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From: Roger L Costello <costello@mitre.org>
Newsgroups: comp.compilers
Subject: Flex is the most powerful lexical analysis language in the world. True or False?
Date: Wed, 4 May 2022 11:22:34 +0000
Organization: Compilers Central
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Hi Folks,

1. A lexical analysis language that exclusively provides regular expressions
for scanning input can only process regular languages.

(a) True
(b) False

2. Flex provides, in addition to regular expressions, states and a pushdown
stack. This greatly expands the set of languages that can be processed.

(a) True
(b) False

3. Because Flex provides states and a pushdown stack, Flex lexers can process
context-free languages.

(a) True
(b) False

4. No other lexical analysis language provides states and a pushdown stack.

(a) True
(b) False

5. Flex is the most powerful lexical analysis language in the world.

(a) True
(b) False

/Roger
[I think that you could easily graft a state stack into any lexer that has start states.
Also, tools like Antlr combine the lexer and parser generators, so they're at least as
powerful as flex. -John]