continue support in foreach loop

Author: leafo

moonscript/compile.lua

@@ -134,6 +134,17 @@ Block = (function()
     get = function(self, name)
       return self._state[name]
     end,
+    listen = function(self, name, fn)
+      self._listeners[name] = fn
+    end,
+    send = function(self, name, ...)
+      do
+        local fn = self._listeners[name]
+        if fn then
+          return fn(self, ...)
+        end
+      end
+    end,
     declare = function(self, names)
       local undeclared = (function()
         local _accum_0 = { }
@@ -173,11 +184,15 @@ Block = (function()
     whitelist_names = function(self, names)
       self._name_whitelist = Set(names)
     end,
-    put_name = function(self, name)
+    put_name = function(self, name, ...)
+      value = ...
+      if select("#", ...) == 0 then
+        value = true
+      end
       if util.moon.type(name) == NameProxy then
         name = name:get_name(self)
       end
-      self._names[name] = true
+      self._names[name] = value
     end,
     has_name = function(self, name, skip_exports)
       if not skip_exports then
@@ -415,6 +430,14 @@ Block = (function()
         self:stm(stm)
       end
       return nil
+    end,
+    splice = function(self, fn)
+      local lines = {
+        "lines",
+        self._lines
+      }
+      self._lines = { }
+      return self:stms(fn(lines))
     end
   }
   _base_0.__index = _base_0
@@ -429,6 +452,7 @@ Block = (function()
       self._posmap = { }
       self._names = { }
       self._state = { }
+      self._listeners = { }
       do
         local _with_0 = transform
         self.transform = {
@@ -439,9 +463,12 @@ Block = (function()
       if self.parent then
         self.root = self.parent.root
         self.indent = self.parent.indent + 1
-        return setmetatable(self._state, {
+        setmetatable(self._state, {
           __index = self.parent._state
         })
+        return setmetatable(self._listeners, {
+          __index = self.parent._listeners
+        })
       else
         self.indent = 0
       end

moonscript/compile.moon

@@ -70,6 +70,7 @@ class Block
     @_posmap = {}
     @_names = {}
     @_state = {}
+    @_listeners = {}
 
     with transform
       @transform = {
@@ -81,6 +82,7 @@ class Block
       @root = @parent.root
       @indent = @parent.indent + 1
       setmetatable @_state, { __index: @parent._state }
+      setmetatable @_listeners, { __index: @parent._listeners }
     else
       @indent = 0
 
@@ -98,6 +100,13 @@ class Block
   get: (name) =>
     @_state[name]
 
+  listen: (name, fn) =>
+    @_listeners[name] = fn
+
+  send: (name, ...) =>
+    if fn = @_listeners[name]
+      fn self, ...
+
   declare: (names) =>
     undeclared = for name in *names
       is_local = false
@@ -116,9 +125,12 @@ class Block
   whitelist_names: (names) =>
     @_name_whitelist = Set names
 
-  put_name: (name) =>
+  put_name: (name, ...) =>
+    value = ...
+    value = true if select("#", ...) == 0
+
     name = name\get_name self if util.moon.type(name) == NameProxy
-    @_names[name] = true
+    @_names[name] = value
 
   has_name: (name, skip_exports) =>
     if not skip_exports
@@ -282,6 +294,11 @@ class Block
     @stm stm for stm in *stms
     nil
 
+  splice: (fn) =>
+    lines = {"lines", @_lines}
+    @_lines = {}
+    @stms fn lines
+
 class RootBlock extends Block
   new: (...) =>
     @root = self

moonscript/compile/statement.lua

@@ -2,6 +2,8 @@ module("moonscript.compile", package.seeall)
 local util = require("moonscript.util")
 require("moonscript.compile.format")
 local dump = require("moonscript.dump")
+local transform = require("moonscript.transform")
+local NameProxy = transform.NameProxy
 local reversed = util.reversed
 local ntype
 do
@@ -11,8 +13,14 @@ end
 local concat, insert = table.concat, table.insert
 line_compile = {
   raw = function(self, node)
-    local _, text = unpack(node)
-    return self:add(text)
+    return self:add(node[2])
+  end,
+  lines = function(self, node)
+    local _list_0 = node[2]
+    for _index_0 = 1, #_list_0 do
+      local line = _list_0[_index_0]
+      self:add(line)
+    end
   end,
   declare = function(self, node)
     local names = node[2]
@@ -142,6 +150,14 @@ line_compile = {
     end
     return root
   end,
+  ["repeat"] = function(self, node)
+    local cond, block = unpack(node, 2)
+    do
+      local _with_0 = self:block("repeat", self:line("until ", self:value(cond)))
+      _with_0:stms(block)
+      return _with_0
+    end
+  end,
   ["while"] = function(self, node)
     local _, cond, block = unpack(node)
     local out
@@ -215,12 +231,66 @@ line_compile = {
       _with_0:append(" do")
       loop = _with_0
     end
+    local continue_name = nil
+    local out
     do
       local _with_0 = self:block(loop)
+      _with_0:listen("continue", function()
+        if not (continue_name) then
+          continue_name = NameProxy("continue")
+          _with_0:put_name(continue_name)
+        end
+        return continue_name
+      end)
       _with_0:declare(names)
       _with_0:stms(block)
-      return _with_0
+      out = _with_0
+    end
+    if continue_name then
+      out:put_name(continue_name, nil)
+      out:splice(function(lines)
+        return {
+          {
+            "assign",
+            {
+              continue_name
+            },
+            {
+              "false"
+            }
+          },
+          {
+            "repeat",
+            "true",
+            {
+              lines,
+              {
+                "assign",
+                {
+                  continue_name
+                },
+                {
+                  "true"
+                }
+              }
+            }
+          },
+          {
+            "if",
+            {
+              "not",
+              continue_name
+            },
+            {
+              {
+                "break"
+              }
+            }
+          }
+        }
+      end)
     end
+    return out
   end,
   export = function(self, node)
     local _, names = unpack(node)

moonscript/compile/statement.moon

@@ -4,17 +4,21 @@ util = require "moonscript.util"
 
 require "moonscript.compile.format"
 dump = require "moonscript.dump"
+transform = require "moonscript.transform"
 
+import NameProxy from transform
 import reversed from util
 import ntype from require "moonscript.types"
 import concat, insert from table
 
 export line_compile
 
 line_compile =
-  raw: (node) =>
-    _, text = unpack node
-    @add text
+  raw: (node) => @add node[2]
+
+  lines: (node) =>
+    for line in *node[2]
+      @add line
 
   declare: (node) =>
     names = node[2]
@@ -82,6 +86,11 @@ line_compile =
     add_clause cond for cond in *node[4,]
     root
 
+  repeat: (node) =>
+    cond, block = unpack node, 2
+    with @block "repeat", @line "until ", @value cond
+      \stms block
+
   while: (node) =>
     _, cond, block = unpack node
 
@@ -113,10 +122,33 @@ line_compile =
       \append_list [@value exp for exp in *exps], ","
       \append " do"
 
-    with @block loop
+    continue_name = nil
+    out = with @block loop
+      \listen "continue", ->
+        unless continue_name
+          continue_name = NameProxy"continue"
+          \put_name continue_name
+        continue_name
+
       \declare names
       \stms block
 
+    -- todo: figure out how to put this in the transformer
+    if continue_name
+      out\put_name continue_name, nil
+      out\splice (lines) -> {
+        {"assign", {continue_name}, {"false"}}
+        {"repeat", "true", {
+          lines
+          {"assign", {continue_name}, {"true"}}
+        }}
+        {"if", {"not", continue_name}, {
+          {"break"}
+        }}
+      }
+
+    out
+
   export: (node) =>
     _, names = unpack node
     if type(names) == "string"

moonscript/parse.lua

@@ -368,7 +368,7 @@ local build_grammar = wrap_env(function()
 
 		NameList = Name * (sym"," * Name)^0,
 
-		BreakLoop = Ct(key"break"/trim),
+		BreakLoop = Ct(key"break"/trim) + Ct(key"continue"/trim),
 
 		Return = key"return" * (ExpListLow/mark"explist" + C"") / mark"return",
 

moonscript/transform.lua

@@ -414,6 +414,18 @@ Statement = Transformer({
     end
     return transformed or node
   end,
+  continue = function(self, node)
+    local continue_name = self:send("continue")
+    if not (continue_name) then
+      error("continue must be inside of a loop")
+    end
+    return build.group({
+      build.assign_one(continue_name, "true"),
+      {
+        "break"
+      }
+    })
+  end,
   export = function(self, node)
     if #node > 2 then
       if node[2] == "class" then

moonscript/transform.moon

@@ -181,6 +181,13 @@ Statement = Transformer {
 
     transformed or node
 
+  continue: (node) =>
+    continue_name = @send"continue"
+    error "continue must be inside of a loop" unless continue_name
+    build.group {
+      build.assign_one continue_name, "true"
+      {"break"}
+    }
 
   export: (node) =>
     -- assign values if they are included