Major changes to how versioning and parsing work. This should be a

better path going forward to handling upgrades. Old syntax files will
stick around for compatibility purposes. Old syntax can be parsed into
valid syntax trees via the old syntax (.peg) files, and then old syntax
trees should be valid and can be upgraded via the normal code path. This
change has lots of improvements to Nomsu codegen too.

1 files changed, 13 insertions, 5 deletions

diff --git a/nomsu_tree.moon b/nomsu_tree.moon
index e387f37..923bd72 100644
--- a/nomsu_tree.moon
+++ b/nomsu_tree.moon
@@ -10,7 +10,7 @@ AST.is_syntax_tree = (n, t=nil)->
     type(n) == 'table' and getmetatable(n) and AST[n.type] == getmetatable(n) and (t == nil or n.type == t)
 
 types = {"Number", "Var", "Block", "EscapedNomsu", "Text", "List", "Dict", "DictEntry",
-    "IndexChain", "Action", "File"}
+    "IndexChain", "Action", "FileChunks"}
 for name in *types
     cls = {}
     with cls
@@ -21,10 +21,18 @@ for name in *types
         .is_instance = (x)=> getmetatable(x) == @
         .__tostring = => "#{@type}(#{repr tostring(@source)}, #{concat([repr(v) for v in *@], ', ')})"
         .map = (fn)=>
-            if replacement = fn(@) then return replacement
-            replacements = [AST.is_syntax_tree(v) and v\map(fn) or nil for v in *@]
-            return @ unless next(replacements)
-            return (@__class)(@source, unpack([replacements[i] or v for i,v in ipairs(@)]))
+            replacement = fn(@)
+            if replacement != nil then return replacement or nil
+            replacements = {}
+            changes = false
+            for i,v in ipairs(@)
+                replacement = if AST.is_syntax_tree(v)
+                    v\map(fn)
+                else v
+                changes or= replacement != v
+                replacements[#replacements+1] = replacement
+            return @ unless changes
+            return (@__class)(@source, unpack(replacements))
 
     AST[name] = setmetatable cls,
         __tostring: => @name