Fix and clean up Nim implementation

12 files changed, 66 insertions, 62 deletions

diff --git a/nim/Makefile b/nim/Makefile
index 4b8707d..e8c450e 100644
--- a/nim/Makefile
+++ b/nim/Makefile
@@ -18,7 +18,7 @@ all: $(BINS) mal
 mal: $(word $(words $(BINS)),$(BINS))
 	cp $< $@
 
-$(BINS):
+$(BINS): %: %.nim
 	nim -d:release c $@
 
 clean:
diff --git a/nim/core.nim b/nim/core.nim
index 5fc9e63..e5ca517 100644
--- a/nim/core.nim
+++ b/nim/core.nim
@@ -57,21 +57,22 @@ proc throw(xs: varargs[MalType]): MalType =
 
 proc assoc(xs: varargs[MalType]): MalType =
   result = hash_map()
-  result.hash_map[] = xs[0].hash_map[]
+  result.hash_map = xs[0].hash_map
   for i in countup(1, xs.high, 2):
     result.hash_map[xs[i].str] = xs[i+1]
 
 proc dissoc(xs: varargs[MalType]): MalType =
   result = hash_map()
-  result.hash_map[] = xs[0].hash_map[]
+  result.hash_map = xs[0].hash_map
   for i in 1 .. xs.high:
     if result.hash_map.hasKey(xs[i].str): result.hash_map.del(xs[i].str)
 
 proc get(xs: varargs[MalType]): MalType =
   if xs[0].kind == HashMap:
-    xs[0].hash_map[xs[1].str]
-  else:
-    nilObj
+    result = xs[0].hash_map[xs[1].str]
+    if not result.isNil: return
+
+  result = nilObj
 
 proc contains_q(xs: varargs[MalType]): MalType =
   boolObj xs[0].hash_map.hasKey(xs[1].str)
@@ -113,27 +114,27 @@ proc map(xs: varargs[MalType]): MalType =
     result.list.add xs[0].getFun()(xs[1].list[i])
 
 proc with_meta(xs: varargs[MalType]): MalType =
-  result = xs[0]
-  new result.meta
-  result.meta[] = xs[1]
+  new result
+  result[] = xs[0][]
+  result.meta = xs[1]
 
 proc meta(xs: varargs[MalType]): MalType =
-  if xs[0].meta != nil: xs[0].meta[]
+  if not xs[0].meta.isNil: xs[0].meta
   else: nilObj
 
 proc deref(xs: varargs[MalType]): MalType =
-  xs[0].val[]
+  xs[0].val
 
 proc reset_bang(xs: varargs[MalType]): MalType =
-  xs[0].val[] = xs[1]
-  result = xs[0].val[]
+  xs[0].val = xs[1]
+  result = xs[0].val
 
 proc swap_bang(xs: varargs[MalType]): MalType =
-  var args = @[xs[0].val[]]
+  var args = @[xs[0].val]
   for i in 2 .. xs.high:
     args.add xs[i]
-  xs[0].val[] = xs[1].getFun()(args)
-  result = xs[0].val[]
+  xs[0].val = xs[1].getFun()(args)
+  result = xs[0].val
 
 proc time_ms(xs: varargs[MalType]): MalType =
   number int(epochTime() * 1000)
diff --git a/nim/nim.cfg b/nim/nim.cfg
index 55df3f9..dbf197a 100644
--- a/nim/nim.cfg
+++ b/nim/nim.cfg
@@ -1,2 +1,2 @@
-d: pcreDynlib
 deadCodeElim: off
+gc: markandsweep
diff --git a/nim/printer.nim b/nim/printer.nim
index 95eb840..912b8a9 100644
--- a/nim/printer.nim
+++ b/nim/printer.nim
@@ -13,7 +13,7 @@ proc pr_str*(m: MalType, pr = true): string =
   of False:   result = "false"
   of Fun:     result = "#<function>"
   of MalFun:  result = "#<malfun>"
-  of Atom:    result = "(atom " & m.val[].pr_str & ")"
+  of Atom:    result = "(atom " & m.val.pr_str & ")"
   of Symbol:  result = m.str
   of String:  result = m.str.str_handle(pr)
   of Number:  result = $m.number
diff --git a/nim/reader.nim b/nim/reader.nim
index 856a6a6..10fce10 100644
--- a/nim/reader.nim
+++ b/nim/reader.nim
@@ -1,6 +1,6 @@
 import nre, optional_t, strutils, types
 
-var
+let
   tokenRE = re"""[\s,]*(~@|[\[\]{}()'`~^@]|"(?:\\.|[^\\"])*"|;.*|[^\s\[\]{}('"`,;)]*)"""
   intRE   = re"-?[0-9]+$"
 
diff --git a/nim/step5_tco.nim b/nim/step5_tco.nim
index a03dbd1..bbbb160 100644
--- a/nim/step5_tco.nim
+++ b/nim/step5_tco.nim
@@ -20,20 +20,20 @@ proc eval_ast(ast: MalType, env: var Env): MalType =
     result = ast
 
 proc eval(ast: MalType, env: var Env): MalType =
+  var ast = ast
+
   template defaultApply =
     let el = ast.eval_ast(env)
     let f = el.list[0]
     case f.kind
     of MalFun:
       ast = f.malfun.ast
-      env = initEnv(env, f.malfun.params, list(el.list[1 .. -1]))
+      env = initEnv(f.malfun.env, f.malfun.params, list(el.list[1 .. -1]))
     else:
       return f.fun(el.list[1 .. -1])
 
-  var ast = ast
   while true:
-    if ast.kind != List:
-      return ast.eval_ast(env)
+    if ast.kind != List: return ast.eval_ast(env)
 
     let a0 = ast.list[0]
     case a0.kind
@@ -62,7 +62,7 @@ proc eval(ast: MalType, env: var Env): MalType =
       of "do":
         let last = ast.list.high
         let el = (list ast.list[1 .. <last]).eval_ast(env)
-        ast = ast.list[last].eval(env)
+        ast = ast.list[last]
         # Continue loop (TCO)
 
       of "if":
@@ -84,7 +84,7 @@ proc eval(ast: MalType, env: var Env): MalType =
         let fn = proc(a: varargs[MalType]): MalType =
           var newEnv = initEnv(env2, a1, list(a))
           a2.eval(newEnv)
-        return malfun(fn, a2, a1, env2)
+        return malfun(fn, a2, a1, env)
 
       else:
         defaultApply()
diff --git a/nim/step6_file.nim b/nim/step6_file.nim
index 6f0e02a..a0a569e 100644
--- a/nim/step6_file.nim
+++ b/nim/step6_file.nim
@@ -20,20 +20,20 @@ proc eval_ast(ast: MalType, env: var Env): MalType =
     result = ast
 
 proc eval(ast: MalType, env: var Env): MalType =
+  var ast = ast
+
   template defaultApply =
     let el = ast.eval_ast(env)
     let f = el.list[0]
     case f.kind
     of MalFun:
       ast = f.malfun.ast
-      env = initEnv(env, f.malfun.params, list(el.list[1 .. -1]))
+      env = initEnv(f.malfun.env, f.malfun.params, list(el.list[1 .. -1]))
     else:
       return f.fun(el.list[1 .. -1])
 
-  var ast = ast
   while true:
-    if ast.kind != List:
-      return ast.eval_ast(env)
+    if ast.kind != List: return ast.eval_ast(env)
 
     let a0 = ast.list[0]
     case a0.kind
@@ -62,7 +62,7 @@ proc eval(ast: MalType, env: var Env): MalType =
       of "do":
         let last = ast.list.high
         let el = (list ast.list[1 .. <last]).eval_ast(env)
-        ast = ast.list[last].eval(env)
+        ast = ast.list[last]
         # Continue loop (TCO)
 
       of "if":
@@ -84,7 +84,7 @@ proc eval(ast: MalType, env: var Env): MalType =
         let fn = proc(a: varargs[MalType]): MalType =
           var newEnv = initEnv(env2, a1, list(a))
           a2.eval(newEnv)
-        return malfun(fn, a2, a1, env2)
+        return malfun(fn, a2, a1, env)
 
       else:
         defaultApply()
diff --git a/nim/step7_quote.nim b/nim/step7_quote.nim
index 58fc3b6..848913d 100644
--- a/nim/step7_quote.nim
+++ b/nim/step7_quote.nim
@@ -34,20 +34,20 @@ proc eval_ast(ast: MalType, env: var Env): MalType =
     result = ast
 
 proc eval(ast: MalType, env: var Env): MalType =
+  var ast = ast
+
   template defaultApply =
     let el = ast.eval_ast(env)
     let f = el.list[0]
     case f.kind
     of MalFun:
       ast = f.malfun.ast
-      env = initEnv(env, f.malfun.params, list(el.list[1 .. -1]))
+      env = initEnv(f.malfun.env, f.malfun.params, list(el.list[1 .. -1]))
     else:
       return f.fun(el.list[1 .. -1])
 
-  var ast = ast
   while true:
-    if ast.kind != List:
-      return ast.eval_ast(env)
+    if ast.kind != List: return ast.eval_ast(env)
 
     let a0 = ast.list[0]
     case a0.kind
@@ -83,7 +83,7 @@ proc eval(ast: MalType, env: var Env): MalType =
       of "do":
         let last = ast.list.high
         let el = (list ast.list[1 .. <last]).eval_ast(env)
-        ast = ast.list[last].eval(env)
+        ast = ast.list[last]
         # Continue loop (TCO)
 
       of "if":
@@ -105,7 +105,7 @@ proc eval(ast: MalType, env: var Env): MalType =
         let fn = proc(a: varargs[MalType]): MalType =
           var newEnv = initEnv(env2, a1, list(a))
           a2.eval(newEnv)
-        return malfun(fn, a2, a1, env2)
+        return malfun(fn, a2, a1, env)
 
       else:
         defaultApply()
diff --git a/nim/step8_macros.nim b/nim/step8_macros.nim
index 43c1cb4..96981a7 100644
--- a/nim/step8_macros.nim
+++ b/nim/step8_macros.nim
@@ -26,7 +26,7 @@ proc macroexpand(ast: MalType, env: Env): MalType =
     let mac = env.get(result.list[0].str)
     result = mac.malfun.fn(result.list[1 .. -1]).macroexpand(env)
 
-proc eval(ast: MalType, env: var Env): MalType
+proc eval(ast: MalType, env: Env): MalType
 
 proc eval_ast(ast: MalType, env: var Env): MalType =
   case ast.kind
@@ -43,18 +43,20 @@ proc eval_ast(ast: MalType, env: var Env): MalType =
   else:
     result = ast
 
-proc eval(ast: MalType, env: var Env): MalType =
+proc eval(ast: MalType, env: Env): MalType =
+  var ast = ast
+  var env = env
+
   template defaultApply =
     let el = ast.eval_ast(env)
     let f = el.list[0]
     case f.kind
     of MalFun:
       ast = f.malfun.ast
-      env = initEnv(env, f.malfun.params, list(el.list[1 .. -1]))
+      env = initEnv(f.malfun.env, f.malfun.params, list(el.list[1 .. -1]))
     else:
       return f.fun(el.list[1 .. -1])
 
-  var ast = ast
   while true:
     if ast.kind != List: return ast.eval_ast(env)
 
@@ -104,7 +106,7 @@ proc eval(ast: MalType, env: var Env): MalType =
       of "do":
         let last = ast.list.high
         let el = (list ast.list[1 .. <last]).eval_ast(env)
-        ast = ast.list[last].eval(env)
+        ast = ast.list[last]
         # Continue loop (TCO)
 
       of "if":
@@ -126,7 +128,7 @@ proc eval(ast: MalType, env: var Env): MalType =
         let fn = proc(a: varargs[MalType]): MalType =
           var newEnv = initEnv(env2, a1, list(a))
           a2.eval(newEnv)
-        return malfun(fn, a2, a1, env2)
+        return malfun(fn, a2, a1, env)
 
       else:
         defaultApply()
diff --git a/nim/step9_try.nim b/nim/step9_try.nim
index 688817d..6d77ac7 100644
--- a/nim/step9_try.nim
+++ b/nim/step9_try.nim
@@ -125,7 +125,7 @@ proc eval(ast: MalType, env: Env): MalType =
       of "do":
         let last = ast.list.high
         let el = (list ast.list[1 .. <last]).eval_ast(env)
-        ast = ast.list[last].eval(env)
+        ast = ast.list[last]
         # Continue loop (TCO)
 
       of "if":
diff --git a/nim/stepA_mal.nim b/nim/stepA_mal.nim
index 48dd9dd..b138bd9 100644
--- a/nim/stepA_mal.nim
+++ b/nim/stepA_mal.nim
@@ -175,11 +175,12 @@ rep "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (
 rep "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
 rep "(def! *host-language* \"nim\")"
 
-rep "(println (str \"Mal [\" *host-language* \"]\"))"
 if paramCount() >= 1:
   rep "(load-file \"" & paramStr(1) & "\")"
   quit()
 
+rep "(println (str \"Mal [\" *host-language* \"]\"))"
+
 while true:
   try:
     let line = readLineFromStdin("user> ")
diff --git a/nim/types.nim b/nim/types.nim
index b5e1bec..56983ff 100644
--- a/nim/types.nim
+++ b/nim/types.nim
@@ -13,28 +13,28 @@ type
     env*:      Env
     is_macro*: bool
 
-  MalType* = object
+  MalType* = ref object
     case kind*: MalTypeKind
     of Nil, True, False: nil
     of Number:           number*:   int
     of String, Symbol:   str*:      string
     of List, Vector:     list*:     seq[MalType]
-    of HashMap:          hash_map*: TableRef[string, MalType]
+    of HashMap:          hash_map*: Table[string, MalType]
     of Fun:
                          fun*:      FunType
                          is_macro*: bool
     of MalFun:           malfun*:   MalFunType
-    of Atom:             val*:      ref MalType
+    of Atom:             val*:      MalType
 
-    meta*: ref MalType
+    meta*: MalType
 
   Env* = ref object
     data*: Table[string, MalType]
     outer*: Env
 
-const nilObj* = MalType(kind: Nil)
-const trueObj* = MalType(kind: True)
-const falseObj* = MalType(kind: False)
+let nilObj* = MalType(kind: Nil)
+let trueObj* = MalType(kind: True)
+let falseObj* = MalType(kind: False)
 
 proc number*(x: int): MalType = MalType(kind: Number, number: x)
 
@@ -46,19 +46,18 @@ proc keyword*(x: string): MalType = MalType(kind: String, str: "\xff" & x)
 
 proc atom*(x: MalType): MalType =
   result = MalType(kind: Atom)
-  new result.val
-  result.val[] = x
+  result.val = x
 
 proc list*(xs: varargs[MalType]): MalType {.procvar.} =
-  result = MalType(kind: List, list: @[])
-  for x in xs: result.list.add x
+  result = MalType(kind: List, list: newSeq[MalType](xs.len))
+  for i, x in xs: result.list[i] = x
 
 proc vector*(xs: varargs[MalType]): MalType {.procvar.} =
-  result = MalType(kind: Vector, list: @[])
-  for x in xs: result.list.add x
+  result = MalType(kind: Vector, list: newSeq[MalType](xs.len))
+  for i, x in xs: result.list[i] = x
 
 proc hash_map*(xs: varargs[MalType]): MalType {.procvar.} =
-  result = MalType(kind: HashMap, hash_map: newTable[string, MalType]())
+  result = MalType(kind: HashMap, hash_map: initTable[string, MalType]())
   for i in countup(0, xs.high, 2):
     let s = case xs[i].kind
     of String: xs[i].str
@@ -66,13 +65,14 @@ proc hash_map*(xs: varargs[MalType]): MalType {.procvar.} =
     result.hash_map[s] = xs[i+1]
 
 proc macro_q*(x: MalType): bool =
-  if x.kind == Fun: x.is_macro
-  else: x.malfun.is_macro
+  if x.kind == Fun: result = x.is_macro
+  elif x.kind == MalFun: result = x.malfun.is_macro
+  else: raise newException(ValueError, "no function")
 
 proc getFun*(x: MalType): FunType =
   if x.kind == Fun: result = x.fun
   elif x.kind == MalFun: result = x.malfun.fn
-  else: echo x.kind
+  else: raise newException(ValueError, "no function")
 
 proc fun*(x: proc(xs: varargs[MalType]): MalType, is_macro = false): MalType =
   MalType(kind: Fun, fun: x, is_macro: is_macro)