Best/fastest way to write a parser in c#

c# parsing abstract-syntax-tree
Nestor picture Nestor · Oct 1, 2009 · Viewed 7.7k times · Source

What is the best way to build a parser in c# to parse my own language? Ideally I'd like to provide a grammar, and get Abstract Syntax Trees as an output. Many thanks, Nestor

Answer

Pavel Minaev picture Pavel Minaev · Oct 1, 2009

I've had good experience with ANTLR v3. By far the biggest benefit is that it lets you write LL(*) parsers with infinite lookahead - these can be quite suboptimal, but the grammar can be written in the most straightforward and natural way with no need to refactor to work around parser limitations, and parser performance is often not a big deal (I hope you aren't writing a C++ compiler), especially in learning projects.

It also provides pretty good means of constructing meaningful ASTs without need to write any code - for every grammar production, you indicate the "crucial" token or sub-production, and that becomes a tree node. Or you can write a tree production.

Have a look at the following ANTLR grammars (listed here in order of increasing complexity) to get a gist of how it looks and feels

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