Expand typed SQL DSL

internal/lang/parser.go

@@ -698,6 +698,17 @@ func (p *parser) parseStmt() (Stmt, error) {
 		if err != nil {
 			return nil, err
 		}
+		if p.match(tokenAssign) {
+			target, ok := expr.(SelectorExpr)
+			if !ok {
+				return nil, fmt.Errorf("assignment target must be a variable or field selector")
+			}
+			value, err := p.parseExpr(0)
+			if err != nil {
+				return nil, err
+			}
+			return FieldAssignStmt{Target: target, Value: value}, nil
+		}
 		return ExprStmt{Value: expr}, nil
 	}
 }