3 ms·

How to write a parser in Go

85 points by beliu 8y ago

lloeki 8y ago
tl;dr: write a parser using goyacc, a yacc port that therefore has some impedance mismatch with Go. (go)yacc is LALR(1) I've been using PEG/Packrat implementations providing a more "native" experience to great effect lately, notably ruby's treetop and golang's pointlander/peg. https://github.com/cjheath/treetop https://github.com/cjheath/treetop https://github.com/pointlander/peg https://github.com/pointlander/peg
rijoja 8y ago
This project gives me I have a solution please give me a problem feeling. I remember looking into yacc a while ago, for some reason but I can't really remember doing why. Might've been for a configuration type of deal, but nowadays I just use json for that because it intersects other areas of the code and therefore saves time.
jcelerier 8y ago
yuck, I'd take boost.spirit every day over this
- naikrovek 8y ago
  good for you. Maybe try saying something positive next time, even if you have to fabricate it. Or just don't comment.
gameswithgo 8y ago
Another very good take on this topic that really was the first thing that made it all click for me: https://www.youtube.com/watch?v=HxaD_trXwRE https://www.youtube.com/watch?v=HxaD_trXwRE
kalekold 8y ago
Or you can read this: https://interpreterbook.com/ https://interpreterbook.com/
- stevekemp 8y ago
  That's a good read. I extended my version of monkey to add a ton of new features and found it easy: https://github.com/skx/monkey/ https://github.com/skx/monkey/ Over the past two days I also switched a toy-project for deploying software via SSH/SCP to using a lexer/parser, rather than parsing via regular expressions and string-splits. I guess that means that I learned something: https://github.com/skx/deployr https://github.com/skx/deployr
weberc2 8y ago
I played with this last year but couldn’t wrap my head around it. I don’t recall if it was poorly documented at the time or if it couldn’t handle something I was trying to do or if I was just depressed by the generated code quality, but I eventually gave up and tried rolling my own parser by hand. It was the first time I’d done such a thing and I didn’t really understand patterns for writing parsers so I eventually gave up there too. I’m really excited to read Thorsten Ball’s “How to write an Interpreter in Go” book which walks the reader through writing a parser by hand (his blog post about book-writing tools was on the front page here—or maybe it was /r/programming?—yesterday, incidentally).

85 points by beliu 8y ago

tl;dr: write a parser using goyacc, a yacc port that therefore has some impedance mismatch with Go. (go)yacc is LALR(1) I've been using PEG/Packrat implementations providing a more "native" experience to great effect lately, notably ruby's treetop and golang's pointlander/peg. https://github.com/cjheath/treetop https://github.com/cjheath/treetop https://github.com/pointlander/peg https://github.com/pointlander/peg

rijoja 8y ago

This project gives me I have a solution please give me a problem feeling. I remember looking into yacc a while ago, for some reason but I can't really remember doing why. Might've been for a configuration type of deal, but nowadays I just use json for that because it intersects other areas of the code and therefore saves time.

jcelerier 8y ago

yuck, I'd take boost.spirit every day over this

naikrovek 8y ago
good for you. Maybe try saying something positive next time, even if you have to fabricate it. Or just don't comment.

gameswithgo 8y ago

Another very good take on this topic that really was the first thing that made it all click for me: https://www.youtube.com/watch?v=HxaD_trXwRE https://www.youtube.com/watch?v=HxaD_trXwRE

kalekold 8y ago

Or you can read this: https://interpreterbook.com/ https://interpreterbook.com/

stevekemp 8y ago
That's a good read. I extended my version of monkey to add a ton of new features and found it easy: https://github.com/skx/monkey/ https://github.com/skx/monkey/ Over the past two days I also switched a toy-project for deploying software via SSH/SCP to using a lexer/parser, rather than parsing via regular expressions and string-splits. I guess that means that I learned something: https://github.com/skx/deployr https://github.com/skx/deployr

weberc2 8y ago

I played with this last year but couldn’t wrap my head around it. I don’t recall if it was poorly documented at the time or if it couldn’t handle something I was trying to do or if I was just depressed by the generated code quality, but I eventually gave up and tried rolling my own parser by hand. It was the first time I’d done such a thing and I didn’t really understand patterns for writing parsers so I eventually gave up there too. I’m really excited to read Thorsten Ball’s “How to write an Interpreter in Go” book which walks the reader through writing a parser by hand (his blog post about book-writing tools was on the front page here—or maybe it was /r/programming?—yesterday, incidentally).