Fixes PY-105: "with" statement becomes a name definer and resolutions to its 'as' name works.

python/src/com/jetbrains/python/parsing/StatementParsing.java

@@ -586,7 +586,7 @@ public class StatementParsing
     getExpressionParser().parseExpression();
     if (myBuilder.getTokenType() == PyTokenTypes.AS_KEYWORD) {
       myBuilder.advanceLexer();
-      getExpressionParser().parseExpression();
+      getExpressionParser().parseExpression(true, true); // 'as' is followed by a target
     }
     checkMatches(PyTokenTypes.COLON, "colon expected");
     parseSuite();

python/src/com/jetbrains/python/psi/PyWithStatement.java

@@ -3,5 +3,5 @@ package com.jetbrains.python.psi;
 /**
  * @author yole
  */
-public interface PyWithStatement extends PyStatement {
+public interface PyWithStatement extends PyStatement, NameDefiner {
 }

python/src/com/jetbrains/python/psi/impl/PyWithStatementImpl.java

@@ -1,8 +1,11 @@
 package com.jetbrains.python.psi.impl;
 
 import com.intellij.lang.ASTNode;
-import com.jetbrains.python.psi.PyElementVisitor;
-import com.jetbrains.python.psi.PyWithStatement;
+import com.intellij.psi.PsiElement;
+import com.jetbrains.python.psi.*;
+import com.jetbrains.python.PyElementTypes;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author yole
@@ -15,4 +18,26 @@ public class PyWithStatementImpl extends PyElementImpl implements PyWithStatemen
   protected void acceptPyVisitor(final PyElementVisitor pyVisitor) {
     pyVisitor.visitPyWithStatement(this);
   }
+
+  @Nullable
+  public PyExpression getTargetExpression() {
+    final ASTNode asNameNode = getNode().findChildByType(PyElementTypes.TARGET_EXPRESSION);
+    if (asNameNode == null) return null;
+    return (PyTargetExpression)asNameNode.getPsi();
+  }
+
+  @NotNull
+  public Iterable<PyElement> iterateNames() {
+    PyElement ret = getTargetExpression();
+    return new SingleIterable<PyElement>(ret);
+  }
+
+  public PsiElement getElementNamed(final String the_name) {
+    PyElement named_elt = IterHelper.findName(iterateNames(), the_name);
+    return named_elt;
+  }
+
+  public boolean mustResolveOutside() {
+    return false;
+  }
 }

python/testData/psi/WithStatement.txt

@@ -19,7 +19,7 @@ PyFile:WithStatement.py
     PsiWhiteSpace(' ')
     PsiElement(Py:AS_KEYWORD)('as')
     PsiWhiteSpace(' ')
-    PyReferenceExpression: y
+    PyTargetExpression: y
       PsiElement(Py:IDENTIFIER)('y')
     PsiElement(Py:COLON)(':')
     PsiWhiteSpace('\n  ')

python/testData/psi/WithStatement2.txt

@@ -55,7 +55,7 @@ PyFile:WithStatement2.py
     PsiWhiteSpace(' ')
     PsiElement(Py:AS_KEYWORD)('as')
     PsiWhiteSpace(' ')
-    PyReferenceExpression: y
+    PyTargetExpression: y
       PsiElement(Py:IDENTIFIER)('y')
     PsiElement(Py:COLON)(':')
     PsiWhiteSpace(' ')

python/testData/resolve/WithStatement.py

@@ -0,0 +1,3 @@
+from __future__ import with_statement
+with None as boom:
+  <ref>boom + 1

python/testSrc/com/jetbrains/python/PyResolveTest.java

@@ -140,6 +140,11 @@ public class PyResolveTest extends ResolveTestCase {
     assertNotNull(PsiTreeUtil.getParentOfType(targetElement, PyAssignmentStatement.class)); // it's deep in a tuple
   }
 
+  public void testWithStatement() throws Exception {
+    PsiElement targetElement = resolve();
+    assertTrue(targetElement instanceof PyTargetExpression);
+    assertTrue(targetElement.getParent() instanceof PyWithStatement);
+  }
 
 
   @Override