In this article I’ll show you how you can create the abstract syntax tree (AST) of an input stream while parsing it. A parser usually reads various tokens from its input by using a lexer as a helper coroutine and tries to match various grammar rules that specify the syntax of a language (the source language).
Tag Archive: parser
In this article I’ll present to you some common conflicts that usually occur in Bison grammars and ways of resolving these. At first, conflicts in Bison context are situations where a sequence of input can be parsed in multiple ways according to the specified BNF grammar rules.
This project refers to the development of the procedural programming language YAFL (Yet Another Free Language) as well as its interpreter. The programming language YAFL is a tool for teaching the basic principles of procedural programming to secondary school students and beginners in general.
The following program creates the syntax tree of a mathematical expression in prefix notation. For simplicity, we assume that the terms of the expression are individual characters (digits). Each time the recursive function parse() is called, a new node is created, whose value is the next character of the expression. If the value is a term (digit), we return the new node. However, if it is an operator, we set the left and right pointers to point the tree made (recursively) for the two operands.
Efstathios Chatzikyriakidis 