separate Module and IO code

1 files changed, 71 insertions, 30 deletions

diff --git a/alv/module.moon b/alv/module.moon
index d530712..b10b0f9 100644
--- a/alv/module.moon
+++ b/alv/module.moon
@@ -1,41 +1,36 @@
 ----
 -- Per-file execution context.
 --
--- @classmod Module
+-- @module module
 import Registry from require 'alv.registry'
 import Error from require 'alv.error'
 import Scope from require 'alv.scope'
 import program from require 'alv.parsing'
 builtins = require 'alv.builtins'
 
-slurp = (file) ->
-  file = assert (io.open file, 'r'), Error 'io', "couldn't open '#{file}'"
-  with file\read '*all'
-    file\close!
-
-spit = (file, str) ->
-  file = io.open file, 'w'
-  file\write str
-  file\close!
-
+--- Base class for Modules.
+-- @type Module
 class Module
---- static functions
--- @section static
-
   --- create a new Module.
   -- @classmethod
-  new: (@file) =>
+  new: =>
     @registry = Registry!
 
---- members
--- @section members
+  --- check when the module source has last changed.
+  -- @function poll
+  -- @treturn number timestamp of last change
 
-  --- check whether file was changed.
-  -- @treturn bool whether the file was changed since the last call
-  poll: =>
-    { :mode, :modification } = (lfs.attributes @file) or {}
-    assert mode == 'file', Error 'io', "not a file: '#{@file}'"
-    modification
+  --- get the module basename.
+  -- @function name
+  -- @treturn string
+
+  --- get the module contents.
+  -- @function slurp
+  -- @treturn string
+
+  --- update the module contents.
+  -- @function spit
+  -- @tparam string str the updated contents
 
   --- start an evaluation cycle.
   --
@@ -43,7 +38,7 @@ class Module
   -- Otherwise, register the module with the `Copilot`. Updates `root`.
   eval: =>
     @registry\begin_eval!
-    @ast = Error.wrap "parsing '#{@file}'", -> program\match slurp @file
+    @ast = Error.wrap "parsing '#{@file}'", -> program\match @slurp!
     assert @ast, Error 'syntax', "failed to parse"
 
     scope = Scope builtins
@@ -56,17 +51,14 @@ class Module
   finish: =>
     tags_changed = @registry\end_eval!
     if tags_changed
-      spit @file, @ast\stringify!
+      @spit @ast\stringify!
 
   --- destroy this module.
   destroy: =>
     @registry\destroy!
 
-  --- get the module basename.
-  -- @treturn string
-  basename: => @file\match '([^/\\]+)$'
-
-  __tostring: => "<Module #{@basename!}>"
+  __tostring: => "<#{@@__name} #{@name!}>"
+  __inherited: (cls) => cls.__base.__tostring = @__tostring
 
   --- the last updated AST tree for this module.
   -- @tfield ?AST ast
@@ -74,6 +66,55 @@ class Module
   --- the runtime graph root of this module.
   -- @tfield ?RTNode root
 
+--- Module type for modules loaded from the filesystem.
+-- @type FSModule
+class FSModule extends Module
+  --- create a new FSModule.
+  -- @classmethod
+  -- @tparam string file filepath
+  new: (@file) =>
+    super!
+
+  slurp: =>
+    file = assert (io.open @file, 'r'), Error 'io', "couldn't open '#{@file}'"
+    with file\read '*all'
+      file\close!
+
+  spit: (str) =>
+    file = io.open @file, 'w'
+    file\write str
+    file\close!
+
+  poll: =>
+    { :mode, :modification } = (lfs.attributes @file) or {}
+    assert mode == 'file', Error 'io', "not a file: '#{@file}'"
+    modification
+
+  name: => @file\match '([^/\\]+)$'
+
+--- Module type for modules loaded from RAM.
+-- @type StringModule
+class StringModule extends Module
+  --- create a new StringModule.
+  -- @classmethod
+  -- @tparam string name_ module name
+  -- @tparam string source module source code
+  new: (@name_, @source) =>
+    super!
+    @updated = os.time!
+
+  slurp: => @source
+
+  spit: (str) =>
+    @source = str
+    @updated = os.time!
+
+  poll: => @updated
+
+  name: => @name_
+
 {
   :Module
+  :FSModule
+  :StringModule
 }