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Re-arranging for Mocha.

This commit is contained in:
Elf M. Sternberg 2015-06-17 12:34:31 -07:00
parent 647dfbbc14
commit f17e74207e
6 changed files with 98 additions and 154 deletions
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5
.gitignore vendored
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@ -7,3 +7,8 @@ package.yml
node_modules/*
tmp/
test/
bin/_mocha
bin/mocha
bin/coffee
bin/cake

0
chapter1/lisp_ch1.coffee → chapter1/interpreter.coffee
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206
chapter3/interpreter.coffee
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@ -1,41 +1,18 @@
{listToString, listToVector, pairp, cons, car, cdr, caar, cddr, cdar, cadr, caadr, cadar, caddr, nilp, nil, setcdr, metacadr} = require "cons-lists/lists"
readline = require "readline"
{inspect} = require "util"
print = require "../chapter1/print"
cadddr = metacadr('cadddr')
{inspect} = require "util"
cpsdecorate = (fn) ->
(args...) ->
callback = args[args.length - 1]
tocall = args[0 ... (args.length-1)]
callback fn.apply(@, args)
ntype = (node) -> car node
nvalu = (node) -> cadr node
[listToString, listToVector, pairp, cons, car, cdr,
caar, cddr, cdar, cadr, caadr, cadar, caddr, nilp,
nil, setcdr, metacadr, ntype, nvalu] = [listToString,
listToVector, pairp, cons, car, cdr, caar, cddr,
cdar, cadr, caadr, cadar, caddr, nilp, nil, setcdr,
metacadr, ntype, nvalu].map(cpsdecorate)
# Debugging tool.
env_init = nil
env_global = env_init
# Takes a name and a value and pushes those onto the global environment.
ntype = (node) -> car node
nvalu = (node) -> cadr node
definitial = (name, value = nil, callback) ->
cons name, value, (ls) ->
cons ls, env_global, callback
# Takes a name, a native function, and the expected arity of that
# function, and returns the global environment with new a (native)
# function perpared to unpack any (interpreter) variable pairs and
# apply the (native) function with them.
definitial = (name, value = nil) ->
env_global = (cons (cons name, value), env_global)
name
defprimitive = (name, nativ, arity) ->
definitial name, ((args) ->
@ -55,16 +32,12 @@ definitial "bar"
definitial "fib"
definitial "fact"
# Wraps a native predicate in function to ensure the interpreter's
# notion of falsity is preserved.
defpredicate = (name, nativ, arity) ->
defprimitive name, ((a, b) -> if nativ.call(null, a, b) then true else the_false_value), arity
defprimitive "cons", cons, 2
defprimitive "car", car, 2
defprimitive "set-cdr!", setcdr, 2
defprimitive "log", ((a) -> console.log a), 1
defprimitive "+", ((a, b) -> a + b), 2
defprimitive "*", ((a, b) -> a * b), 2
defprimitive "-", ((a, b) -> a - b), 2
@ -72,10 +45,6 @@ defprimitive "/", ((a, b) -> a / b), 2
defpredicate "lt", ((a, b) -> a < b), 2
defpredicate "eq?", ((a, b) -> a == b), 2
# Takes an environment, a list of names and a list of values, and for
# each name and value pair pushes that pair onto the list, adding them
# to the environment.
extend = (env, variables, values) ->
if (pairp variables)
if (pairp values)
@ -91,66 +60,51 @@ extend = (env, variables, values) ->
else
nil
# Takes a list of variable names, a function body, and an environment
# at the time of evaluation, and returns:
# a (native) function that takes a list of values, applies them to the
# environment, and evaluates the body, returning the resulting value.
make_function = (variables, body, env, continuation) ->
continuation (values, cb) -> eprogn body, (extend env, variables, values), cb
make_function = (variables, body, env) ->
(values) -> eprogn body, (extend env, variables, values)
# Evaluates a (native) function with of one arg with the arg provided.
# Invoke runs the functions created by make_function, and is unrelated
# to the native functions of defprimitive()
invoke = (fn, arg) -> (fn arg)
invoke = (fn, args, cb) ->
fn args, cb
# Takes a list of nodes and calls evaluate on each one, returning the
# last one as the value of the total expression. In this example, we
# are hard-coding what ought to be a macro, namely the threading macro
# often named "->"
# are hard-coding what ought to be a macro, namely the threading
# macros, "->"
eprogn = (exps, env, callback) ->
eprogn = (exps, env, cb) ->
if (pairp exps)
if pairp (cdr exps)
evaluate (car exps), env, (c) ->
eprogn (cdr exps), env, callback
evaluate (car exps), env, (next) ->
eprogn (cdr exps), env, cb
else
evaluate (car exps), env, callback
evaluate (car exps), env, cb
else
nil
cb nil
# Evaluates a list of expressions and returns a list of resolved
# values.
evlis = (exps, env, callback) ->
callback if (pairp exps)
if (pairp cdr exps)
evaluate (cons (evaluate (car exps), env), (evlis (cdr exps), env))
evlis = (exps, env, cb) ->
if (pairp exps)
evaluate (car exps), env, (stepv) ->
evlis (cdr exps), env, (next) ->
cb cons stepv, next
else
nil
cb(nil)
# Locates a named reference in the environment and returns its value.
lookup = (id, env, callback) ->
callback if (pairp env)
lookup = (id, env, continuation) ->
if (pairp env)
if (caar env) == id
cdar env
continuation (cdar env)
else
lookup id, (cdr env)
lookup id, (cdr env), continuation
else
nil
# Locates a named reference in the environment and replaces its value
# with a new value.
continuation nil
update = (id, env, value, callback) ->
callback if (pairp env)
if (pairp env)
if (caar env) == id
setcdr value, (car env)
value
callback value
else
update id, (cdr env), value
update id, (cdr env), value, callback
else
nil
@ -158,70 +112,52 @@ update = (id, env, value, callback ) ->
# interpreter core. I can't help but think that this design precludes
# pluggable interpreter core.
# Yeah, for the CPS edition, this is WAY cheating:
astSymbolsToLispSymbols = (node, callback) ->
astSymbolsToLispSymbols = (node) ->
return nil if nilp node
throw "Not a list of variable names" if not (ntype(node) is 'list')
handler = (node) ->
return nil if nilp node
cons (nvalu car node), (handler cdr node)
callback handler(nvalu node)
handler(nvalu node)
# Takes an AST node and evaluates it and its contents, returning the
# final value of the calculation. A node may be ("list" (... contents
# ...)) or ("number" 42) or ("symbol" x), etc.
# Takes an AST node and evaluates it and its contents. A node may be
# ("list" (... contents ...)) or ("number" 42) or ("symbol" x), etc.
cadddr = metacadr('cadddr')
ceq = (l, r, thencallback, elsecallback) ->
(if l is r then thencallback else elsecallback)()
cin = (l, r, thencallback, elsecallback) ->
(if l in r then thencallback else elsecallback)()
cswitch = (key, ops, callback) ->
return ops[key](callback) if key of ops
return ops['_default'](callback) if '_default' of ops
throw new Error("Can't handle invocation of #{key}")
cpsevaluate = (exp, env, callback) ->
cdr exp, (envexp) ->
evlis envexp, env, (newenv) ->
car exp, (fnhandle) ->
evaluate fnhandle, env, callback
syntax =
"quote": (callback) -> cdr exp, callback
"if": (callback) ->
cadr exp, (e) ->
evaluate e, env, (c) ->
cif(c, the_false_value,
(-> cadddr exp, (e) -> evaluate e, env, callback),
(-> caddr exp, (e) -> evaluate e, env, callback))
"begin": (callback) -> cdr exp, ((e) -> eprogn e, env, callback)
"set!": (callback) -> cadr exp, (e) ->
nvalu e, (n) ->
caddr exp, (r) ->
evaluate r, env, (r2) ->
update n, env, r2, callback
"lambda": (callback) -> cddr expr, (body) ->
cadr exp, (astSymbols) ->
astSymbolsToLispSymbols astSymbols, (lispSymbols) ->
make_function lispSymbols, body, env, callback
"_default": (callback) -> cpsevaluate exp, env, callback
evaluate = (e, env, callback) ->
ntype e, (type) ->
nvalu e, (exp) ->
ceq type, "symbol", (-> lookup exp, env, callback), ->
cin type, ["number", "string", "boolean", "vector"], (-> callback exp), (->
ceq type, "list", (->
car exp, (head) ->
ntype head, (h) -> ceq h, "symbol", -> nvalu head, (hv) ->
cswitch hv, syntax, callback
), -> cpsevaluate exp, env, callback
), -> throw new Error("Can't handle a #{type}")
module.exports = (c) -> evaluate c, env_global
evaluate = (e, env, continuation) ->
[type, exp] = [(ntype e), (nvalu e)]
if type in ["number", "string", "boolean", "vector"]
return continuation exp
else if type == "symbol"
return lookup exp, env, continuation
else if type == "list"
head = car exp
if (ntype head) == 'symbol'
switch (nvalu head)
when "quote" then continuation cdr exp
when "if"
evaluate (cadr exp), env, (result) ->
unless result == the_false_value
evaluate (caddr exp), env, continuation
else
evaluate (cadddr exp), env, continuation
when "begin" then eprogn (cdr exp), env, continuation
when "set!" then evaluate (caddr exp), env, (value) ->
update (nvalu cadr exp), env, value, continuation
when "lambda"
make_function (astSymbolsToLispSymbols cadr exp), (cddr exp), env, continuation
else
console.log(cdr exp)
evlis (cdr exp), env, (args) ->
evaluate (car exp), env, (fn) ->
invoke fn, args, continuation
else
evlis (cdr exp), env, (args) ->
evaluate (car exp), env, (fn) ->
invoke fn, args, continuation
else
throw new Error("Can't handle a #{type}")
module.exports = (c, continuation) -> evaluate c, env_global, continuation

14
chapter3/test.coffee
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@ -1,14 +0,0 @@
lisp = require './interpreter.coffee'
{read, readForms} = require '../chapter1/reader'
{inspect} = require 'util'
ast = read("(log (begin (set! fact (lambda (x) (if (eq? x 0) 1 (* x (fact (- x 1)))))) (fact 5)))")
# ast = read("(begin (if (lt 4 2) (+ 4 1) (+ 2 1)))")
# ast = read("(begin (set! fact 4) fact)")
# ast = read("(begin ((lambda (t) (if (lt t 2) (+ 4 1) (+ 2 1))) 1))")
# ast = read("(begin (set! fact (lambda (x) (+ x x))) (fact 5))")
# ast = read("(begin (set! fact (lambda (x) (- x 4))) (fact 5))")
(lisp ast)

8
chapter1/test_chap1.coffee → test/test_chapter1.coffee
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@ -1,13 +1,15 @@
lisp = require './lisp_ch1'
{read, readForms} = require './reader'
{inspect} = require 'util'
ast = read("(begin (set! fact (lambda (x) (if (eq? x 0) 1 (* x (fact (- x 1)))))) (fact 5))")
# ast = read("(begin (if (lt 4 2) (+ 4 1) (+ 2 1)))")
# ast = read("(begin (set! fact (lambda (x) (if (eq? x 0) 1 (* x (fact (- x 1)))))) (fact 5))")
# ast = read("(begin (if (lt 4 5) (+ 4 1) (+ 2 1)))")
# ast = read("(begin (set! fact 4) fact)")
# ast = read("(begin ((lambda (t) (if (lt t 2) (+ 4 1) (+ 2 1))) 1))")
# ast = read("(begin (set! fact (lambda (x) (+ x x))) (fact 5))")
# ast = read("(begin (set! fact (lambda (x) (- x 4))) (fact 5))")
ast = read("(begin (set! fact (lambda (x) (- x 4))) (fact 5))")
# ast = read("(begin ((lambda () (+ 5 5))))")
console.log "Result:", (lisp ast)

15
test/test_chapter3.coffee Normal file
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@ -0,0 +1,15 @@
lisp = require './interpreter'
{read, readForms} = require '../chapter1/reader'
{inspect} = require 'util'
ast = read("(begin (set! fact (lambda (x) (if (eq? x 0) 1 (* x (fact (- x 1)))))) (fact 5))")
# ast = read("(begin (if (lt 4 5) (+ 4 1) (+ 2 1)))")
# ast = read("(begin (set! fact 4) fact)")
# ast = read("(begin ((lambda (t) (if (lt t 2) (+ 4 1) (+ 2 1))) 1))")
# ast = read("(begin (set! fact (lambda (x) (+ x x))) (fact 5))")
ast = read("(begin (set! fact (lambda (x) (- x 4))) (fact 5))")
# ast = read("(begin ((lambda () (+ 5 5))))")
lisp(ast, (r) -> console.log("Result:", r))