Start implementing list references

src/Target/Php70.php

@@ -12,7 +12,7 @@ use Phabel\Target\Php70\IssetExpressionFixer;
 use Phabel\Target\Php70\NestedExpressionFixer;
 use Phabel\Target\Php70\NullCoalesceReplacer;
 use Phabel\Target\Php70\ReservedNameReplacer;
-use Phabel\Target\Php70\ScalarTypeHintsRemover;
+use Phabel\Target\Php70\ScalarTypeHints;
 use Phabel\Target\Php70\SpaceshipOperatorReplacer;
 use Phabel\Target\Php70\StrictTypesDeclareStatementRemover;
 use Phabel\Target\Php70\ThrowableReplacer;
@@ -42,7 +42,7 @@ class Php70 extends Plugin
             GroupUseReplacer::class,
             NullCoalesceReplacer::class,
             ReservedNameReplacer::class,
-            ScalarTypeHintsRemover::class,
+            ScalarTypeHints::class,
             SpaceshipOperatorReplacer::class,
             StrictTypesDeclareStatementRemover::class,
             ThrowableReplacer::class,

src/Target/Php70/ScalarTypeHints.php

@@ -9,7 +9,7 @@ use Phabel\Plugin\TypeHintStripper;
  * @author Daniil Gentili <daniil@daniil.it>
  * @license MIT
  */
-class ScalarTypeHintsRemover extends Plugin
+class ScalarTypeHints extends Plugin
 {
     /**
      * Alias.

src/Target/Php71.php

@@ -6,6 +6,7 @@ use Phabel\Plugin;
 use Phabel\Target\Php71\ArrayList;
 use Phabel\Target\Php71\ClassConstantVisibilityModifiersRemover;
 use Phabel\Target\Php71\IssetExpressionFixer;
+use Phabel\Target\Php71\IterableHint;
 use Phabel\Target\Php71\ListKey;
 use Phabel\Target\Php71\MultipleCatchReplacer;
 use Phabel\Target\Php71\NestedExpressionFixer;
@@ -32,6 +33,7 @@ class Php71 extends Plugin
             ArrayList::class,
             ClassConstantVisibilityModifiersRemover::class,
             ListKey::class,
+            IterableHint::class,
             MultipleCatchReplacer::class,
             VoidReturnType::class,
             NullableType::class

src/Target/Php71/IterableHint.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Phabel\Target\Php71;
+
+use Phabel\Plugin;
+use Phabel\Plugin\TypeHintStripper;
+
+/**
+ * @author Daniil Gentili <daniil@daniil.it>
+ * @license MIT
+ */
+class IterableHint extends Plugin
+{
+    /**
+     * Alias.
+     *
+     * @return array
+     */
+    public static function runAfter(): array
+    {
+        return [
+            TypeHintStripper::class => [
+                'types' => ['iterable']
+            ]
+        ];
+    }
+}

src/Target/Php73/ListReference.php

@@ -0,0 +1,95 @@
+<?php
+
+namespace Phabel\Target\Php73;
+
+use Phabel\Context;
+use Phabel\Plugin;
+use PhpParser\Node\Expr\Array_;
+use PhpParser\Node\Expr\ArrayDimFetch;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\AssignRef;
+use PhpParser\Node\Expr\List_;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt\Foreach_;
+
+/**
+ * Polyfills list assignment by reference.
+ */
+class ListReference extends Plugin
+{
+    /**
+     * Parse list foreach with custom keys.
+     *
+     * @param Foreach_ $node Foreach
+     *
+     * @return void
+     */
+    public function enterForeach(Foreach_ $node, Context $ctx): void
+    {
+        if (!($node->valueVar instanceof List_ || $node->valueVar instanceof Array_) || !$this->shouldSplit($node->valueVar)) {
+            return;
+        }
+        $list = $node->valueVar;
+        $var = $node->valueVar = $ctx->getVariable();
+        $assignments = self::splitList($list, $var);
+        $node->stmts
+    }
+    /**
+     * Parse list assignment with custom keys.
+     *
+     * @param Assign $node List assignment
+     *
+     * @return void
+     */
+    public function enterAssign(Assign $node, Context $ctx): void
+    {
+        if (!($node->var instanceof List_ || $node->var instanceof Array_) || !$this->shouldSplit($node->var)) {
+            return;
+        }
+        [$node->var, $array] = $this->splitList($node->var, $ctx);
+        $node->expr = self::callPoly('destructure', $array, $node->expr);
+    }
+    /**
+     * Split referenced list into multiple assignments.
+     *
+     * @param Array_|List_ $list List
+     * @param Variable     $var  Variable
+     *
+     * @return (Assign|AssignRef)[]
+     */
+    private static function splitList($list, Variable $var): array
+    {
+        $assignments = [];
+        $key = 0; // Technically a list assignment does not support mixed keys, but we need this for nested assignments
+        foreach ($list->items as $item) {
+            if (!$item) {
+                continue;
+            }
+            $curKey = $item->key ?? $key++;
+            if ($item->value instanceof List_ || $item->value instanceof Array_) {
+                // Do nothing, will re-split later if needed
+            } else if ($item->byRef) {
+                $assignments []= new AssignRef($item->value, new ArrayDimFetch($var, $curKey));
+            } else {
+                $assignments []= new Assign($item->value, new ArrayDimFetch($var, $curKey));
+            }
+        }
+        return $assignments;
+    }
+    /**
+     * Whether this is a referenced list.
+     *
+     * @param List_|Array_ $list List
+     *
+     * @return boolean
+     */
+    private function shouldSplit($list): bool
+    {
+        foreach ($list->items ?? [] as $item) {
+            if ($item->byRef) {
+                return true;
+            }
+        }
+        return false;
+    }
+}