makeLoop(name: CljVal, coll: CljVal, innerBody: seq[CljVal]): CljVal =
       if name.kind == ckVector:
@@ -606,5 +604,9 @@ proc initMacros*() =
     return cljList(@[cljSymbol("do")] & body)
   )
 
+var macrosInitialized = false
+
 proc initBuiltinMacros*() =
+  if macrosInitialized: return
   initMacros()
+  macrosInitialized = true
diff --git a/src/reader.nim b/src/reader.nim
index a4a8403..a28c74f 100644
--- a/src/reader.nim
+++ b/src/reader.nim
@@ -227,6 +227,20 @@ proc readAtom(s: string, i: var int): CljVal =
       except CatchableError:
         return cljSymbol(tok)
 
+  # Check for ratio literal like 1/5, -1/5, 3/4
+  let slashPos = numTok.find('/')
+  if slashPos > 0 and slashPos < numTok.len - 1:
+    let numerStr = numTok[0..<slashPos]
+    let denomStr = numTok[slashPos+1..^1]
+    try:
+      let numer = parseInt(numerStr)
+      let denom = parseInt(denomStr)
+      if denom != 0:
+        return cljList(@[cljSymbol("/"), cljInt(numer.int64), cljInt(denom.int64)])
+    except CatchableError:
+      discard
+    return cljSymbol(tok)
+
   # number
   var isFloat = false
   var isNumber = true
@@ -252,8 +266,8 @@ proc readAtom(s: string, i: var int): CljVal =
       if j + 1 < numTok.len and (numTok[j+1] == '-' or numTok[j+1] == '+'):
         discard  # skip exponent sign
     elif numTok[j] notin Digits:
-      if sawExp and (tok[j] == '-' or tok[j] == '+'):
-        if j > 0 and (tok[j-1] == 'e' or tok[j-1] == 'E'):
+      if sawExp and (numTok[j] == '-' or numTok[j] == '+'):
+        if j > 0 and (numTok[j-1] == 'e' or numTok[j-1] == 'E'):
           continue
       isNumber = false
       break
@@ -354,7 +368,7 @@ proc readMap(s: string, i: var int): CljVal =
   return cljMapFromPairs(pairs)
 
 proc readSet(s: string, i: var int): CljVal =
-  inc i  # skip '{' after # 
+  inc i  # skip '{' after #
   var items: seq[CljVal] = @[]
   while true:
     skipWhitespaceAndComments(s, i)
@@ -366,7 +380,7 @@ proc readSet(s: string, i: var int): CljVal =
     let form = readForm(s, i)
     if form != nil:
       items.add(form)
-  return cljList(@[cljSymbol("set"), cljVector(items)])
+  return cljSet(items)
 
 proc readDispatch(s: string, i: var int): CljVal =
   inc i  # skip '#'
diff --git a/src/repl.nim b/src/repl.nim
index ad76769..4da6e0e 100644
--- a/src/repl.nim
+++ b/src/repl.nim
@@ -528,8 +528,14 @@ proc handleClient(state: var ReplState, client: Socket) =
         client.send($(%*{ "status": "error", "error": { "type": "repl/unknown-op", "message": "Unknown op: " & op } }) & "\n")
     except EOFError:
       break
-    except:
-      client.send($(%*{ "status": "error", "error": { "type": "repl/protocol-error", "message": "Protocol error" } }) & "\n")
+    except CatchableError as e:
+      client.send($(%*{ "status": "error", "error": { "type": "repl/protocol-error", "message": e.msg } }) & "\n")
+      break
+    except ValueError as e:
+      client.send($(%*{ "status": "error", "error": { "type": "repl/parse-error", "message": e.msg } }) & "\n")
+      break
+    except OSError as e:
+      client.send($(%*{ "status": "error", "error": { "type": "repl/io-error", "message": e.msg } }) & "\n")
       break
   client.close()