more flexible AST\walk

4 files changed, 55 insertions, 43 deletions

diff --git a/ast.moon b/ast.moon
index b6be5f5..d7735fd 100644
--- a/ast.moon
+++ b/ast.moon
@@ -8,10 +8,12 @@ unescape = (str) ->
   str
 
 class Atom
+  type: 'Atom'
+
   new: (@raw, @style='', value) =>
     @value = Const value
 
-  _walk_sexpr: =>
+  _walk: => coroutine.yield @type, @
 
   stringify: =>
     switch @style
@@ -32,6 +34,8 @@ class Atom
   __tostring: => @stringify!
 
 class Xpr
+  type: 'Xpr'
+  
   new: (parts, @style='(', tag) =>
     @white = {}
     @white[0] = parts[1]
@@ -43,19 +47,21 @@ class Xpr
     if tag
       @tag = tag.value\getc!
 
-  _walk_sexpr: =>
-    -- depth first
+  _walk: (dir, yield_self=true) =>
+    coroutine.yield @type, @ if yield_self and dir == 'outin'
+
     for frag in *@
-      frag\_walk_sexpr!
+      frag\_walk dir
+
+    coroutine.yield @type, @ if yield_self and dir == 'inout'
 
-    if @style == '('
-      coroutine.yield @
 
   head: => @[1].value
   tail: => unpack [p.value for p in *@[2,]]
 
-  walk_sexpr: =>
-    coroutine.wrap -> @_walk_sexpr!
+  walk: (dir, yield_self=true) =>
+    assert dir == 'inout' or dir == 'outin', "dir has to be either inout or outin"
+    coroutine.wrap -> @_walk dir, yield_self
 
   stringify: =>
     buf = ''
diff --git a/registry.moon b/registry.moon
index a7b4c9d..394267c 100644
--- a/registry.moon
+++ b/registry.moon
@@ -25,7 +25,9 @@ class Registry
     seen = {}
     to_tag = {}
 
-    for sexpr in @root\walk_sexpr!
+    for typ, sexpr in @root\walk 'inout', false
+      continue unless typ == 'Xpr'
+
       if not sexpr.tag
         @spawn_expr sexpr
         table.insert to_tag, sexpr
@@ -72,7 +74,8 @@ class Registry
 
   update: (dt) =>
     -- for tag, sexpr in pairs @map
-    for sexpr in @root\walk_sexpr!
+    for typ, sexpr in @root\walk 'inout', false
+      continue unless typ == 'Xpr'
       continue unless sexpr.value
 
       ok, err = pcall sexpr.value.update, sexpr.value, dt
diff --git a/spec/ast_spec.moon b/spec/ast_spec.moon
index cfb64cf..80fbb56 100644
--- a/spec/ast_spec.moon
+++ b/spec/ast_spec.moon
@@ -1,15 +1,36 @@
 import Atom, Xpr from require 'ast'
 
-describe 'Xpr', ->
-  it 'can be walked', ->
-    aa = Xpr { '', (Atom '1', '', 1), '' }
-    ab = Xpr { '', (Atom '2', '', 2), '' }
-    ac = Xpr { '', (Atom '3', '', 3), '' }
-    b = Xpr { '', aa, ' ', ab, '' }
-
-    root = Xpr { '', ac, ' ', b, '' }, 'naked'
-
-    iter = root\walk_sexpr!
-    for res in *{ ac, aa, ab, b }
-      assert.is.equal res, iter!
-    assert.is.nil iter!
+describe 'AST', ->
+  describe 'can be walked', ->
+    a1 = Atom '1', '', 1
+    a2 = Atom '2', '', 2
+    a3 = Atom '3', '', 3
+    x1 = Xpr { '', a1, '' }
+    x21 = Xpr { '', a2, '' }
+    x22 = Xpr { '', a3, '' }
+    x2 = Xpr { '', x21, ' ', x22, '' }
+
+    root = Xpr { '', x1, ' ', x2, '' }, 'naked'
+
+    assert_yields = (expected_order, iter) ->
+      for val in *expected_order
+        got_typ, got_val = iter!
+        assert.is.equal val.type, got_typ
+        assert.is.equal val, got_val
+      assert.is.nil iter!
+
+    it 'inside-out', ->
+      assert_yields { a1, x1, a2, x21, a3, x22, x2, root }, root\walk 'inout'
+
+    it 'inside-out, skipping the root', ->
+      assert_yields { a1, x1, a2, x21, a3, x22, x2 }, root\walk 'inout', false
+
+    it 'outside-in', ->
+      assert_yields { root, x1, a1, x2, x21, a2, x22, a3 }, root\walk 'outin'
+
+    it 'outside-in, skipping the root', ->
+      assert_yields { x1, a1, x2, x21, a2, x22, a3 }, root\walk 'outin', false
+
+    it 'errors when direction is wrong or absent', ->
+      assert.has.errors -> root\walk!
+      assert.has.errors -> root\walk 'backandforth'
diff --git a/test.alv b/test.alv
index 81b1b65..370ae41 100644
--- a/test.alv
+++ b/test.alv
@@ -1,20 +1,2 @@
-#(this is a comment)
-([2]debug/out 'a' ([6]math/mix 0.5 1 ([5]time/lfo 1)))
-
-
-([16]util/pick 2 3)
-
-([14]math/mix 0 2 0.5)
-
-([13]debug/out 'b' ([12]math/mix 0 ([11]util/pick ([10]time/tick 4)
-  0.25
-  0.5
-  0.75
-  1) ([3]time/lfo 1 tri)))
-
-([9]debug/out 'name' ([8]util/pick ([7]time/tick 1)
-  0.1
-  0.6
-  0.3
-  0.9))
-
+([2]osc/out '127.0.0.1' 9000 '/param/radius/set' ([1]time/lfo 1))
+([4]osc/out '127.0.0.1' 9000 '/param/offset/set' ([3]time/lfo 1.0 'saw'))