drewc / smug Goto Github PK

Super Monadic Über Go-into : parser combinators for Common Lisp

License: MIT License

Common Lisp 100.00%

smug's Introduction

SMUG : Super Monadic Über Go-into

SMUG is a library for parsing text, based on monadic parser combinators. Using a simple technique from the functional programming camp, SMUG makes it simple to create quick extensible recursive descent parsers without funky syntax or impenetrable macrology.

Features

parsers are first class values written in basic lisp
non-deterministic infinite look-ahead
easy to learn, easy to use
extensible input protocol : parse strings, streams, lists etc
in-depth tutorial : no previous experience required.

Download and Install

cd ~/quicklisp/local-projects
git clone https://github.com/drewc/smug.git

(ql:quickload :smug)

Documentation

See doc/smug.org

Support

https://github.com/drewc/smug/issues or mailto:[email protected]

Licence

The MIT License (MIT)

see LICENSE

smug's People

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krzysz00 jasom jkordani erick-ikki icosahedron lczch fiddlerwoaroof blasut riptidemyth cl-kuthirgal snan nicholasbhubbard evalwhen

smug's Issues

Metadata for Quicklisp

Please consider adding :description, :author and :license information to your ASDF system. This will greatly help Quicklisp users and make it easier for them to report bugs.

More information:

http://blog.quicklisp.org/2015/05/looking-for-more-metadata.html
https://www.quicklisp.org

Evaluation aborted as calling CLOSURE by providing the input of the predicate in .satisfies.

As going through the section ".SATISFIES : the parser predicate" in the tutorial. Then I have the input of the predicate digit-char-p to make the CLOSURE for .satisfies , see the below.

(setq ss (.bind (.item) 
        (lambda (x) 
          (if (apply #'digit-char-p x)
              (.identity x)
              (.fail)))))

Then call (funcall ss "1 and") ,then it evaluation aborted. See the following backtrace

  0: ((LAMBDA (X)) #\1)
  1: ((LAMBDA (INPUT) :IN .BIND) "1 and")
  2: (SB-INT:SIMPLE-EVAL-IN-LEXENV (FUNCALL SS "1 and") #<NULL-LEXENV>)
  3: (EVAL (FUNCALL SS "1 and"))

License?

I looked around but couldn't find a license for this. What (if any) license is it released under?

at-least is broken when :limit is not pased

When :limit is not passed, it still tries to decrement it, causing an error for (1- nil).
Changling line 199 of smug.lisp to this fixes the problem.
(xs (at-least (1- n) parser :limit (and limit (1- limit)))))

input-rest broken when input is "base-string"

This is an issue on ECL which makes strings base-string unless they contain non base-chars; for example (type-of "") => (SIMPLE-ARRAY BASE-CHAR (0))

The fix is fairly easy; you can either specialize input-rest for base-string, or add this to the beginning of input-rest for cl:string:

(when (not (equal (array-element-type input)
              (upgraded-array-element-type 'character)))
      (setf input
        (make-array (length input) :element-type 'character
            :initial-contents input)))

Finding position of parse fails

Hi!

This is a cool project, I've enjoyed playing with it.

I was trying it out as an alternative for a parser I'm putting together for a project of my own. I need the ability to identify the line number and context of a parser failure. I don't see any way to do that off hand with Smug. Is that possible?

Thanks!