Pest
Languages and libraries
parser generator
SHOW HN2017
How HN took it
6 positive, 3 neutral or asking, 0 mixed, 5 critical, out of 14 comments about the project. Thread score -0.07.
Docs: 1 for, 2 againstPerformance: 1 for, 1 againstIdea: 1 for, 1 againstDesign: 0 for, 1 againstExecution: 1 for, 0 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Speed is good and the DSL feels familiar
From 1 comment
Been using this for a couple weeks now and dig it. The DSL feels familiar and the speed is yummy. I'd been using LALRPOP for some months; I dig it too, but just couldn't get the…
turboladen on HN
Objections
Title suggested it was a Rust AST parser, not a parser generator
From 3 comments
Shouldn't the title better by "Pest - Fast, modern parser _in_ Rust"? The current title made me think that this would be a Rust AST parser, similar to syntex.
hobofan on HNYes this is no doubt the current implication. I was expecting something like racer.
grimgrin on HNExactly what I came into this thread expecting. Was curious why when it looks like there's already great IDE support for Rust with existing tools.
reificator on HN
Creative operator overloading in the grammar syntax is hard to read
From 1 comment
This is a neat project! I might take a look at this if/when I get started on my dream language. :p One constructive criticism, which may be only an unpopular opinion, but I find…
weberc2 on HN
Benchmark comparison with nom seemed unfair
From 1 comment
I'm a bit confused by the benchmark. I looked through the benchmark code and, without really understanding what I'm looking at, the result of the nom parser looks much closer to…
jorams on HN
Requests
Clearer title stating it is a parser generator
From 2 comments
Shouldn't the title better by "Pest - Fast, modern parser _in_ Rust"? The current title made me think that this would be a Rust AST parser, similar to syntex.
hobofan on HNThe confusion here is because Pest is not, in fact, a parser. It's a parser generator: you can use it to generate parsers (maybe even a parser for Rust), but it is not in itself…
z1mm32m4n on HN
Questions
What type of parser does it produce?
From 1 comment
What type of parser does this produce?
DC-3 on HN
Does it handle Unicode character families well?
From 2 comments
I remember playing with PEGjs back in the day, making a toy implementation of JS in JS. It had terrible Unicode support though. To build a token out of valid Unicode…
OtterCoder on HNThe difficulty wasn't in the engine. JS itself is just as good with accepting Unicode characters as Rust, both in code and strings. The problem was with the PEG implementation.…
OtterCoder on HN
Alternatives named
LALRPOP
From 1 comment
Been using this for a couple weeks now and dig it. The DSL feels familiar and the speed is yummy. I'd been using LALRPOP for some months; I dig it too, but just couldn't get the…
turboladen on HN
nom
From 1 comment
I'm a bit confused by the benchmark. I looked through the benchmark code and, without really understanding what I'm looking at, the result of the nom parser looks much closer to…
jorams on HN
syn
From 1 comment
There's actually a parser for rust called syn, and it's very useful for procedural macros, as the current API exposes a stream of tokens, not a full AST.
dikaiosune on HN
GNU Bison and Yacc
From 1 comment
"Parsing expression grammars (PEGs) are an alternative to context free grammars for formally specifying syntax" [1] Basically, you have tools for context free grammars such as…
jmcomets on HN
PEGjs
From 1 comment
I remember playing with PEGjs back in the day, making a toy implementation of JS in JS. It had terrible Unicode support though. To build a token out of valid Unicode…
OtterCoder on HN