Index: src/main/java/uk/co/badgersinfoil/metaas/dom/ASExpressionStatement.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/dom/ASExpressionStatement.java	(revision 575)
+++ src/main/java/uk/co/badgersinfoil/metaas/dom/ASExpressionStatement.java	(working copy)
@@ -17,6 +17,11 @@
 public interface ASExpressionStatement extends Statement {
 
 	/**
+	 * Returns the expression this statement would evaluate when run.
+	 */
+	public ASExpression getExpression();
+	
+	/**
 	 * Returns a string representation of the expression this statement
 	 * would evaluate when run.
 	 */
Index: src/main/java/uk/co/badgersinfoil/metaas/dom/ASAssignmentExpression.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/dom/ASAssignmentExpression.java	(revision 0)
+++ src/main/java/uk/co/badgersinfoil/metaas/dom/ASAssignmentExpression.java	(revision 0)
@@ -0,0 +1,46 @@
+package uk.co.badgersinfoil.metaas.dom;
+
+public interface ASAssignmentExpression extends ASExpression {
+	public Op getOperator();
+	public void setOperator(Op operator);
+	public ASExpression getLeftSubexpression();
+	public void setLeftSubexpression(ASExpression left);
+	public ASExpression getRightSubexpression();
+	public void setRightSubexpression(ASExpression right);
+
+	public static class Op {
+		private String name;
+		private Op(String name) {
+			this.name = name;
+		}
+		
+		/** '+=' */
+		public static final Op ADD_ASSIGN = new Op("ADD_ASSIGN");
+		/** Assignment '=' */
+		public static final Op ASSIGN = new Op("ASSIGN");
+		/** '&=' */
+		public static final Op BITAND_ASSIGN = new Op("BITAND_ASSIGN");
+		/** '|=' */
+		public static final Op BITOR_ASSIGN = new Op("BITOR_ASSIGN");
+		/** '^=' */
+		public static final Op BITXOR_ASSIGN = new Op("BITXOR_ASSIGN");
+		/** '/=' */
+		public static final Op DIV_ASSIGN = new Op("DIV_ASSIGN");
+		/** '%=' */
+		public static final Op MOD_ASSIGN = new Op("MOD_ASSIGN");
+		/** '*=' */
+		public static final Op MUL_ASSIGN = new Op("MUL_ASSIGN");
+		/** Left Shift Assigment '<<=' */
+		public static final Op SL_ASSIGN = new Op("SL_ASSIGN");
+		/** Right Shift Assigment '>>=' */
+		public static final Op SR_ASSIGN = new Op("SR_ASSIGN");
+		/** Unsigned Right Shift Assigment '>>>=' */
+		public static final Op SRU_ASSIGN = new Op("SRU_ASSIGN");
+		/** '-=' */
+		public static final Op SUB_ASSIGN = new Op("SUB_ASSIGN");
+		
+		public String toString() {
+			return name;
+		}
+	}
+}
\ No newline at end of file
Index: src/main/java/uk/co/badgersinfoil/metaas/impl/ExpressionBuilder.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/impl/ExpressionBuilder.java	(revision 575)
+++ src/main/java/uk/co/badgersinfoil/metaas/impl/ExpressionBuilder.java	(working copy)
@@ -18,6 +18,19 @@
 			case AS3Parser.TRUE:
 			case AS3Parser.FALSE:
 				return new ASTASBooleanLiteral(ast);
+			case AS3Parser.PLUS_ASSIGN:
+			case AS3Parser.ASSIGN:
+			case AS3Parser.BAND_ASSIGN:
+			case AS3Parser.BOR_ASSIGN:
+			case AS3Parser.BXOR_ASSIGN:
+			case AS3Parser.DIV_ASSIGN:
+			case AS3Parser.MOD_ASSIGN:
+			case AS3Parser.STAR_ASSIGN:
+			case AS3Parser.SL_ASSIGN:
+			case AS3Parser.SR_ASSIGN:
+			case AS3Parser.BSR_ASSIGN:
+			case AS3Parser.MINUS_ASSIGN:
+				return new ASTASAssignmentExpression(ast);
 			case AS3Parser.PLUS:
 			case AS3Parser.LAND:
 			case AS3Parser.BAND:
Index: src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASAssignmentExpression.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASAssignmentExpression.java	(revision 0)
+++ src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASAssignmentExpression.java	(revision 0)
@@ -0,0 +1,45 @@
+package uk.co.badgersinfoil.metaas.impl;
+
+import uk.co.badgersinfoil.metaas.dom.ASAssignmentExpression;
+import uk.co.badgersinfoil.metaas.dom.ASExpression;
+import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListTree;
+
+public class ASTASAssignmentExpression extends ASTASExpression
+                                   implements ASAssignmentExpression
+{
+	public ASTASAssignmentExpression(LinkedListTree ast) {
+		super(ast);
+	}
+
+	public ASExpression getLeftSubexpression() {
+		return ExpressionBuilder.build(ast.getFirstChild());
+	}
+
+	public Op getOperator() {
+		return AssignmentOperatorMap.opFromType(ast.getType());
+	}
+
+	public ASExpression getRightSubexpression() {
+		return ExpressionBuilder.build(ast.getLastChild());
+	}
+
+	public void setLeftSubexpression(ASExpression left) {
+		setSubexpression(0, left);
+	}
+
+	public void setOperator(Op operator) {
+		AssignmentOperatorMap.initialiseFromOp(operator, ast.getToken());
+	}
+
+	public void setRightSubexpression(ASExpression right) {
+		setSubexpression(1, right);
+	}
+
+	private void setSubexpression(int index, ASExpression subexpression) {
+		ASTASExpression sub = (ASTASExpression)subexpression;
+		LinkedListTree subExpr = sub.getAST();
+		ASTBuilder.assertNoParent("expression", subExpr);
+		// TODO: handle operator precedence issues
+		ast.setChildWithTokens(index, subExpr);
+	}
+}
\ No newline at end of file
Index: src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASExpressionStatement.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASExpressionStatement.java	(revision 575)
+++ src/main/java/uk/co/badgersinfoil/metaas/impl/ASTASExpressionStatement.java	(working copy)
@@ -1,5 +1,6 @@
 package uk.co.badgersinfoil.metaas.impl;
 
+import uk.co.badgersinfoil.metaas.dom.ASExpression;
 import uk.co.badgersinfoil.metaas.dom.ASExpressionStatement;
 import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListTree;
 
@@ -11,6 +12,10 @@
 		this.ast = ast;
 	}
 
+	public ASExpression getExpression() {
+		return ExpressionBuilder.build(ast.getFirstChild());
+	}
+	
 	public String getExpressionString() {
 		return ASTUtils.stringifyNode(ast.getFirstChild());
 	}
Index: src/main/java/uk/co/badgersinfoil/metaas/impl/AssignmentOperatorMap.java
===================================================================
--- src/main/java/uk/co/badgersinfoil/metaas/impl/AssignmentOperatorMap.java	(revision 0)
+++ src/main/java/uk/co/badgersinfoil/metaas/impl/AssignmentOperatorMap.java	(revision 0)
@@ -0,0 +1,51 @@
+package uk.co.badgersinfoil.metaas.impl;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.antlr.runtime.Token;
+import org.asdt.core.internal.antlr.AS3Parser;
+import uk.co.badgersinfoil.metaas.dom.ASAssignmentExpression;
+import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListToken;
+
+public class AssignmentOperatorMap {
+
+	private static final Map OPERATORS_BY_TYPE = new HashMap();
+	private static final Map TYPES_BY_OPERATOR = new HashMap();
+
+	private static void mapOp(int type, String text, ASAssignmentExpression.Op operator) {
+		OPERATORS_BY_TYPE.put(new Integer(type), operator);
+		TYPES_BY_OPERATOR.put(operator, new LinkedListToken(type, text));
+	}
+
+	static {
+		mapOp(AS3Parser.PLUS_ASSIGN, "+=", ASAssignmentExpression.Op.ADD_ASSIGN);
+		mapOp(AS3Parser.ASSIGN, "=", ASAssignmentExpression.Op.ASSIGN);
+		mapOp(AS3Parser.BAND_ASSIGN, "&=", ASAssignmentExpression.Op.BITAND_ASSIGN);
+		mapOp(AS3Parser.BOR_ASSIGN, "|=", ASAssignmentExpression.Op.BITOR_ASSIGN);
+		mapOp(AS3Parser.BXOR_ASSIGN, "^=", ASAssignmentExpression.Op.BITXOR_ASSIGN);
+		mapOp(AS3Parser.DIV_ASSIGN, "/=", ASAssignmentExpression.Op.DIV_ASSIGN);
+		mapOp(AS3Parser.MOD_ASSIGN, "%=", ASAssignmentExpression.Op.MOD_ASSIGN);
+		mapOp(AS3Parser.STAR_ASSIGN, "*=", ASAssignmentExpression.Op.MUL_ASSIGN);
+		mapOp(AS3Parser.SL_ASSIGN, "<<=", ASAssignmentExpression.Op.SL_ASSIGN);
+		mapOp(AS3Parser.SR_ASSIGN, ">>=", ASAssignmentExpression.Op.SR_ASSIGN);
+		mapOp(AS3Parser.BSR_ASSIGN, ">>=", ASAssignmentExpression.Op.SRU_ASSIGN);
+		mapOp(AS3Parser.MINUS_ASSIGN, "-=", ASAssignmentExpression.Op.SUB_ASSIGN);
+	}
+
+	public static ASAssignmentExpression.Op opFromType(int type) {
+		ASAssignmentExpression.Op op = (ASAssignmentExpression.Op)OPERATORS_BY_TYPE.get(new Integer(type));
+		if (op == null) {
+			throw new IllegalArgumentException("No operator for token-type "+ASTUtils.tokenName(type));
+		}
+		return op;
+	}
+
+	public static void initialiseFromOp(ASAssignmentExpression.Op operator, Token tok) {
+		LinkedListToken type = (LinkedListToken)TYPES_BY_OPERATOR.get(operator);
+		if (type == null) {
+			throw new IllegalArgumentException("No operator for Op "+operator);
+		}
+		tok.setType(type.getType());
+		tok.setText(type.getText());
+	}
+}
\ No newline at end of file