Implement with special form

bryanjos · bryanjos · commit 5ea4512ccfb3 · 2017-07-15T23:06:49.000-05:00
diff --git a/.tool-versions b/.tool-versions
@@ -1,3 +1,3 @@
 erlang 20.0
-elixir ref-v1.5.0-rc.0
-nodejs 8.1.0
+elixir ref-v1.5.0-rc.1
+nodejs 8.1.0
diff --git a/lib/elixir_script/passes/find_used_functions.ex b/lib/elixir_script/passes/find_used_functions.ex
@@ -216,6 +216,29 @@ defmodule ElixirScript.FindUsedFunctions do
     Enum.each(clauses, &walk(&1, state))
   end
 
+  defp walk({:with, _, args}, state) do
+    Enum.each(args, fn
+      {:<-, _, [left, right]} ->
+        walk(left, state)
+        walk(right, state)
+
+      {:=, _, [left, right]} ->
+        walk(left, state)
+        walk(right, state)
+
+      [do: expression] ->
+        walk_block(expression, state)
+
+      [do: expression, else: elses] ->
+        walk_block(expression, state)
+        Enum.each(elses, fn
+          {:->, _, [left, right]} ->
+            walk(left, state)
+            walk(right, state)
+        end)
+    end)
+  end
+
   defp walk({{:., _, [:erlang, :apply]}, _, [module, function, params]}, state) do
     walk({{:., [], [module, function]}, [], params}, state)
   end
@@ -272,4 +295,4 @@ defmodule ElixirScript.FindUsedFunctions do
     end
   end
 
-end
+end
diff --git a/lib/elixir_script/passes/find_used_modules.ex b/lib/elixir_script/passes/find_used_modules.ex
@@ -234,6 +234,29 @@ defmodule ElixirScript.FindUsedModules do
     Enum.each(clauses, &walk(&1, state))
   end
 
+  defp walk({:with, _, args}, state) do
+    Enum.each(args, fn
+      {:<-, _, [left, right]} ->
+        walk(left, state)
+        walk(right, state)
+
+      {:=, _, [left, right]} ->
+        walk(left, state)
+        walk(right, state)
+
+      [do: expression] ->
+        walk_block(expression, state)
+
+      [do: expression, else: elses] ->
+        walk_block(expression, state)
+        Enum.each(elses, fn
+          {:->, _, [left, right]} ->
+            walk(left, state)
+            walk(right, state)
+        end)
+    end)
+  end
+
   defp walk({{:., _, [:erlang, :apply]}, _, [module, function, params]}, state) do
     walk({{:., [], [module, function]}, [], params}, state)
   end
@@ -289,4 +312,4 @@ defmodule ElixirScript.FindUsedModules do
     end
   end
 
-end
+end
diff --git a/lib/elixir_script/passes/translate/form.ex b/lib/elixir_script/passes/translate/form.ex
@@ -1,6 +1,6 @@
 defmodule ElixirScript.Translate.Form do
   alias ESTree.Tools.Builder, as: J
-  alias ElixirScript.Translate.Forms.{Bitstring, Match, Try, For, Receive, Remote, Pattern}
+  alias ElixirScript.Translate.Forms.{Bitstring, Match, Try, For, Receive, Remote, Pattern, With}
   alias ElixirScript.Translate.Clause
   require Logger
 
@@ -203,6 +203,10 @@ defmodule ElixirScript.Translate.Form do
     Try.compile(blocks, state)
   end
 
+  def compile({:with, _, args}, state) do
+    With.compile(args, state)
+  end
+
   def compile({:fn, _, _} = ast, state) do
     ElixirScript.Translate.Function.compile(ast, state)
   end
diff --git a/lib/elixir_script/passes/translate/forms/with.ex b/lib/elixir_script/passes/translate/forms/with.ex
@@ -0,0 +1,61 @@
+defmodule ElixirScript.Translate.Forms.With do
+  @moduledoc false
+  alias ESTree.Tools.Builder, as: JS
+  alias ElixirScript.Translate.{Function, Clause}
+  alias ElixirScript.Translate.Forms.Pattern
+
+
+  def compile(args, module_state) do
+    result = Enum.reduce(args, %{ expressions: [], arguments: [], module_state: module_state }, fn
+      {symbol, _, [pattern, body] }, state when symbol in [:<-, :=] ->
+        {ast, module_state} = Function.compile_block(body, state.module_state)
+        body = Clause.return_last_statement(ast)
+        expr_function = JS.arrow_function_expression(state.arguments, [], JS.block_statement(body))
+
+        { patterns, params, module_state } = Pattern.compile([pattern], module_state)
+
+        %{state | arguments: state.arguments ++ params,
+          expressions: state.expressions ++ [ JS.array_expression([hd(patterns), expr_function]) ],
+          module_state: module_state
+        }
+
+      [do: expr], state ->
+        expr_function = process_block(expr, state.arguments, state.module_state)
+
+        %{state | expressions: state.expressions ++ [ expr_function ] }
+      [do: do_expr, else: else_expr], state ->
+        do_function = process_block(do_expr, state.arguments, state.module_state)
+
+        { else_function, _ } = Function.compile({:fn, [], else_expr}, state.module_state)
+
+        %{state | expressions: state.expressions ++ [ do_function, else_function ] }
+    end)
+
+    expressions = result.expressions
+
+    js_ast = JS.call_expression(
+      JS.member_expression(
+        JS.member_expression(
+          JS.identifier("Bootstrap"),
+          JS.member_expression(
+            JS.identifier("Core"),
+            JS.identifier("SpecialForms")
+          )
+        ),
+        JS.identifier("_with")
+      ),
+      expressions
+    )
+
+    { js_ast, module_state }
+
+  end
+
+
+  defp process_block(body, arguments, module_state) do
+    {ast, _} = Function.compile_block(body, module_state)
+
+    body = Clause.return_last_statement(ast)
+    JS.arrow_function_expression(arguments, [], JS.block_statement(body))
+  end
+end
diff --git a/package.json b/package.json
@@ -41,9 +41,7 @@
     "sinon": "^1.17.7"
   },
   "ava": {
-    "require": [
-      "babel-register"
-    ],
+    "require": ["babel-register"],
     "babel": {
       "babelrc": true
     }
diff --git a/src/javascript/lib/core/special_forms.js b/src/javascript/lib/core/special_forms.js
@@ -151,5 +151,5 @@ export default {
   _for,
   _try,
   _with,
-  receive,
+  receive
 };
diff --git a/src/javascript/tests/with.spec.js b/src/javascript/tests/with.spec.js
@@ -1,5 +1,6 @@
 import Core from '../lib/core';
 import test from 'ava';
+
 const Patterns = Core.Patterns;
 const SpecialForms = Core.SpecialForms;
 const Tuple = Core.Tuple;
@@ -78,7 +79,7 @@ test('with bare expression', t => {
     [$, width => width * 2],
     [
       new Tuple(Symbol.for('ok'), $),
-      (width, double_width) => map_fetch(opts, 'height'),
+      (width, double_width) => map_fetch(opts, 'height')
     ],
     (width, double_width, height) =>
       new Tuple(Symbol.for('ok'), double_width * height)
diff --git a/test/support/main.ex b/test/support/main.ex
@@ -1,5 +1,15 @@
 defmodule Main do
   def start(:normal, [callback]) do
     callback.("started")
+
+    opts = %{width: 10, height: 15}
+    with {:ok, width} <- Map.fetch(opts, :width),
+         {:ok, height} <- Map.fetch(opts, :height)
+    do
+         {:ok, width * height}
+    else
+      :error ->
+       {:error, :wrong_data}
+    end
   end
 end

-Original file line number
+Diff line change
   _for,
   _try,
   _with,
 -  receive,
 +  receive
 };