X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=code%2Flambda.js;h=0eea4c9275befaeafb673d3696e8a813dfbfce1f;hp=609cce03f850a15d68c91cc4cbf00716d214512b;hb=c675006fcaa7ef7f096b0cf8e73e28ecb79aa1a9;hpb=bd9306cd8ed960db37717c40573e8230a9dd65bf diff --git a/code/lambda.js b/code/lambda.js index 609cce03..0eea4c92 100644 --- a/code/lambda.js +++ b/code/lambda.js @@ -207,11 +207,14 @@ function Lambda_var(variable) { var res = left, x; while (stack.length) { x = stack.shift(); - res = new Lambda_app(res, x.eval_loop([], eta)); + // res = new Lambda_app(res, x.eval_loop([], eta)); + res = new Lambda_app(res, reduce(x, eta, false)); } return res; } - return unwind(this, stack); + // return unwind(this, stack); + // trampoline to, args + return [null, unwind(this, stack)]; }; this.eval_cbv = function (aggressive) { return this; @@ -261,7 +264,9 @@ function Lambda_app(left, right) { this.eval_loop = function (stack, eta) { var new_stack = stack.slice(0); new_stack.unshift(this.right); - return this.left.eval_loop(new_stack, eta); + // return this.left.eval_loop(new_stack, eta); + // trampoline to, args + return [this.left, new_stack, eta]; }; this.eval_cbv = function (aggressive) { var left = this.left.eval_cbv(aggressive); @@ -355,16 +360,19 @@ function Lambda_lam(variable, body) { }; this.eval_loop = function (stack, eta) { if (stack.length === 0) { - var term = new Lambda_lam(this.bound, this.body.eval_loop([], eta)); - if (eta) { - return term.check_eta(); - } else { - return term; - } + // var term = new Lambda_lam(this.bound, this.body.eval_loop([], eta)); + var term = new Lambda_lam(this.bound, reduce(this.body, eta, false)); + if (eta) { + return [null, term.check_eta()]; + } else { + return [null, term]; + } } else { var x = stack[0]; var xs = stack.slice(1); - return subst(this.bound, x, this.body).eval_loop(xs, eta); + // return subst(this.bound, x, this.body).eval_loop(xs, eta); + // trampoline to, args + return [subst(this.bound, x, this.body), xs, eta]; } }; this.eval_cbv = function (aggressive) { @@ -414,7 +422,13 @@ function reduce(expr, eta, cbv) { if (cbv) { return expr.eval_cbv(cbv > 1); } else { - return expr.eval_loop([], eta); + // return expr.eval_loop([], eta); + var to_eval = expr, res = [[], eta]; + while (to_eval !== null) { + res = to_eval.eval_loop.apply(to_eval, res); + to_eval = res.shift(); + } + return res[0]; } } @@ -436,42 +450,11 @@ try { } } catch (e) {} -/* -let true = K in -let false = \x y. y in -let and = \l r. l r false in -let or = \l r. l true r in -let pair = \u v f. f u v in -let triple = \u v w f. f u v w in -let succ = \n s z. s (n s z) in -let pred = \n s z. n (\u v. v (u s)) (K z) I in -let ifzero = \n. n (\u v. v (u succ)) (K 0) (\n withp whenz. withp n) in -let add = \m n. n succ m in -let mul = \m n. n (\z. add m z) 0 in -let mul = \m n s. m (n s) in -let sub = (\mzero msucc mtail. \m n. n mtail (m msucc mzero) true) (pair 0 I) (\d. d (\a b. pair (succ a) (K d))) (\d. d false d) in -let min = \m n. sub m (sub m n) in -let max = \m n. add n (sub m n) in -let lt = (\mzero msucc mtail. \n m. n mtail (m msucc mzero) true (\x. true) false) (pair 0 I) (\d. d (\a b. pair (succ a) (K d))) (\d. d false d) in -let leq = (\mzero msucc mtail. \m n. n mtail (m msucc mzero) true (\x. false) true) (pair 0 I) (\d. d (\a b. pair (succ a) (K d))) (\d. d false d) in -let eq = (\mzero msucc mtail. \m n. n mtail (m msucc mzero) true (\x. false) true) (pair 0 (K (pair 1 I))) (\d. d (\a b. pair (succ a) (K d))) (\d. d false d) in -let divmod = (\mzero msucc mtail. \n divisor. - (\dhead. n (mtail dhead) (\sel. dhead (sel 0 0))) - (divisor msucc mzero (\a b c. c x)) - (\d m a b c. pair d m) ) - (triple succ (K 0) I) - (\d. triple I succ (K d)) - (\dhead d. d (\dz mz df mf drest sel. drest dhead (sel (df dz) (mf mz)))) in -let div = \n d. divmod n d true in -let mod = \n d. divmod n d false in -let Y = \f. (\y. f(y y)) (\y. f(y y)) in -let Z = (\u f. f(u u f)) (\u f. f(u u f)) in -let fact = \y. y (\f n. ifzero n (\p. mul n (f p)) 1) in -fact Z 3 -*/ +// Chris's original + // // Basic data structure, essentially a LISP/Scheme-like cons // // pre-terminal nodes are expected to be of the form new cons(null, "string") // function cons(car, cdr) {