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author | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:25 -0800 |
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committer | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:25 -0800 |
commit | 8ffbc2df0fde83082610149d24e594c1cd879f4a (patch) | |
tree | a2be9aad5101c5e450ad141d15c514bc9c2a2963 /break.scm | |
download | slib-8ffbc2df0fde83082610149d24e594c1cd879f4a.tar.gz slib-8ffbc2df0fde83082610149d24e594c1cd879f4a.zip |
Import Upstream version 2a6upstream/2a6
Diffstat (limited to 'break.scm')
-rw-r--r-- | break.scm | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/break.scm b/break.scm new file mode 100644 index 0000000..e6ba634 --- /dev/null +++ b/break.scm @@ -0,0 +1,151 @@ +;;;; "break.scm" Breakpoints for debugging in Scheme. +;;; Copyright (C) 1991, 1992, 1993, 1995 Aubrey Jaffer. +; +;Permission to copy this software, to redistribute it, and to use it +;for any purpose is granted, subject to the following restrictions and +;understandings. +; +;1. Any copy made of this software must include this copyright notice +;in full. +; +;2. I have made no warrantee or representation that the operation of +;this software will be error-free, and I am under no obligation to +;provide any services, by way of maintenance, update, or otherwise. +; +;3. In conjunction with products arising from the use of this +;material, there shall be no use of my name in any advertising, +;promotional, or sales literature without prior written consent in +;each case. + +(require 'qp) + +;;;; BREAKPOINTS + +;;; Typing (init-debug) at top level sets up a continuation for +;;; breakpoint. When (breakpoint arg1 ...) is then called it returns +;;; from the top level continuation and pushes the continuation from +;;; which it was called on breakpoint:continuation-stack. If +;;; (continue) is later called, it pops the topmost continuation off +;;; of breakpoint:continuation-stack and returns #f to it. + +(define breakpoint:continuation-stack '()) + +(define debug:breakpoint + (let ((call-with-current-continuation call-with-current-continuation) + (apply apply) (qpn qpn) + (cons cons) (length length)) + (lambda args + (apply qpn "BREAKPOINT:" args) + (let ((ans + (call-with-current-continuation + (lambda (x) + (set! breakpoint:continuation-stack + (cons x breakpoint:continuation-stack)) + (debug:top-continuation + (length breakpoint:continuation-stack)))))) + (cond ((not (eq? ans breakpoint:continuation-stack)) ans)))))) + +(define debug:continue + (let ((null? null?) (car car) (cdr cdr)) + (lambda args + (cond ((null? breakpoint:continuation-stack) + (display "; no break to continue from") + (newline)) + (else + (let ((cont (car breakpoint:continuation-stack))) + (set! breakpoint:continuation-stack + (cdr breakpoint:continuation-stack)) + (if (null? args) (cont #f) + (apply cont args)))))))) + +(define debug:top-continuation + (if (provided? 'abort) + (lambda (val) (display val) (newline) (abort)) + (begin (display "; type (init-debug)") #f))) + +(define (init-debug) + (call-with-current-continuation + (lambda (x) (set! debug:top-continuation x)))) + +(define breakpoint debug:breakpoint) +(define bkpt debug:breakpoint) +(define continue debug:continue) + +(define debug:breakf + (let ((null? null?) ;These bindings are so that + (not not) ;breakf will not break on parts + (car car) (cdr cdr) ;of itself. + (eq? eq?) (+ +) (zero? zero?) (modulo modulo) + (apply apply) (display display) (breakpoint debug:breakpoint)) + (lambda (function . optname) +;;; (set! debug:indent 0) + (let ((name (if (null? optname) function (car optname)))) + (lambda args + (cond ((and (not (null? args)) + (eq? (car args) 'debug:unbreak-object) + (null? (cdr args))) + function) + (else + (breakpoint name args) + (apply function args)))))))) + +;;; the reason I use a symbol for debug:unbreak-object is so +;;; that functions can still be unbreaked if this file is read in twice. + +(define (debug:unbreakf function) +;;; (set! debug:indent 0) + (function 'debug:unbreak-object)) + +;;;;The break: functions wrap around the debug: functions to provide +;;; niceties like keeping track of breakd functions and dealing with +;;; redefinition. + +(require 'alist) +(define break:adder (alist-associator eq?)) +(define break:deler (alist-remover eq?)) + +(define *breakd-procedures* '()) +(define (break:breakf fun sym) + (cond ((not (procedure? fun)) + (display "WARNING: not a procedure " (current-error-port)) + (display sym (current-error-port)) + (newline (current-error-port)) + (set! *breakd-procedures* (break:deler *breakd-procedures* sym)) + fun) + (else + (let ((p (assq sym *breakd-procedures*))) + (cond ((and p (eq? (cdr p) fun)) + fun) + (else + (let ((tfun (debug:breakf fun sym))) + (set! *breakd-procedures* + (break:adder *breakd-procedures* sym tfun)) + tfun))))))) + +(define (break:unbreakf fun sym) + (let ((p (assq sym *breakd-procedures*))) + (set! *breakd-procedures* (break:deler *breakd-procedures* sym)) + (cond ((not (procedure? fun)) fun) + ((not p) fun) + ((eq? (cdr p) fun) + (debug:unbreakf fun)) + (else fun)))) + +(define breakf debug:breakf) +(define unbreakf debug:unbreakf) + +;;;; Finally, the macros break and unbreak + +(defmacro break xs + (if (null? xs) + `(begin ,@(map (lambda (x) `(set! ,x (break:breakf ,x ',x))) + (map car *breakd-procedures*)) + (map car *breakd-procedures*)) + `(begin ,@(map (lambda (x) `(set! ,x (break:breakf ,x ',x))) xs)))) +(defmacro unbreak xs + (if (null? xs) + (slib:eval + `(begin ,@(map (lambda (x) `(set! ,x (break:unbreakf ,x ',x))) + (map car *breakd-procedures*)) + '',(map car *breakd-procedures*))) + `(begin ,@(map (lambda (x) `(set! ,x (break:unbreakf ,x ',x))) xs)))) |