Compilers: Principles and Practice by Pearson

34 Compilers – Principles and Practice

2.2.2 Parser

The job of a parser is to identify the syntactic entities in the source code, build and output the parse tree.

For the example simple program, the syntactic units should be identified as:

program statements end

program

int a

let a

loop

;

;

:

var

=

10

assignment

llabel

print

a

a

print a

let a -

();

;

=

1

sssignment

goto

if

if a goto loop ;

We have opted for implementing the parser for simple as a recursive-descent parser (RDP). This

relatively simple parser implementation is possible if certain restrictions are put on the language and

its grammar, see Chapter 4 for details.

The grammar with which the parser is concerned ...