Design and Implementation of the Symbol Table for Object-Oriented Programming Language

Abstract

The symbol table used in the existing compiler stores one symbol information into a plurality of sub tables, and the abstract syntax tree necessary for generating symbols has a binary tree structure composed of a single data structure node. This structure increases the source code complexity of modules that generate symbols and modules that reference symbol tables, and when designing a compiler for a new language, it is necessary to newly design an abstract syntax tree and a symbol table structure considering the characteristics of the language. In this paper, we apply the object-oriented principle and visitor pattern to improve the abstract syntax tree structure and design and implement the symbol table for the object oriented language. The design of AST (abstract syntax trees) with object-oriented principles and Visitor patterns reduces the time and cost of redesign because it makes it easy to add features of the language without the need to redesign the AST (abstract syntax tree) for the new object-oriented language. In addition, it is easy to create a symbol through the Visitor pattern. Symbol tables using the open-close principle and the dependency inversion principle can improve the code reusability of the source code that creates and refer to the table and improve the readability of the code.