Concept explainers
Explanation of Solution
Extended Backus-Naur Form (EBNF):
BNF is a natural notation for describing syntax described by John Backus and Peter Naur. By extending it, we had EBNF which only enhances the readability and writability of BNF.
The recursive descent parser works on the following EBNF for the arithmetic expressions:
{(+|-)}
{(*|/)}
id|int_constant|()
We know that, the following tokens are returned by the lexical analyzer for the lexemes:
Token | Lexeme |
11 | Identifier |
21 | + Operator |
23 | * Operator |
25 | ( |
26 | ) |
In the table the left column having the heading token refers to the token codes to the different types of the categories like:-
a) 11 = identifier
b) 21 =ADD operator
c) 23 = MULTIPLY operator
d) 25 = left brace lexeme
The example given in the problem is
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Concepts Of Programming Languages
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