From b9a60e3fed7e49de55461c9787a040bc5939a2ea Mon Sep 17 00:00:00 2001 From: "Elf M. Sternberg" Date: Wed, 8 Jul 2015 14:45:59 -0700 Subject: [PATCH] [doc] Including blog entry for Chapter 3 As a chronic blogger, I've been updating my journey on my website at http://elfsternberg.com. This is where the original markdown files are kept. --- Makefile | 29 --------------------------- docs/20150607.md | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+), 29 deletions(-) delete mode 100644 Makefile create mode 100644 docs/20150607.md diff --git a/Makefile b/Makefile deleted file mode 100644 index 3ad704b..0000000 --- a/Makefile +++ /dev/null @@ -1,29 +0,0 @@ -.PHONY: test - -# docs: $(patsubst %.md,%.html,$(wildcard *.md)) - - - -all: $(targets) - -%.js: src/%.coffee - node_modules/.bin/mocha coffee -c -o . $< - -%.html: %.md header.html footer.html - cat header.html > $@ - pandoc $< >> $@ - cat footer.html >> $@ - -node_modules: package.json - mkdir -p node_modules - npm install - -test: clean node_modules - @JUNIT_REPORT_PATH=test-reports.xml JUNIT_REPORT_STACK=1 ./node_modules/.bin/mocha \ - --reporter mocha-jenkins-reporter --compilers coffee:coffee-script/register || true - -ltest: node_modules - @node_modules/.bin/mocha --compilers coffee:coffee-script/register - -clean: - rm -f report.xml test-reports.xml diff --git a/docs/20150607.md b/docs/20150607.md new file mode 100644 index 0000000..7488c09 --- /dev/null +++ b/docs/20150607.md @@ -0,0 +1,52 @@ +I've been working my way through a Lisp textbook, *Lisp In Small +Pieces*, by Christian Quinnec. It was originally written in French and +is not that well known among English-speaking Lisperati, not in +comparison to the Wizard book or Paul Graham's *On Lisp*, but what +caught my attention was how it really was in *small* pieces. Each +chapter ended with an interpreter described, sometimes in code, +sometimes in text; if you were smart enough, you could actually piece +the whole thing together and see how it worked. + +I decided to make things hard for myself. Since I'm *not* a Lisperati +(although I may well and truly be seduced by Hy), I decided to make +things hard for myself by writing the interpreter in Coffeescript. Most +Lisp books assume you have a Lisp handy, and Quinnec's examples are fine +and dandy on many variants of Scheme, but for a fun time I decided to +write it in something else. Raganwald claims Javascript "is a Lisp," +and if that's so it ought to be good enough to write a Lisp in it. + +I mean, it's obviously been done before. I tried once before but got +lost. *LiSP* does me the favor of keeping me on track. + +You can see all my sourcecode at Github: Lisp In +Small Pieces. + +Chapter 1 contains the base interpreter. It also contains a +hand-written Lisp reader, and refers to another project I have on +GitHub, cons-lists, which +is exactly what it sounds like, a singly-linked list implementation in +Javascript, using nested Javascript arrays as the base. The base +interpreter is very primitive-- you can't even create new variable names +in the global namespace! Although you can shadow them using lambdas, so +it's pretty much bog standard Lambda Calculus. + +Chapter "Lambda 1" contains a continuation-passing variant of the +interpreter from Chapter 1. It's basically a facile reading of +Lisperator's λ-language intepreter, with my own parser front-end and +some CPS style. It passes all the tests, but it's a distraction. + +Chapter 3 contains the same interpreter, only using the architecture +Quinnec describes in Chapter 3 of his book. + +Chapter 2 describes a number of different methodologies for binding, +scoping, and namespaces. The material is interesting but I didn't +pursue writing the various interpreters. I "got" what Quinnec was +saying, and if I'm ever interested in writing something with scoping +rules outside of the lexical scopes with which I'm familiar, I might +revisit the material. + +The next step will be to add functions to the Chapter 3 interpreter to +do the various continuation management games, like call/cc, throw/catch, +and so forth. Because *those*, I feel I need to understand.