Early draft of a data sampler iterator.

An easy way to iterate over data described by Praspel.

1 files changed, 226 insertions, 0 deletions

diff --git a/Iterator/Sampler.php b/Iterator/Sampler.php
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+<?php
+
+/**
+ * Hoa
+ *
+ *
+ * @license
+ *
+ * New BSD License
+ *
+ * Copyright © 2007-2013, Ivan Enderlin. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the Hoa nor the names of its contributors may be
+ *       used to endorse or promote products derived from this software without
+ *       specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+namespace Hoa\Praspel\Iterator {
+
+/**
+ * Class \Hoa\Praspel\Iterator\Sampler.
+ *
+ * An easy way to iterate over data described by Praspel.
+ *
+ * @author     Ivan Enderlin <ivan.enderlin@hoa-project.net>
+ * @copyright  Copyright © 2007-2013 Ivan Enderlin.
+ * @license    New BSD License
+ */
+
+class Sampler implements \Iterator {
+
+    /**
+     * Key value is variable name.
+     *
+     * @const int
+     */
+    const KEY_AS_VARIABLE_NAME     = 0;
+
+    /**
+     * Key value is variable position.
+     *
+     * @const int
+     */
+    const KEY_AS_VARIABLE_POSITION = 1;
+
+    /**
+     * Declaration.
+     *
+     * @var \Hoa\Praspel\Model\Declaration object
+     */
+    protected $_declaration = null;
+
+    /**
+     * Max number of data to generate.
+     *
+     * @var \Hoa\Praspel\Iterator\Sampler int
+     */
+    protected $_maxData     = null;
+
+    /**
+     * Key type (please, see self::KEY_AS_* constants).
+     *
+     * @var \Hoa\Praspel\Iterator\Sampler int
+     */
+    protected $_keyType     = null;
+
+    /**
+     * Variables to consider.
+     *
+     * @var \Hoa\Praspel\Iterator\Sampler array
+     */
+    protected $_variables   = array();
+
+    /**
+     * Current key.
+     *
+     * @var \Hoa\Praspel\Iterator\Sampler int
+     */
+    protected $_key         = -1;
+
+    /**
+     * Current value.
+     *
+     * @var \Hoa\Praspel\Iterator\Sampler array
+     */
+    protected $_current     = null;
+
+
+
+    /**
+     * Construct.
+     *
+     * @access  public
+     * @param   \Hoa\Praspel\Model\Declaration  $declaration    Declaration.
+     * @param   int                             $maxData        Maximum data to
+     *                                                          sample.
+     * @param   int                             $keyType        Key type (plese,
+     *                                                          see
+     *                                                          self::KEY_AS*
+     *                                                          constants).
+     * @return  void
+     */
+    public function __construct ( \Hoa\Praspel\Model\Declaration $declaration,
+                                  $maxData = 5,
+                                  $keyType = self::KEY_AS_VARIABLE_NAME ) {
+
+        $this->_declaration = $declaration;
+        $this->_maxData     = $maxData;
+        $this->_keyType     = $keyType;
+
+        return;
+    }
+
+    /**
+     * Consider some variables.
+     * Example:
+     *     $this->extract('x', 'y', 'z')
+     *
+     * @access  public
+     * @param   string  $variable    Variable name.
+     * @param   ...     ...          ...
+     * @return  \Hoa\Praspel\Iterator\Sampler
+     */
+    public function extract ( ) {
+
+        foreach(func_get_args() as $variable)
+            $this->_variables[] = $this->_declaration[$variable];
+
+        return $this;
+    }
+
+    /**
+     * Get current value.
+     *
+     * @access  public
+     * @return  array
+     */
+    public function current ( ) {
+
+        return $this->_current;
+    }
+
+    /**
+     * Get current key.
+     *
+     * @access  public
+     * @return  int
+     */
+    public function key ( ) {
+
+        return $this->_key;
+    }
+
+    /**
+     * Compute the next value and return it.
+     *
+     * @access  public
+     * @return  array
+     */
+    public function next ( ) {
+
+        $handle = array();
+
+        if(empty($this->_variables))
+            $this->_variables = $this->_declaration->getLocalVariables();
+
+        if(self::KEY_AS_VARIABLE_NAME === $this->_keyType)
+            foreach($this->_variables as $variable)
+                $handle[$variable->getName()] = $variable->sample();
+        else
+            foreach($this->_variables as $variable)
+                $handle[] = $variable->sample();
+
+        ++$this->_key;
+        $this->_current = $handle;
+
+        return $this->current();
+    }
+
+    /**
+     * Rewind the iterator.
+     *
+     * @access  public
+     * @return  void
+     */
+    public function rewind ( ) {
+
+        $this->_key     = -1;
+        $this->_current = null;
+        $this->next();
+
+        return;
+    }
+
+    /**
+     * Check if there is enough data to continue.
+     *
+     * @access  public
+     * @return  bool
+     */
+    public function valid ( ) {
+
+        return $this->_key < $this->_maxData;
+    }
+}
+
+}