From 5228af041e66dbe72ab49767213e5a461be648d0 Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Mon, 24 Aug 2020 12:25:35 +0200
Subject: [PATCH] Regenerator progress

---
 src/Plugin/ReGenerator.php                    | 22 +++++++
 .../ReGenerator/ReGenerator.php               | 24 ++++----
 src/Target/Php55/YieldDetector.php            | 30 ++++++++++
 src/Target/Php70/YieldFromReplacer.php        | 42 -------------
 src/Target/Php70/YieldFromReturnDetector.php  | 59 +++++++++++++++++++
 5 files changed, 123 insertions(+), 54 deletions(-)
 create mode 100644 src/Plugin/ReGenerator.php
 rename src/{Target/Php70 => Plugin}/ReGenerator/ReGenerator.php (89%)
 create mode 100644 src/Target/Php55/YieldDetector.php
 delete mode 100644 src/Target/Php70/YieldFromReplacer.php
 create mode 100644 src/Target/Php70/YieldFromReturnDetector.php

diff --git a/src/Plugin/ReGenerator.php b/src/Plugin/ReGenerator.php
new file mode 100644
index 0000000..8bf12dc
--- /dev/null
+++ b/src/Plugin/ReGenerator.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Phabel\Plugin;
+
+use Phabel\Plugin;
+use PhpParser\Builder\FunctionLike;
+
+class ReGenerator extends Plugin
+{
+    const SHOULD_ATTRIBUTE = 'shouldRegenerate';
+    public function enter(FunctionLike $function)
+    {
+        if (!$function->getAttribute(self::SHOULD_ATTRIBUTE, false)) {
+            return;
+        }
+        
+    }
+    public function runAfter(): array
+    {
+        return [ArrowClosure::class];
+    }
+}
diff --git a/src/Target/Php70/ReGenerator/ReGenerator.php b/src/Plugin/ReGenerator/ReGenerator.php
similarity index 89%
rename from src/Target/Php70/ReGenerator/ReGenerator.php
rename to src/Plugin/ReGenerator/ReGenerator.php
index 8b16ecb..8f061f6 100644
--- a/src/Target/Php70/ReGenerator/ReGenerator.php
+++ b/src/Plugin/ReGenerator/ReGenerator.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Phabel\Target\Php70\ReGenerator;
+namespace Phabel\Plugin\ReGenerator;
 
 /**
  * Regenerator class.
@@ -65,7 +65,7 @@ class ReGenerator implements \Iterator
     /**
      * Yielded from (re)generator.
      *
-     * @var \Generator|self
+     * @var \Generator|self|null
      */
     private $yieldedFrom;
 
@@ -82,7 +82,7 @@ class ReGenerator implements \Iterator
     /**
      * Get return value.
      *
-     * @return void
+     * @return mixed
      */
     public function getReturn()
     {
@@ -97,7 +97,7 @@ class ReGenerator implements \Iterator
     private function start(): void
     {
         if (!$this->started) {
-            ($this->generator)($this->state, $this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned);
+            ($this->generator)($this->state, $this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned, $this->yieldedFrom);
             $this->started = true;
         }
     }
@@ -112,9 +112,9 @@ class ReGenerator implements \Iterator
                 $e = $exception;
             }
             if (!$this->yieldedFrom->valid()) { // Returned from yield from
-                $returnValue = $this->yieldedFrom->getReturn();
+                $returnValue = \method_exists($this->yieldedFrom, 'getReturn') ? $this->yieldedFrom->getReturn() : null;
                 $this->yieldedFrom = null;
-                if ($e) {
+                if (isset($e)) {
                     return $this->throw($e);
                 }
                 return $this->send($returnValue);
@@ -125,7 +125,7 @@ class ReGenerator implements \Iterator
         if (!$this->returned) {
             $this->sentValue = $value;
             try {
-                ($this->generator)($this->state, $this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned);
+                ($this->generator)($this->state, $this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned, $this->yieldedFrom);
             } catch (\Throwable $e) {
                 $this->returned = true;
                 throw $e;
@@ -145,9 +145,9 @@ class ReGenerator implements \Iterator
                 $e = $exception;
             }
             if (!$this->yieldedFrom->valid()) { // Returned from yield from
-                $returnValue = $this->yieldedFrom->getReturn();
+                $returnValue = \method_exists($this->yieldedFrom, 'getReturn') ? $this->yieldedFrom->getReturn() : null;
                 $this->yieldedFrom = null;
-                if ($e) {
+                if (isset($e)) {
                     return $this->throw($e);
                 }
                 return $this->send($returnValue);
@@ -158,7 +158,7 @@ class ReGenerator implements \Iterator
         if (!$this->returned) {
             $this->sentException = $value;
             try {
-                ($this->generator)($this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned);
+                ($this->generator)($this->variables, $this->yieldKey, $this->yieldValue, $this->sentValue, $this->sentException, $this->returnValue, $this->returned, $this->yieldedFrom);
             } catch (\Throwable $e) {
                 $this->returned = true;
                 throw $e;
@@ -171,18 +171,18 @@ class ReGenerator implements \Iterator
 
     public function current()
     {
-        $this->start();
         if ($this->yieldedFrom) {
             return $this->yieldedFrom->current();
         }
+        $this->start();
         return $this->yieldValue;
     }
     public function key()
     {
-        $this->start();
         if ($this->yieldedFrom) {
             return $this->yieldedFrom->key();
         }
+        $this->start();
         return $this->yieldKey;
     }
     public function next(): void
diff --git a/src/Target/Php55/YieldDetector.php b/src/Target/Php55/YieldDetector.php
new file mode 100644
index 0000000..2090332
--- /dev/null
+++ b/src/Target/Php55/YieldDetector.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Phabel\Target\Php55;
+
+use Phabel\Context;
+use Phabel\Plugin;
+use Phabel\Plugin\ReGenerator;
+use PhpParser\Node\Expr\Yield_;
+use PhpParser\Node\FunctionLike;
+
+class YieldDetector extends Plugin
+{
+    public function enterYield(Yield_ $node, Context $ctx): void
+    {
+        foreach ($ctx->parents as $parent) {
+            if ($parent instanceof FunctionLike) {
+                $parent->setAttribute(ReGenerator::SHOULD_ATTRIBUTE, true);
+                return;
+            }
+        }
+    }
+    public function runBefore(): array
+    {
+        return [ReGenerator::class];
+    }
+    public function runAfter(): array
+    {
+        return [ArrowClosure::class];
+    }
+}
diff --git a/src/Target/Php70/YieldFromReplacer.php b/src/Target/Php70/YieldFromReplacer.php
deleted file mode 100644
index d59e826..0000000
--- a/src/Target/Php70/YieldFromReplacer.php
+++ /dev/null
@@ -1,42 +0,0 @@
-<?php
-
-namespace Phabel\Target\Php70;
-
-use Phabel\Context;
-use Phabel\Plugin;
-use PhpParser\Node;
-use PhpParser\Node\Expr\Assign;
-use PhpParser\Node\Expr\Instanceof_;
-use PhpParser\Node\Expr\MethodCall;
-use PhpParser\Node\Expr\Variable;
-use PhpParser\Node\Expr\YieldFrom;
-use PhpParser\Node\Identifier;
-use PhpParser\Node\Name\FullyQualified;
-use PhpParser\Node\Stmt\If_;
-use PhpParser\Node\Stmt\While_;
-
-class YieldFromReplacer extends Plugin
-{
-    private string $phabelVar = '';
-    private int $phabelCount = 0;
-    public function shouldRunFile(string $file): bool
-    {
-        $this->phabelVar = 'phabelGeneratorYieldFrom'.\hash('sha256', $file);
-        return parent::shouldRunFile($file);
-    }
-    public function enterNode(YieldFrom $node, Context $ctx)
-    {
-        $var = new Variable($this->phabelVar.($this->phabelCount++));
-        $assign = new Assign($var, $node->expr);
-        $ifInstanceof = new If_(new Instanceof_(Plugin::callMethod($var, 'valid'), new FullyQualified(\YieldReturnValue::class)), ['stmts' => [new Assign()]]);
-        $while = new While_(new MethodCall($var, new Identifier('valid')));
-        foreach ($ctx->parents as $node) {
-            if ($node->hasAttribute('currentNodeIndex')) {
-                $ctx->insertBefore($node, $node->expr);
-            }
-        }
-        $generator = $node->expr;
-
-        return new Node\Expr\Yield_($generator);
-    }
-}
diff --git a/src/Target/Php70/YieldFromReturnDetector.php b/src/Target/Php70/YieldFromReturnDetector.php
new file mode 100644
index 0000000..2334f2a
--- /dev/null
+++ b/src/Target/Php70/YieldFromReturnDetector.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Phabel\Target\Php70;
+
+use Phabel\Context;
+use Phabel\Plugin;
+use Phabel\Plugin\ReGenerator;
+use PhpParser\Node\Expr\Yield_;
+use PhpParser\Node\Expr\YieldFrom;
+use PhpParser\Node\FunctionLike;
+use PhpParser\Node\Stmt\Return_;
+
+class YieldFromReturnDetector extends Plugin
+{
+    public function enterYieldFrom(YieldFrom $node, Context $ctx): void
+    {
+        foreach ($ctx->parents as $parent) {
+            if ($parent instanceof FunctionLike) {
+                $parent->setAttribute(ReGenerator::SHOULD_ATTRIBUTE, true);
+                return;
+            }
+        }
+    }
+    public function enterYield(Yield_ $node, Context $ctx): void
+    {
+        foreach ($ctx->parents as $parent) {
+            if ($parent instanceof FunctionLike) {
+                $parent->setAttribute('hasYield', true);
+                if ($parent->getAttribute('hasReturn')) {
+                    $parent->setAttribute(ReGenerator::SHOULD_ATTRIBUTE, true);
+                }
+                return;
+            }
+        }
+    }
+    public function enterReturn(Return_ $node, Context $ctx): void
+    {
+        if (!$node->expr) {
+            return;
+        }
+        foreach ($ctx->parents as $parent) {
+            if ($parent instanceof FunctionLike) {
+                $parent->setAttribute('hasReturn', true);
+                if ($parent->getAttribute('hasYield')) {
+                    $parent->setAttribute(ReGenerator::SHOULD_ATTRIBUTE, true);
+                }
+                return;
+            }
+        }
+    }
+    public function runBefore(): array
+    {
+        return [ReGenerator::class];
+    }
+    public function runAfter(): array
+    {
+        return [ArrowClosure::class];
+    }
+}