Change assignment into expressions

ast/ast.go

@@ -389,29 +389,27 @@ func (we *WhileExpression) String() string {
 	return out.String()
 }
 
-// AssignmentStatement the `=` statement represents the AST node that rebinds
-// an expression to an identifier (assigning a new value).
-type AssignmentStatement struct {
+// AssignmentExpression represents an assignment expression of the form:
+// x = 1 or xs[1] = 2
+type AssignmentExpression struct {
 	Token token.Token // the token.ASSIGN token
-	Name  *Identifier
+	Left  Expression
 	Value Expression
 }
 
-func (as AssignmentStatement) TokenLiteral() string {
+func (as AssignmentExpression) TokenLiteral() string {
 	return as.Token.Literal
 }
-func (as AssignmentStatement) String() string {
+func (as AssignmentExpression) String() string {
 	var out bytes.Buffer
 
-	out.WriteString(as.Name.String())
-	out.WriteString(as.TokenLiteral() + " ")
+	out.WriteString(as.Left.String())
+	out.WriteString(as.TokenLiteral())
 	out.WriteString(as.Value.String())
 
-	out.WriteString(";")
-
 	return out.String()
 }
-func (as AssignmentStatement) statementNode() {}
+func (as AssignmentExpression) expressionNode() {}
 
 // Comment a comment
 type Comment struct {