Elf M. Sternberg
73be7dee59
This adds many comments to the final interpreter, which hopefully helps me (and anyone else reading this) understand what's going on inside the 3G interpreter. [refactor] This last interpreter takes all the evaluate function's "syntax" objects and moves them into a lookup table. THis prefigures the idea of making even the syntax malleable and extensible by future code. I have to wonder if there's a place for making some core commands (the "holy 7" of McCarthy, for example) un-reassignable. Probably not. I can vaguely see an interest in wrapping even some core functions (car, cdr, cons) in contractual decorators. This concludes the base homework for chapter 3. I might get to the exercises someday. |
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| bin | ||
| chapter-lambda-1 | ||
| chapter1 | ||
| chapter3 | ||
| chapter3g | ||
| docs | ||
| extras | ||
| test | ||
| .gitignore | ||
| LICENSE | ||
| Makefile | ||
| README.md | ||
| coffeelint.json | ||
| package.json | ||
README.md
A Collection of Interpreters from Lisp In Small Pieces, written in Coffeescript
Purpose
I don't know Lisp, so I figured the correct place to start was to write my own interpreter. After buying five different textbooks (The Structure and Interpretation of Computer Programs, aka "The Wizard Book", Friedman's The Essentials of Programming Languages, Let over Lambda, On Lisp, and one more) I decided Christian Quinnec's Lisp In Small Pieces gave the clearest step-by-step introduction.
Since I didn't know Lisp, my task was to translate what Quiennec wrote in his book into a language I did know: Javascript. Well, Coffeescript, which is basically Javascript with a lot of the syntactical noise removed, which is why I liked it.
Usage
I don't know if you're going to get much out of it, but the reader (which I had to write by hand, seeing as I didn't have a native Lisp reader on hand in my Javascripty environment), and each interpreter has a fairly standard test case that demonstrates that each language does what it says it does: you can do math, set variables, name and create functions, and even do recursion.
Notes
chapter-lambda-1 is not from Lisp In Small Pieces. It is a primitive CPS interpreter built on top of the interpreter from LiSP Chapter 1, using techniques derived from a fairly facile reading of Lisperator's "Implement A Programming Language in Javascript." But it was fun.
LICENSE AND COPYRIGHT NOTICE: NO WARRANTY GRANTED OR IMPLIED
See the LICENSE file.