Phase 9: Agents (send/await/deref) + core.async channels (chan, >!, <!, close!, go). All phases complete.

src/eval.nim

@@ -1,8 +1,19 @@
 # Tree-walking interpreter for fast REPL evaluation
 # Handles common cases without spawning nim c
-import strutils, sequtils, tables, algorithm, times
+import strutils, sequtils, tables, algorithm, times, deques
 import types, reader
 
+var agentRegistry* = initTable[string, CljVal]()
+var agentCounter*: int64 = 0
+
+type
+  Channel* = ref object
+    buf: Deque[CljVal]
+    capacity: int  # 0 = unbuffered
+
+var channelRegistry* = initTable[string, Channel]()
+var channelCounter*: int64 = 0
+
 type
   EvalError* = object of CatchableError
 
@@ -1006,12 +1017,86 @@ proc evalList(items: seq[CljVal], env: Env): EvalResult =
 
     of "deref":
       numArgs(1)
+      if args[0].kind == ckString and agentRegistry.hasKey(args[0].strVal):
+        return EvalResult(ok: true, value: agentRegistry[args[0].strVal])
       return EvalResult(ok: true, value: args[0])
 
     of "atom":
       numArgs(1)
       return EvalResult(ok: true, value: args[0])
 
+    of "agent":
+      numArgs(1)
+      agentCounter += 1
+      let id = "agent_" & $agentCounter
+      agentRegistry[id] = args[0]
+      return EvalResult(ok: true, value: cljString(id))
+
+    of "send":
+      atLeast(2)
+      let agentId = args[0]
+      if agentId.kind != ckString or not agentRegistry.hasKey(agentId.strVal):
+        return EvalResult(ok: false, error: "send requires an agent")
+      let fn = args[1]
+      let fnArgs = if args.len > 2: args[2..^1] else: @[]
+      let currentVal = agentRegistry[agentId.strVal]
+      var callItems = @[fn, currentVal]
+      callItems.add(fnArgs)
+      let callRes = evalList(callItems, env)
+      if not callRes.ok: return callRes
+      agentRegistry[agentId.strVal] = callRes.value
+      return EvalResult(ok: true, value: callRes.value)
+
+    of "await":
+      numArgs(1)
+      return EvalResult(ok: true, value: cljNil())
+
+    of "shutdown-agents":
+      return EvalResult(ok: true, value: cljNil())
+
+    of "chan":
+      channelCounter += 1
+      let id = "chan_" & $channelCounter
+      let cap = if args.len > 0 and args[0].kind == ckInt: args[0].intVal.int else: 0
+      let ch = Channel(buf: initDeque[CljVal](), capacity: cap)
+      channelRegistry[id] = ch
+      return EvalResult(ok: true, value: cljString(id))
+
+    of "put!", ">!":
+      numArgs(2)
+      if args[0].kind != ckString or not channelRegistry.hasKey(args[0].strVal):
+        return EvalResult(ok: false, error: "put!/<! requires a channel")
+      let ch = channelRegistry[args[0].strVal]
+      if ch.capacity > 0 and ch.buf.len >= ch.capacity:
+        return EvalResult(ok: false, error: "Channel buffer full")
+      ch.buf.addLast(args[1])
+      return EvalResult(ok: true, value: cljBool(true))
+
+    of "take!", "<!":
+      numArgs(1)
+      if args[0].kind != ckString or not channelRegistry.hasKey(args[0].strVal):
+        return EvalResult(ok: false, error: "take!/<! requires a channel")
+      let ch = channelRegistry[args[0].strVal]
+      if ch.buf.len == 0:
+        return EvalResult(ok: true, value: cljNil())
+      return EvalResult(ok: true, value: ch.buf.popFirst())
+
+    of "close!":
+      numArgs(1)
+      if args[0].kind != ckString or not channelRegistry.hasKey(args[0].strVal):
+        return EvalResult(ok: false, error: "close! requires a channel")
+      channelRegistry.del(args[0].strVal)
+      return EvalResult(ok: true, value: cljNil())
+
+    of "go":
+      # In synchronous interpreter, go just evaluates the body
+      var lastVal: CljVal = cljNil()
+      for i in 1..<items.len:
+        let res = evalAst(items[i], env)
+        if not res.ok: return res
+        lastVal = res.value
+      return EvalResult(ok: true, value: lastVal)
+
     else:
       return EvalResult(ok: false, error: "Unknown function: " & name & " (use compile mode for full runtime)")