On 24/08/2015 11:38, Bert Verhees wrote:
On 24-08-15 15:36, Thomas Beale wrote:
Antlr4 rule capabilities and particularly pattern matching is weaker
than yacc/lex (in some cases quite a lot weaker),
Of course, Yacc/lex can only be used to generate C-code. It's
functionality in pattern matching is limited to this.
nope - it can be used to generate anything (I use it to generate Eiffel
code). The point is it can only generate 1 language.
To do whatever you need to do, writing a compiler, translating
programming languages into another (transpiler), translating a query
language into another, processing data, JSON,. XML, CSV, to many
custom made targets, generated code accessible to choose for a
listener/visitor or tree pattern, and having scoped symbol tables,
that is where Antlr comes in.
actually - these are all output stages, and they are perfectly doable
with any yacc/lex compiler serialiser - which is what the ADL workbench
is, and what it does. Antlr des make a lot of this easier however.
Maybe the weakness is C-related? It is what one expects because the
nature of Yacc/lex.
yacc/lex grammars have nothing to do with C - they work the same way
with any language.
The weaknesses are mainly in the regex matching for string patterns -
Antlr doesn't do anything like full regex. Its stateful sub-grammar
handling needs a bit of work as well.
But I agree, it's probably the future, at least for a while.
- thomas
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