pureops with arbitrary pattern

3 files changed, 53 insertions, 28 deletions

diff --git a/alv/base/op.moon b/alv/base/op.moon
index da90288..a88bbe5 100644
--- a/alv/base/op.moon
+++ b/alv/base/op.moon
@@ -2,31 +2,16 @@
 -- Persistent expression Operator.
 --
 -- @classmod Op
-
-deepcopy = (val) ->
-  switch type val
-    when 'number', 'string', 'boolean', 'nil'
-      val
-    when 'table'
-      assert (not getmetatable {}), "state should only contain simple tables!"
-      {(deepcopy k), (deepcopy v) for k,v in pairs val}
-    else
-      error "state cannot contain values of type '#{type val}'"
+import deep_copy, deep_iter from require 'alv.util'
 
 class Op
 --- members
 -- @section members
 
-  do_yield = (table) ->
-    for k, v in pairs table
-      if v.__class
-        coroutine.yield v
-      else
-        do_yield v
   --- yield all `Input`s from the (potentially nested) `inputs` table
   --
   -- @treturn iterator iterator over `inputs`
-  all_inputs: => coroutine.wrap -> do_yield @inputs
+  all_inputs: => coroutine.wrap -> deep_iter @inputs
 
   --- create a mutable copy of this Op.
   --
@@ -36,7 +21,7 @@ class Op
   -- @treturn Op
   fork: =>
     out = if @out then @out\fork!
-    state = if @state then deepcopy @state
+    state = if @state then deep_copy @state
     @@ out, state
 
   --- internal state of this Op.
diff --git a/alv/base/pureop.moon b/alv/base/pureop.moon
index ea3b810..6a058f6 100644
--- a/alv/base/pureop.moon
+++ b/alv/base/pureop.moon
@@ -10,8 +10,9 @@
 -- @classmod PureOp
 import Op from require 'alv.base.op'
 import Input from require 'alv.base.input'
-import SigStream, EvtStream from require 'alv.result'
+import Type from require 'alv.type'
 import Error from require 'alv.error'
+import ancestor, deep_iter, deep_map from require 'alv.util'
 
 unpack or= table.unpack
 
@@ -24,32 +25,43 @@ class PureOp extends Op
   -- Must resolve to a simple sequence-table (depth 1).
   --
   -- @tfield match.Pattern pattern
-  @pattern: nil
 
-  --- the result type.
-  -- @tfield type.Type type
-  @type: nil
+  --- the result type or a method that returns it.
+  --
+  -- Can be either a method or just a fixed type.
+  --
+  -- @tparam table args as parsed by `pattern`
+  -- @treturn type.Type
 
   --- set up inputs for a range of things.
   setup: (inputs) =>
     args = @@pattern\match inputs
 
     local trigger
-    for arg in *args
+    for arg in coroutine.wrap -> deep_iter args
       if arg.result.metatype == '!'
         assert not trigger, Error 'argument', "pure op can take at most one !-stream."
         trigger = arg
 
+    typ = if (type @type) == 'table' then @type else @type args
+    assert (ancestor typ.__class) == Type, "not a type: #{typ}"
+
     if trigger
-      super for a in *args
+      super deep_map args, (a) ->
         if a == trigger
           Input.hot trigger
         else
           Input.cold a
-      @out = EvtStream @@type
+      -- super for a in *args
+      --   if a == trigger
+      --     Input.hot trigger
+      --   else
+      --     Input.cold a
+      @out = typ\mk_evt!
     else
-      super [Input.hot a for a in *args]
-      @out or= SigStream @@type
+      -- super [Input.hot a for a in *args]
+      super deep_map args, (a) -> Input.hot a
+      @out or= typ\mk_sig!
 
 {
   :PureOp
diff --git a/alv/util.moon b/alv/util.moon
index 316233b..e175600 100644
--- a/alv/util.moon
+++ b/alv/util.moon
@@ -31,7 +31,35 @@ ancestor = (klass) ->
     klass = klass.__parent
   klass
 
+--- check whether a table is a 'plain' table
+is_plain_table = (val) -> (type val) == 'table' and not val.__class
+
+--- recursively copy a value
+deep_copy = (val) ->
+  if is_plain_table val
+    {(deep_copy k), (deep_copy v) for k,v in pairs val}
+  else
+    val
+
+--- map leaf values in a table
+deep_map = (val, fn) ->
+  if is_plain_table val
+    {k, (deep_map v, fn) for k,v in pairs val}
+  else
+    fn val
+
+--- yield all leaf values in a table
+deep_iter = (table) ->
+  for k, v in pairs table
+    if is_plain_table v
+      deep_iter v
+    else
+      coroutine.yield v
+
 {
   :opairs
   :ancestor
+  :deep_copy
+  :deep_map
+  :deep_iter
 }