1 files changed, 86 insertions, 1 deletions

diff --git a/src/minijava/symboltable/MExpression.java b/src/minijava/symboltable/MExpression.java
index 17d6db8..4cf4724 100644
--- a/src/minijava/symboltable/MExpression.java
+++ b/src/minijava/symboltable/MExpression.java
@@ -1,5 +1,8 @@
 package minijava.symboltable;
 
+import minijava.syntaxtree.Identifier;
+import minijava.typecheck.PrintError;
+
 public class MExpression extends MType {
 	public enum Operator {
 		And, Smaller, Plus, Minus, Times, ArrayLookup,
@@ -15,12 +18,90 @@ public class MExpression extends MType {
 	// Expression value (for primary expression)
 	public String e_val;
 	
-	public MExpression(Operator op) {
+	public MExpression(int line, int column, Operator op) {
+		super(line, column);
 		e_op = op;
 		e_exp = new MPrimaryExpr();
 		e_list = new MExpressionList();
 	}
 	
+	public String exprType(MMethod m) {
+		switch (e_op) {
+		case And:
+			if (first.exprType(m)==MIdentifier.boolType
+			&& second.exprType(m)==MIdentifier.boolType) {
+				return MIdentifier.boolType;
+			} else {
+				PrintError.print(line, column, "Type mismatch");
+				return null;
+			}
+		case ArrayLen:
+			if (first.exprType(m)==MIdentifier.arrType) {
+				return MIdentifier.intType;
+			} else {
+				PrintError.print(line, column, "Type mismatch");
+				return null;
+			}
+		case ArrayLookup:
+			if (first.exprType(m)==MIdentifier.arrType
+			&& second.exprType(m)==MIdentifier.intType) {
+				return MIdentifier.intType;
+			} else {
+				PrintError.print(line, column, "Type mismatch");
+				return null;
+			}
+		case Smaller:
+			if (first.exprType(m)==MIdentifier.intType
+			&& second.exprType(m)==MIdentifier.intType) {
+				return MIdentifier.boolType;
+			} else {
+				PrintError.print(line, column, "Type mismatch");
+				return null;
+			}
+		case Plus:
+		case Minus:
+		case Times:
+			if (first.exprType(m)==MIdentifier.intType
+			&& second.exprType(m)==MIdentifier.intType) {
+				return MIdentifier.intType;
+			} else {
+				PrintError.print(line, column, "Type mismatch");
+				return null;
+			}
+		case MsgSend:
+			// expr.id(expr*)
+			String c_type = first.exprType(m);
+			MClass m_class = m.method_class.all_classes.findClassByName(c_type);
+			if (m_class==null) {
+				PrintError.print(line, column, "no class found in a message send expression");
+				return null;
+			}
+			int idx = m_class.methods.findMethod(e_id.name);
+			if (idx==-1) {
+				PrintError.print(line, column, "method " + e_id.name + " not found");
+				return null;
+			}
+			MMethod m_method = m_class.methods.methods.elementAt(idx);
+			if (e_list.size()!=m_method.paramList.size()) {
+				PrintError.print(line, column, "Method param size mismatch!");
+				return null;
+			}
+			for (int i=0; i<e_list.size(); i++) {
+				String t1 = e_list.e_list.elementAt(i).exprType(m);
+				String t2 = m_method.paramList.varlist.elementAt(i).typename;
+				if (!t1.equals(t2)) {
+					PrintError.print(line, column, "Method param type mismatch!");
+					return null;
+				}
+			}
+			return m_method.ret_type_name;
+		case Primary:
+			return e_exp.primExprType(m);
+		default:
+			return null;
+		}
+	}
+	
 	public void printExpr(int spaces) {
 		System.err.print(OutputFormat.spaces(spaces));
 		
@@ -54,6 +135,10 @@ public class MExpression extends MType {
 			second.printExpr(0);
 			break;
 		case ArrayLookup:
+			first.printExpr(0);
+			System.err.print("[");
+			second.printExpr(0);
+			System.err.print("]");
 		case ArrayLen:
 		case MsgSend:
 		}