Implement parser

src/Parser.php

@@ -2,6 +2,9 @@
 
 namespace Cerbero\JsonParser;
 
+use Cerbero\JsonParser\Pointers\Pointer;
+use Cerbero\JsonParser\Pointers\Pointers;
+use Generator;
 use IteratorAggregate;
 use Traversable;
 
@@ -11,6 +14,27 @@ use Traversable;
  */
 class Parser implements IteratorAggregate
 {
+    /**
+     * The JSON parsing state.
+     *
+     * @var State
+     */
+    protected State $state;
+
+    /**
+     * The JSON pointers collection.
+     *
+     * @var Pointers
+     */
+    protected Pointers $pointers;
+
+    /**
+     * The JSON pointer matching the current tree.
+     *
+     * @var Pointer
+     */
+    protected Pointer $pointer;
+
     /**
      * Instantiate the class.
      *
@@ -19,6 +43,9 @@ class Parser implements IteratorAggregate
      */
     public function __construct(protected Lexer $lexer, protected Config $config)
     {
+        $this->state = new State();
+        $this->pointers = new Pointers(...$config->pointers);
+        $this->pointer = $this->pointers->matchTree($this->state->tree);
     }
 
     /**
@@ -29,7 +56,96 @@ class Parser implements IteratorAggregate
     public function getIterator(): Traversable
     {
         foreach ($this->lexer as $token) {
-            //
+            $this->rematchPointer();
+            $this->traverseToken($token);
+            $this->bufferToken($token);
+            $this->mutateState($token);
+
+            if ($this->state->depth > $this->pointer->depth()) {
+                continue;
+            }
+
+            if ($this->state->buffer != '') {
+                yield from $this->yieldDecodedBuffer();
+            }
+
+            if ($this->pointers->wereFound() && !$this->pointer->includesTree($this->tree)) {
+                break;
+            }
+        }
+    }
+
+    /**
+     * Set the matching JSON pointer when the tree changes
+     *
+     * @return void
+     */
+    protected function rematchPointer(): void
+    {
+        if ($this->state->treeChanged && $this->pointers->count() > 1) {
+            $this->pointer = $this->pointers->matchTree($this->state->tree);
+            $this->state->treeChanged = false;
+        }
+    }
+
+    /**
+     * Keep track of the JSON tree when traversing the given token
+     *
+     * @param Token $token
+     * @return void
+     */
+    protected function traverseToken(Token $token): void
+    {
+        if (!$this->state->inObject && $token instanceof Value && $this->state->depth < $this->pointer->depth()) {
+            $this->state->treeChanged = true;
+            $this->state->tree->traverse($token);
+        }
+    }
+
+    /**
+     * Preserve the given token in the buffer
+     *
+     * @param Token $token
+     * @return void
+     */
+    protected function bufferToken(Token $token): void
+    {
+        if ($this->pointer->matchesTree($this->state->tree) && $this->shouldBufferToken($token)) {
+            $this->state->buffer .= $token;
+        }
+    }
+
+    /**
+     * Preserve the given token in the buffer
+     *
+     * @param Token $token
+     * @return void
+     */
+    protected function mutateState(Token $token): void
+    {
+        if ($token instanceof StateMutator) {
+            $token->mutateState($this->state);
+        }
+    }
+
+    /**
+     * Yield the decoded JSON of the buffer
+     *
+     * @return Generator
+     */
+    protected function yieldDecodedBuffer(): Generator
+    {
+        $decoded = $this->config->decoder->decode($this->state->buffer);
+        $this->state->buffer = '';
+
+        if (!$decoded->succeeded) {
+            call_user_func($this->config->onError, $decoded);
+        }
+
+        if ($this->state->inObject) {
+            yield $this->state->tree[$this->state->depth] => $decoded->value;
+        } else {
+            yield $decoded->value;
         }
     }
 }