Hi. I'm trying to build an automata from a regular expression, using

the algorithm given in "Regular Expressions into Finita Automata" from

Anne Bruggermann-Klein.

Somewhere in the paper says:

"Let n be the size of E. We begin by converting E into a syntax tree.

The external nodes are labeled with <empty> <epsilon> and the

occurrences of symbols, and the internal nodes are labeled with one of

the operatores +,., or *. Since the regular expressions are generated

by an LL(1) grammar, this can be donde in time O(n). Each node of the

syntax tree corresponds to a subexpression Ev of E".

There's someting here I cannot understand: if you construct and LL(1)

grammar for the language of regular expressions, you don't get a

syntax tree like the one mentioned there, but another where (as

symbols like * or + are part of the strings) all symbols of the

expression are leaves. As the algorith work assuming the

tree-structure mentioned, I cannot go on. Am I missing something? Do I

have to convert from one form to another?

thanks for your help

gmonce

1. representing functions with arguments in an abstract syntax tree

3. ** ML-Yacc abstract syntax tree source position

4. [ANN] S-Expression Syntax Trees for C!

5. Syntax tree collecting macro ?

6. Building the syntax tree for the interpreter pattern

7. Data structures for syntax trees

8. Design Pattern for creating Abstract Syntax Tree??

9. Abstract Syntax Trees, Semantic Analysis

10. editor for direct editing of the syntax tree: possible?

11. Storing Data Structures of Stored Procedures in Syntax Tree

12. Bison: reentrant C++ abstract-syntax-tree parser

13. introduction to BNF, concrete syntax trees

14. representing functions with arguments in an abstract syntax tree

15. Syntax tree generation under different parsing techniques

1 post • Page:**1** of **1**