Implement new static analysis tools and infrastructure for expression trees

CHANGELOG.md

@@ -101,6 +101,7 @@ dev-master
     - Extracted interfaces from `Request`/`Operation`/`Segment` visitor classes.
  - Removed obsolete query providers (`Loadable`, `Caching`) in favour of a new integrated helper `Providers\Utilities\IQueryResultCollection`
  - Implemented new DSL query provider under `Providers\DSL`.
+ - Implemented new static analysis tools and infrastructure for expression trees under the `Analysis` namespace.
  - New structure of query providers
     - `RepositoryProvider` decorates the `QueryProvider`
     - New configuration classes (under `Providers\Configuration` namespace)

Source/Analysis/AnalysisContext.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace Pinq\Analysis;
+
+use Pinq\Expressions as O;
+
+/**
+ * Implementation of the analysis context.
+ *
+ * @author Elliot Levin <elliotlevin@hotmail.com>
+ */
+class AnalysisContext extends Typed implements IAnalysisContext
+{
+    /**
+     * @var O\IEvaluationContext
+     */
+    protected $evaluationContext;
+
+    /**
+     * @var IType[]
+     */
+    protected $expressionTypes = [];
+
+    public function __construct(ITypeSystem $typeSystem, O\IEvaluationContext $evaluationContext)
+    {
+        parent::__construct($typeSystem);
+        $this->evaluationContext = $evaluationContext;
+        foreach($evaluationContext->getVariableTable() as $variable => $value) {
+            $this->setExpressionType(O\Expression::variable(O\Expression::value($variable)), $typeSystem->getTypeFromValue($value));
+        }
+    }
+
+    public function getEvaluationContext()
+    {
+        return $this->evaluationContext;
+    }
+
+    public function getExpressionType(O\Expression $expression)
+    {
+        $hash = $expression->hash();
+        return isset($this->expressionTypes[$hash]) ? $this->expressionTypes[$hash] : null;
+    }
+
+    public function setExpressionType(O\Expression $expression, IType $type)
+    {
+        $this->expressionTypes[$expression->hash()] = $type;
+    }
+
+    public function removeExpressionType(O\Expression $expression)
+    {
+        unset($this->expressionTypes[$expression->hash()]);
+    }
+
+    public function createReference(O\Expression $expression, O\Expression $referencedExpression)
+    {
+        $this->expressionTypes[$expression->hash()] =& $this->expressionTypes[$referencedExpression->hash()];
+    }
+
+    public function inNewScope()
+    {
+        return new self($this->typeSystem, $this->evaluationContext);
+    }
+}

Source/Analysis/BinaryOperations/BinaryOperation.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace Pinq\Analysis\BinaryOperations;
+
+use Pinq\Analysis\IBinaryOperation;
+use Pinq\Analysis\ITypeSystem;
+use Pinq\Analysis\Typed;
+use Pinq\Expressions as O;
+
+/**
+ * Implementation of the binary operation.
+ *
+ * @author Elliot Levin <elliotlevin@hotmail.com>
+ */
+class BinaryOperation extends Typed implements IBinaryOperation
+{
+    /**
+     * @var string
+     */
+    protected $leftOperandType;
+
+    /**
+     * @var int
+     */
+    protected $operator;
+
+    /**
+     * @var string
+     */
+    protected $rightOperandType;
+
+    /**
+     * @var string
+     */
+    protected $returnType;
+
+    public function __construct(ITypeSystem $typeSystem, $leftOperandType, $operator, $rightOperandType, $returnType)
+    {
+        parent::__construct($typeSystem);
+        $this->leftOperandType  = $leftOperandType;
+        $this->operator         = $operator;
+        $this->rightOperandType = $rightOperandType;
+        $this->returnType       = $returnType;
+    }
+
+    public function getLeftOperandType()
+    {
+        return $this->typeSystem->getType($this->leftOperandType);
+    }
+
+    public function getOperator()
+    {
+        return $this->operator;
+    }
+
+    public function getRightOperandType()
+    {
+        return $this->typeSystem->getType($this->rightOperandType);
+    }
+
+    public function getReturnType()
+    {
+        return $this->typeSystem->getType($this->returnType);
+    }
+}