diff options
| author |  Peter McGoron
| 2024-08-22 20:05:49 -0400 |
|---|---|---|
| committer | Peter McGoron
| 2024-08-22 20:05:49 -0400 |
| commit | 45cfd8ff11770f7dcfbb1c0fe4ff1434565d896a (patch) | |
| tree | d1f7439291db49cdabe22fcf80a556e3f95966fa | |
add doubly linked lists, tests, minischeme
| -rw-r--r-- | COPYING | 674 | ||||
| -rw-r--r-- | Makefile | 8 | ||||
| -rw-r--r-- | README.rst | 24 | ||||
| -rw-r--r-- | doubly-linked-list.scm | 332 | ||||
| -rw-r--r-- | miniscm/init.scm | 78 | ||||
| -rw-r--r-- | miniscm/miniscm.c | 2443 | ||||
| -rw-r--r-- | tests.scm | 57 |
7 files changed, 3616 insertions, 0 deletions
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Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +<https://www.gnu.org/licenses/>. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +<https://www.gnu.org/licenses/why-not-lgpl.html>. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..357e144 --- /dev/null +++ b/Makefile @@ -0,0 +1,8 @@ +.POSIX: + +miniscm-run-tests: miniscm/scm tests.scm + ./miniscm/scm < tests.scm +miniscm/scm: + c89 -DSYSV -DInitFile=\"miniscm/init.scm\" miniscm/miniscm.c -o miniscm/scm +clean: + rm -f miniscm diff --git a/README.rst b/README.rst new file mode 100644 index 0000000..cd78e66 --- /dev/null +++ b/README.rst @@ -0,0 +1,24 @@ +======= +UNSLISP +======= + +R7RS compiler written in a basic form of Scheme. Compiles to Universal +Service GLLV bytecode. + +License: GPL-3.0-only + +------------------- +Source Restrictions +------------------- + +Although the compiler handles all of R7RS, the source of UNSLISP is +designed to be used by a severely limited Scheme interpreter, which + +* lacks ``call/cc``, ``call-with-values``, etc +* lacks user definable macros +* only uses required features from R3RS +* has fixnums only +* minimizes the use of strings +* does not use "load" recursively + +The goal is to have the compiler run under MiniScheme 0.85 in DOS. diff --git a/doubly-linked-list.scm b/doubly-linked-list.scm new file mode 100644 index 0000000..fa6bd20 --- /dev/null +++ b/doubly-linked-list.scm @@ -0,0 +1,332 @@ +;;; Copyright (C) Peter McGoron 2024 +;;; This program is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, version 3 of the License. +;;; +;;; This program is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with this program. If not, see <https://www.gnu.org/licenses/>. + +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; Code to handle the linked list container. +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; +;;; The container is constructed with DL:CTR and has two fields, +;;; head and tail which point to the start and end of the list. + +;;; (DL:CTR) constructs an empty doubly linked list container. +(define dl:ctr + (lambda () (cons '() '()))) + +(define dl:head car) +(define dl:set-head! set-car!) +(define dl:tail cdr) +(define dl:set-tail! set-cdr!) + +;;; (DL:EMPTY? CTR) tests if CTR is a list of zero elements. +(define dl:empty? + (lambda (ctr) + (null? (dl:head ctr)))) + +;;; (DL:ADD-FIRST-ELEMENT CTR ELEM) initializes CTR to be a list of one +;;; element ELEM. +(define dl:add-first-element + (lambda (ctr elem) + (dl:set-head! ctr elem) + (dl:set-tail! ctr elem))) + +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; Code to handle list elements +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; List elements are constructed with (DL:ELEM VAL), where VAL is the +;;; value to be stored in the list. + +;;; (DL:ELEM VAL) constructs a new doubly linked list element with element +;;; VAL. +(define dl:elem + (lambda (val) + (vector '() val '()))) + +(define dl:prev + (lambda (elem) (vector-ref elem 0))) +(define dl:set-prev! + (lambda (elem prev) (vector-set! elem 0 prev))) + +(define dl:val + (lambda (elem) (vector-ref elem 1))) + +(define dl:val-equal? + (lambda (elem x) (equal? (dl:val elem) x))) + +(define dl:next + (lambda (elem) (vector-ref elem 2))) +(define dl:set-next! + (lambda (elem next) (vector-set! elem 2 next))) + +(define dl:is-head? + (lambda (ctr elem) + (eqv? (dl:head ctr) elem))) + +(define dl:is-tail? + (lambda (ctr elem) + (eqv? (dl:tail ctr) elem))) + +(define dl:link + (lambda (before after) + (dl:set-next! before after) + (dl:set-prev! after before))) + +(define dl:unlink + (lambda (elem) + (let ((prev (dl:prev elem)) + (next (dl:next elem))) + (if (not (null? prev)) + (dl:set-next! prev next) + '()) + (if (not (null? next)) + (dl:set-prev! next prev) + '()) + (dl:set-prev! elem '()) + (dl:set-next! elem '())))) + +;;; ;;;;;;;;;;;;;;;;;;;;;; +;;; Linked List operations +;;; ;;;;;;;;;;;;;;;;;;;;;; + +;;; (DL:PUSH CTR ELEM) pushes ELEM to the head of the list in CTR. +;;; The element after ELEM is the previous head. +(define dl:push + (lambda (ctr elem) + (if (dl:empty? ctr) + (dl:add-first-element ctr elem) + (begin + (dl:set-prev! elem '()) + (dl:link elem (dl:head ctr)) + (dl:set-head! ctr elem))))) + +;;; (DL:PUSH-TAIL CTR ELEM) pushes ELEM to the tail of the list in CTR. +;;; The element before ELEM is the previous tail. +(define dl:push-tail + (lambda (ctr elem) + (if (dl:empty? ctr) + (dl:add-first-element ctr elem) + (begin + (dl:set-next! elem '()) + (dl:link (dl:tail ctr) elem) + (dl:set-tail! ctr elem))))) + +;;; (DL:FIND CTR OK?) searches CTR for the first element whose value +;;; VAL satisfies (OK? VAL). If there is no element, the function +;;; returns #F. +(define dl:find + (lambda (ctr ok?) + (letrec + ((loop + (lambda (element) + (cond + ((null? element) #f) + ((ok? (dl:val element)) element) + (else (loop (dl:next element))))))) + (loop (dl:head ctr))))) + +;;; (DL:FIND-EQUAL CTR VAL) searches CTR for the first element such that +;;; (EQUAL? CTR (DL:VAL ELEM)). See documentation for DL:FIND +(define dl:find-equal + (lambda (ctr val) (dl:find ctr (lambda (x) + (equal? val x))))) + +;;; (DL:INSERT-BEFORE CTR ELEM TO-BE-INSERTED) +;;; places TO-BE-INSERTED in the list before ELEM. ELEM must be a part of +;;; the list. +(define dl:insert-before + (lambda (ctr elem to-be-inserted) + (if (dl:is-head? ctr elem) + (dl:push ctr to-be-inserted) + (let ((prev (dl:prev elem))) + (dl:link prev to-be-inserted) + (dl:link to-be-inserted elem))))) + +;;; (DL:INSERT-AFTER CTR ELEM TO-BE-INSERTED) +;;; places TO-BE-INSERTED in the list after ELEM. ELEM must be a part of +;;; the list. +(define dl:insert-after + (lambda (ctr elem to-be-inserted) + (if (dl:is-tail? ctr elem) + (dl:push-tail ctr to-be-inserted) + (let ((next (dl:next elem))) + (dl:link to-be-inserted next) + (dl:link elem to-be-inserted))))) + +;;; (DL:REMOVE CTR ELEM) removes ELEM from the list by linking the +;;; previous and next elements of the list together (if they exist). +(define dl:remove + (lambda (ctr elem) + (let ((was-head? (dl:is-head? ctr elem)) + (was-tail? (dl:is-tail? ctr elem)) + (prev (dl:prev elem)) + (next (dl:next elem))) + (dl:unlink elem) + (if was-head? + (dl:set-head! ctr next) + #f) + (if was-tail? + (dl:set-tail! ctr tail) + #f)))) + +;;; (DL:PUSH-LIST-BACK CTR LST) appends LST to CTR. +(define dl:push-list-back + (lambda (ctr lst) + (if (null? lst) + ctr + (begin + (dl:push-tail ctr (dl:elem (car lst))) + (dl:push-list-back ctr (cdr lst)))))) + +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; Tests +;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +(define %dl:equal-to-list? + (lambda (ctr lst) + (letrec + ((xor? + (lambda (x y) + (if x (not y) y))) + (loop + (lambda (dl-elem lst-elem) + (if (not (dl:val-equal? dl-elem (car lst-elem))) + #f + (let ((dl-next (dl:next dl-elem)) + (lst-next (cdr lst-elem))) + (if (xor? (null? dl-next) (null? lst-next)) + #f + (if (null? dl-next) + #t + (loop dl-next lst-next)))))))) + (loop (dl:head ctr) lst)))) + +(define %dl:find-remove + (lambda (ctr val) + (let ((elem (dl:find-equal ctr val))) + (if elem + (begin + (dl:remove ctr elem) + #t) + #f)))) + +(define %dl:find-remove-from-list + (lambda (ctr lst) + (if (null? lst) + #t + (if (not (%dl:find-remove ctr (car lst))) + #f + (%dl:find-remove-from-list ctr (cdr lst)))))) + +(define %dl:test-insert-into-list + (lambda (original-list searched-value value-to-insert + insert-direction modified-list) + (let ((ctr (dl:ctr))) + (dl:push-list-back ctr original-list) + (let ((searched-elem (dl:find-equal ctr searched-value))) + (if (not searched-elem) + #f + (begin + (insert-direction ctr + searched-elem + (dl:elem value-to-insert)) + (%dl:equal-to-list? ctr modified-list))))))) + +(define %dl:tests + (list + (cons "insert one in front" + (lambda () + (let ((ctr (dl:ctr))) + (dl:push ctr (dl:elem 5)) + (%dl:equal-to-list? ctr '(5))))) + (cons "insert one in back" + (lambda () + (let ((ctr (dl:ctr))) + (dl:push-tail ctr (dl:elem 5)) + (%dl:equal-to-list? ctr '(5))))) + (cons "insert many" + (lambda () + (let ((ctr (dl:ctr)) + (to-insert '(1 2 3 4 5))) + (dl:push-list-back ctr to-insert) + (%dl:equal-to-list? ctr '(1 2 3 4 5))))) + (cons "insert then delete" + (lambda () + (let ((ctr (dl:ctr)) + (el (dl:elem 5))) + (dl:push ctr el) + (dl:remove ctr el) + (dl:empty? ctr)))) + (cons "insert many then delete all" + (lambda () + (let ((ctr (dl:ctr)) + (vals '(1 2 3 4 5))) + (dl:push-list-back ctr vals) + (if (not (%dl:find-remove-from-list ctr vals)) + #f + (dl:empty? ctr))))) + (cons "insert many then delete some" + (lambda () + (let ((ctr (dl:ctr))) + (dl:push-list-back ctr '(1 2 3 4 5 6 7 8 9 10)) + (if (not (%dl:find-remove-from-list ctr '(1 2 5 7 10))) + #f + (%dl:equal-to-list? ctr '(3 4 6 8 9)))))) + (cons "push head many" + (lambda () + (let ((ctr (dl:ctr))) + (dl:push ctr (dl:elem 1)) + (dl:push ctr (dl:elem 2)) + (dl:push ctr (dl:elem 3)) + (%dl:equal-to-list? ctr '(3 2 1))))) + (cons "insert before in the middle" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 3 + 10 + dl:insert-before + '(1 2 10 3 4 5)))) + (cons "insert before at head" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 1 + 10 + dl:insert-before + '(10 1 2 3 4 5)))) + (cons "insert before at tail" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 5 + 10 + dl:insert-before + '(1 2 3 4 10 5)))) + (cons "insert after in middle" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 3 + 10 + dl:insert-after + '(1 2 3 10 4 5)))) + (cons "insert after at head" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 1 + 10 + dl:insert-after + '(1 10 2 3 4 5)))) + (cons "insert after at tail" + (lambda () + (%dl:test-insert-into-list '(1 2 3 4 5) + 5 + 10 + dl:insert-after + '(1 2 3 4 5 10)))))) + diff --git a/miniscm/init.scm b/miniscm/init.scm new file mode 100644 index 0000000..cbc8e37 --- /dev/null +++ b/miniscm/init.scm @@ -0,0 +1,78 @@ +; This is a init file for Mini-Scheme. +; Modified for UNSLISP. + +(define (caar x) (car (car x))) +(define (cadr x) (car (cdr x))) +(define (cdar x) (cdr (car x))) +(define (cddr x) (cdr (cdr x))) +(define (caaar x) (car (car (car x)))) +(define (caadr x) (car (car (cdr x)))) +(define (cadar x) (car (cdr (car x)))) +(define (caddr x) (car (cdr (cdr x)))) +(define (cdaar x) (cdr (car (car x)))) +(define (cdadr x) (cdr (car (cdr x)))) +(define (cddar x) (cdr (cdr (car x)))) +(define (cdddr x) (cdr (cdr (cdr x)))) + +(define (list . x) x) + +(define (map proc list) + (if (pair? list) + (cons (proc (car list)) (map proc (cdr list))))) + +(define (for-each proc list) + (if (pair? list) + (begin (proc (car list)) (for-each proc (cdr list))) + #t )) + +(define (list-tail x k) + (if (zero? k) + x + (list-tail (cdr x) (- k 1)))) + +(define (list-ref x k) + (car (list-tail x k))) + +(define list-set! + (lambda (lst k obj) + (if (= k 0) + (set-car! lst obj) + (list-set! (cdr lst) (- k 1) obj)))) + +(define (last-pair x) + (if (pair? (cdr x)) + (last-pair (cdr x)) + x)) + +(define vector list) +(define vector-ref list-ref) +(define vector-set! list-set!) + +(define (head stream) (car stream)) + +(define (tail stream) (force (cdr stream))) + +;;;;; following part is written by a.k + +;;;; atom? +(define (atom? x) + (not (pair? x))) + +;;;; memq +(define (memq obj lst) + (cond + ((null? lst) #f) + ((eq? obj (car lst)) lst) + (else (memq obj (cdr lst))))) + +;;;; equal? +(define (equal? x y) + (if (pair? x) + (and (pair? y) + (equal? (car x) (car y)) + (equal? (cdr x) (cdr y))) + (and (not (pair? y)) + (eqv? x y)))) + +(display "This is a limited version of MiniScheme used to run UNSLISP.") + diff --git a/miniscm/miniscm.c b/miniscm/miniscm.c new file mode 100644 index 0000000..ea4dc90 --- /dev/null +++ b/miniscm/miniscm.c @@ -0,0 +1,2443 @@ +/* + * ---------- Mini-Scheme Interpreter Version 0.85 ---------- + * + * coded by Atsushi Moriwaki (11/5/1989) + * + * E-MAIL : moriwaki@kurims.kurims.kyoto-u.ac.jp + * + * THIS SOFTWARE IS IN THE PUBLIC DOMAIN + * ------------------------------------ + * This software is completely free to copy, modify and/or re-distribute. + * But I would appreciate it if you left my name on the code as the author. + * + */ +/*-- + * + * This version has been modified by R.C. Secrist. + * + * Mini-Scheme is now maintained by Akira KIDA. + * + * This is a revised and modified version by Akira KIDA. + * current version is 0.85k4 (15 May 1994) + * + * Please send suggestions, bug reports and/or requests to: + * <SDI00379@niftyserve.or.jp> + *-- + */ + +/* + * Here is System declaration. + * Please define exactly one symbol in the following section. + */ +/* #define LSC */ /* LightSpeed C for Macintosh */ +/* #define LSC4 */ /* THINK C version 4.0 for Macintosh */ +/* #define MPW2 */ /* Macintosh Programmer's Workshop v2.0x */ +/* #define BSD */ /* 4.x BSD */ +/* #define MSC */ /* Microsoft C Compiler v.4.00 - 7.00 */ +/* #define TURBOC */ /* Turbo C compiler v.2.0, or TC++ 1.0 */ +/* #define SYSV */ /* System-V, or POSIX */ +/* #define VAXC */ /* VAX/VMS VAXC 2.x or later */ /* (automatic) */ + +#ifdef __BORLANDC__ /* Borland C++ - MS-DOS */ +#define TURBOC +#endif + +#ifdef __TURBOC__ /* Turbo C V1.5 - MS-DOS */ +#define TURBOC +#endif + +#ifdef mips /* DECstation running OSF/1 */ +#define BSD +#endif + +#ifdef __osf__ /* Alpha AXP running OSF/1 */ +#define BSD +#endif + +#ifdef __DECC /* Alpha AXP running VMS */ +#define VAXC +#endif + +#ifdef _AIX /* RS/6000 running AIX */ +#define BSD +#endif + +/* + * Define or undefine following symbols as you need. + */ +/* #define VERBOSE */ /* define this if you want verbose GC */ +#define AVOID_HACK_LOOP /* define this if your compiler is poor + * enougth to complain "do { } while (0)" + * construction. + */ +#define USE_SETJMP /* undef this if you do not want to use setjmp() */ +#define USE_QQUOTE /* undef this if you do not need quasiquote */ +#define USE_MACRO /* undef this if you do not need macro */ + + +#ifdef USE_QQUOTE +/*-- + * If your machine can't support "forward single quotation character" + * i.e., '`', you may have trouble to use backquote. + * So use '^' in place of '`'. + */ +# define BACKQUOTE '`' +#endif + +/* + * Basic memory allocation units + */ + +#ifdef TURBOC /* rcs */ +#define CELL_SEGSIZE 2048 +#define CELL_NSEGMENT 100 +#define STR_SEGSIZE 2048 +#define STR_NSEGMENT 100 +#else +#define CELL_SEGSIZE 5000 /* # of cells in one segment */ +#define CELL_NSEGMENT 100 /* # of segments for cells */ +#define STR_SEGSIZE 2500 /* bytes of one string segment */ +#define STR_NSEGMENT 100 /* # of segments for strings */ +#endif + + + +#define banner "Hello, This is Mini-Scheme Interpreter Version 0.85k4-a.\n" + + +#include <stdio.h> +#include <ctype.h> +#ifdef USE_SETJMP +#include <setjmp.h> +#endif + + +/* System dependency */ +#ifdef LSC +#include <strings.h> +#include <unix.h> +#define malloc(x) NewPtr((long)(x)) +#define prompt "> " +#define FIRST_CELLSEGS 5 +#endif + +#ifdef LSC4 +#include <string.h> +#include <stdlib.h> +#define malloc(x) NewPtr((long)(x)) +#define prompt "> " +#define FIRST_CELLSEGS 5 +#endif + +#ifdef MPW2 +#include <strings.h> +#include <memory.h> +#define malloc(x) NewPtr((long)(x)) +#define prompt "> [enter at next line]\n" +#define FIRST_CELLSEGS 5 +#endif + +#ifdef BSD +#include <strings.h> +#include <signal.h> +#define prompt "> " +#define FIRST_CELLSEGS 10 +#endif + +#ifdef MSC +#include <string.h> +#include <stdlib.h> +#include <malloc.h> +#include <process.h> +#define prompt "> " +#define FIRST_CELLSEGS 3 +#endif + +#ifdef TURBOC +#include <string.h> +#include <stdlib.h> +#define prompt "> " +#define FIRST_CELLSEGS 3 +#endif + +#ifdef SYSV +#include <string.h> +#include <malloc.h> +#if __STDC__ +# include <stdlib.h> +#endif +#define prompt "> " +#define FIRST_CELLSEGS 10 +#endif + +#ifdef VAXC +#include <string.h> +#include <stdlib.h> +#define prompt "> " +#define FIRST_CELLSEGS 10 +#endif + +#ifdef __GNUC__ +/* + * If we use gcc, AVOID_HACK_LOOP is unnecessary + */ +#undef AVOID_HACK_LOOP +#endif + +#ifndef FIRST_CELLSEGS +#error Please define your system type. +/* + * We refrain this to raise an error anyway even if on pre-ANSI system. + */ +error Please define your system type. +#endif + +/* cell structure */ +struct cell { + unsigned short _flag; + union { + struct { + char *_svalue; + short _keynum; + } _string; + struct { + long _ivalue; + } _number; + struct { + struct cell *_car; + struct cell *_cdr; + } _cons; + } _object; +}; + +typedef struct cell *pointer; + +#define T_STRING 1 /* 0000000000000001 */ +#define T_NUMBER 2 /* 0000000000000010 */ +#define T_SYMBOL 4 /* 0000000000000100 */ +#define T_SYNTAX 8 /* 0000000000001000 */ +#define T_PROC 16 /* 0000000000010000 */ +#define T_PAIR 32 /* 0000000000100000 */ +#define T_CLOSURE 64 /* 0000000001000000 */ +#define T_CONTINUATION 128 /* 0000000010000000 */ +#ifdef USE_MACRO +# define T_MACRO 256 /* 0000000100000000 */ +#endif +#define T_PROMISE 512 /* 0000001000000000 */ +#define T_ATOM 16384 /* 0100000000000000 */ /* only for gc */ +#define CLRATOM 49151 /* 1011111111111111 */ /* only for gc */ +#define MARK 32768 /* 1000000000000000 */ +#define UNMARK 32767 /* 0111111111111111 */ + +/* macros for cell operations */ +#define type(p) ((p)->_flag) + +#define isstring(p) (type(p)&T_STRING) +#define strvalue(p) ((p)->_object._string._svalue) +#define keynum(p) ((p)->_object._string._keynum) + +#define isnumber(p) (type(p)&T_NUMBER) +#define ivalue(p) ((p)->_object._number._ivalue) + +#define ispair(p) (type(p)&T_PAIR) +#define car(p) ((p)->_object._cons._car) +#define cdr(p) ((p)->_object._cons._cdr) + +#define issymbol(p) (type(p)&T_SYMBOL) +#define symname(p) strvalue(car(p)) +#define hasprop(p) (type(p)&T_SYMBOL) +#define symprop(p) cdr(p) + +#define issyntax(p) (type(p)&T_SYNTAX) +#define isproc(p) (type(p)&T_PROC) +#define syntaxname(p) strvalue(car(p)) +#define syntaxnum(p) keynum(car(p)) +#define procnum(p) ivalue(p) + +#define isclosure(p) (type(p)&T_CLOSURE) +#ifdef USE_MACRO +# define ismacro(p) (type(p)&T_MACRO) +#endif +#define closure_code(p) car(p) +#define closure_env(p) cdr(p) + +#define iscontinuation(p) (type(p)&T_CONTINUATION) +#define cont_dump(p) cdr(p) + +#define ispromise(p) (type(p)&T_PROMISE) +#define setpromise(p) type(p) |= T_PROMISE + +#define isatom(p) (type(p)&T_ATOM) +#define setatom(p) type(p) |= T_ATOM +#define clratom(p) type(p) &= CLRATOM + +#define ismark(p) (type(p)&MARK) +#define setmark(p) type(p) |= MARK +#define clrmark(p) type(p) &= UNMARK + +#define caar(p) car(car(p)) +#define cadr(p) car(cdr(p)) +#define cdar(p) cdr(car(p)) +#define cddr(p) cdr(cdr(p)) +#define cadar(p) car(cdr(car(p))) +#define caddr(p) car(cdr(cdr(p))) +#define cadaar(p) car(cdr(car(car(p)))) +#define cadddr(p) car(cdr(cdr(cdr(p)))) +#define cddddr(p) cdr(cdr(cdr(cdr(p)))) + +/* arrays for segments */ +pointer cell_seg[CELL_NSEGMENT]; +int last_cell_seg = -1; +char *str_seg[STR_NSEGMENT]; +int str_seglast = -1; + +/* We use 4 registers. */ +pointer args; /* register for arguments of function */ +pointer envir; /* stack register for current environment */ +pointer code; /* register for current code */ +pointer dump; /* stack register for next evaluation */ + +struct cell _NIL; +pointer NIL = &_NIL; /* special cell representing empty cell */ +struct cell _T; +pointer T = &_T; /* special cell representing #t */ +struct cell _F; +pointer F = &_F; /* special cell representing #f */ +pointer oblist = &_NIL; /* pointer to symbol table */ +pointer global_env; /* pointer to global environment */ + +/* global pointers to special symbols */ +pointer LAMBDA; /* pointer to syntax lambda */ +pointer QUOTE; /* pointer to syntax quote */ + +#ifdef USE_QQUOTE +pointer QQUOTE; /* pointer to symbol quasiquote */ +pointer UNQUOTE; /* pointer to symbol unquote */ +pointer UNQUOTESP; /* pointer to symbol unquote-splicing */ + +#endif + +pointer free_cell = &_NIL; /* pointer to top of free cells */ +long fcells = 0; /* # of free cells */ + +FILE *infp; /* input file */ +FILE *outfp; /* output file */ + +#ifdef USE_SETJMP +jmp_buf error_jmp; + +#endif +char gc_verbose; /* if gc_verbose is not zero, print gc status */ + +/* allocate new cell segment */ +alloc_cellseg(n) +int n; +{ + register pointer p; + register long i; + register int k; + + for (k = 0; k < n; k++) { + if (last_cell_seg >= CELL_NSEGMENT - 1) + return k; + p = (pointer) malloc(CELL_SEGSIZE * sizeof(struct cell)); + if (p == (pointer) 0) + return k; + cell_seg[++last_cell_seg] = p; + fcells += CELL_SEGSIZE; + for (i = 0; i < CELL_SEGSIZE - 1; i++, p++) { + type(p) = 0; + car(p) = NIL; + cdr(p) = p + 1; + } + type(p) = 0; + car(p) = NIL; + cdr(p) = free_cell; + free_cell = cell_seg[last_cell_seg]; + } + return n; +} + +/* allocate new string segment */ +alloc_strseg(n) +int n; +{ + register char *p; + register long i; + register int k; + + for (k = 0; k < n; k++) { + if (str_seglast >= STR_NSEGMENT) + return k; + p = (char *) malloc(STR_SEGSIZE * sizeof(char)); + if (p == (char *) 0) + return k; + str_seg[++str_seglast] = p; + for (i = 0; i < STR_SEGSIZE; i++) + *p++ = (char) (-1); + } + return n; +} + +/* initialization of Mini-Scheme */ +init_scheme() +{ + register pointer i; + + if (alloc_cellseg(FIRST_CELLSEGS) != FIRST_CELLSEGS) + FatalError("Unable to allocate initial cell segments"); + if (!alloc_strseg(1)) + FatalError("Unable to allocate initial string segments"); +#ifdef VERBOSE + gc_verbose = 1; +#else + gc_verbose = 0; +#endif + init_globals(); +} + +/* get new cell. parameter a, b is marked by gc. */ +pointer get_cell(a, b) +register pointer a, b; +{ + register pointer x; + + if (free_cell == NIL) { + gc(a, b); + if (free_cell == NIL) +#ifdef USE_SETJMP + if (!alloc_cellseg(1)) { + args = envir = code = dump = NIL; + gc(NIL, NIL); + if (free_cell != NIL) + Error("run out of cells --- rerurn to top level"); + else + FatalError("run out of cells --- unable to recover cells"); + } +#else + if (!alloc_cellseg(1)) + FatalError("run out of cells --- unable to recover cells"); +#endif + } + x = free_cell; + free_cell = cdr(x); + --fcells; + return (x); +} + +/* get new cons cell */ +pointer cons(a, b) +register pointer a, b; +{ + register pointer x = get_cell(a, b); + + type(x) = T_PAIR; + car(x) = a; + cdr(x) = b; + return (x); +} + +/* get number atom */ +pointer mk_number(num) +register long num; +{ + register pointer x = get_cell(NIL, NIL); + + type(x) = (T_NUMBER | T_ATOM); + ivalue(x) = num; + return (x); +} + +/* allocate name to string area */ +char *store_string(name) +char *name; +{ + register char *q; + register short i; + long len, remain; + + /* first check name has already listed */ + for (i = 0; i <= str_seglast; i++) + for (q = str_seg[i]; *q != (char) (-1); ) { + if (!strcmp(q, name)) + goto FOUND; + while (*q++) + ; /* get next string */ + } + len = strlen(name) + 2; + remain = (long) STR_SEGSIZE - ((long) q - (long) str_seg[str_seglast]); + if (remain < len) { + if (!alloc_strseg(1)) + FatalError("run out of string area"); + q = str_seg[str_seglast]; + } + strcpy(q, name); +FOUND: + return (q); +} + +/* get new string */ +pointer mk_string(str) +char *str; +{ + register pointer x = get_cell(NIL, NIL); + + strvalue(x) = store_string(str); + type(x) = (T_STRING | T_ATOM); + keynum(x) = (short) (-1); + return (x); +} + +/* get new symbol */ +pointer mk_symbol(name) +char *name; +{ + register pointer x; + + /* fisrt check oblist */ + for (x = oblist; x != NIL; x = cdr(x)) + if (!strcmp(name, symname(car(x)))) + break; + + if (x != NIL) + return (car(x)); + else { + x = cons(mk_string(name), NIL); + type(x) = T_SYMBOL; + oblist = cons(x, oblist); + return (x); + } +} + +/* make symbol or number atom from string */ +pointer mk_atom(q) +char *q; +{ + char c, *p; + + p = q; + if (!isdigit(c = *p++)) { + if ((c != '+' && c != '-') || !isdigit(*p)) + return (mk_symbol(q)); + } + for ( ; (c = *p) != 0; ++p) + if (!isdigit(c)) + return (mk_symbol(q)); + return (mk_number(atol(q))); +} + +/* make constant */ +pointer mk_const(name) +char *name; +{ + long x; + char tmp[256]; + + if (!strcmp(name, "t")) + return (T); + else if (!strcmp(name, "f")) + return (F); + else if (*name == 'o') {/* #o (octal) */ + sprintf(tmp, "0%s", &name[1]); + sscanf(tmp, "%lo", &x); + return (mk_number(x)); + } else if (*name == 'd') { /* #d (decimal) */ + sscanf(&name[1], "%ld", &x); + return (mk_number(x)); + } else if (*name == 'x') { /* #x (hex) */ + sprintf(tmp, "0x%s", &name[1]); + sscanf(tmp, "%lx", &x); + return (mk_number(x)); + } else + return (NIL); +} + + +/* ========== garbage collector ========== */ + +/*-- + * We use algorithm E (Kunuth, The Art of Computer Programming Vol.1, + * sec.3.5) for marking. + */ +mark(a) +pointer a; +{ + register pointer t, q, p; + +E1: t = (pointer) 0; + p = a; +E2: setmark(p); +E3: if (isatom(p)) + goto E6; +E4: q = car(p); + if (q && !ismark(q)) { + setatom(p); + car(p) = t; + t = p; + p = q; + goto E2; + } +E5: q = cdr(p); + if (q && !ismark(q)) { + cdr(p) = t; + t = p; + p = q; + goto E2; + } +E6: if (!t) + return; + q = t; + if (isatom(q)) { + clratom(q); + t = car(q); + car(q) = p; + p = q; + goto E5; + } else { + t = cdr(q); + cdr(q) = p; + p = q; + goto E6; + } +} + + +/* garbage collection. parameter a, b is marked. */ +gc(a, b) +register pointer a, b; +{ + register pointer p; + register short i; + register long j; + + if (gc_verbose) + printf("gc..."); + + /* mark system globals */ + mark(oblist); + mark(global_env); + + /* mark current registers */ + mark(args); + mark(envir); + mark(code); + mark(dump); + + /* mark variables a, b */ + mark(a); + mark(b); + + /* garbage collect */ + clrmark(NIL); + fcells = 0; + free_cell = NIL; + for (i = 0; i <= last_cell_seg; i++) { + for (j = 0, p = cell_seg[i]; j < CELL_SEGSIZE; j++, p++) { + if (ismark(p)) + clrmark(p); + else { + type(p) = 0; + cdr(p) = free_cell; + car(p) = NIL; + free_cell = p; + ++fcells; + } + } + } + + if (gc_verbose) + printf(" done %ld cells are recovered.\n", fcells); +} + + +/* ========== Rootines for Reading ========== */ + +#define TOK_LPAREN 0 +#define TOK_RPAREN 1 +#define TOK_DOT 2 +#define TOK_ATOM 3 +#define TOK_QUOTE 4 +#define TOK_COMMENT 5 +#define TOK_DQUOTE 6 +#ifdef USE_QQUOTE +# define TOK_BQUOTE 7 +# define TOK_COMMA 8 +# define TOK_ATMARK 9 +#endif +#define TOK_SHARP 10 + +#define LINESIZE 1024 +char linebuff[LINESIZE]; +char strbuff[256]; +char *currentline = linebuff; +char *endline = linebuff; + +/* get new character from input file */ +int inchar() +{ + if (currentline >= endline) { /* input buffer is empty */ + if (feof(infp)) { + fclose(infp); + infp = stdin; + printf(prompt); + } + strcpy(linebuff, "\n"); + if (fgets(currentline = linebuff, LINESIZE, infp) == NULL) + if (infp == stdin) { + fprintf(stderr, "Good-bye\n"); + exit(0); + } + endline = linebuff + strlen(linebuff); + } + return (*currentline++); +} + +/* clear input buffer */ +clearinput() +{ + currentline = endline = linebuff; +} + +/* back to standard input */ +flushinput() +{ + if (infp != stdin) { + fclose(infp); + infp = stdin; + } + clearinput(); +} + +/* back character to input buffer */ +backchar() +{ + currentline--; +} + +/* read chacters to delimiter */ +char *readstr(delim) +char *delim; +{ + char *p = strbuff; + + while (isdelim(delim, (*p++ = inchar()))) + ; + backchar(); + *--p = '\0'; + return (strbuff); +} + +/* read string expression "xxx...xxx" */ +char *readstrexp() +{ + char c, *p = strbuff; + + for (;;) { + if ((c = inchar()) != '"') + *p++ = c; + else if (p > strbuff && *(p - 1) == '\\') + *(p - 1) = '"'; + else { + *p = '\0'; + return (strbuff); + } + } +} + +/* check c is delimiter */ +isdelim(s, c) +char *s; +char c; +{ + while (*s) + if (*s++ == c) + return (0); + return (1); +} + +/* skip white characters */ +skipspace() +{ + while (isspace(inchar())) + ; + backchar(); +} + +/* get token */ +token() +{ + skipspace(); + switch (inchar()) { + case '(': + return (TOK_LPAREN); + case ')': + return (TOK_RPAREN); + case '.': + return (TOK_DOT); + case '\'': + return (TOK_QUOTE); + case ';': + return (TOK_COMMENT); + case '"': + return (TOK_DQUOTE); +#ifdef USE_QQUOTE + case BACKQUOTE: + return (TOK_BQUOTE); + case ',': + if (inchar() == '@') + return (TOK_ATMARK); + else { + backchar(); + return (TOK_COMMA); + } +#endif + case '#': + return (TOK_SHARP); + default: + backchar(); + return (TOK_ATOM); + } +} + +/* ========== Rootines for Printing ========== */ +#define ok_abbrev(x) (ispair(x) && cdr(x) == NIL) + +strunquote(p, s) +char *p; +char *s; +{ + *p++ = '"'; + for ( ; *s; ++s) { + if (*s == '"') { + *p++ = '\\'; + *p++ = '"'; + } else if (*s == '\n') { + *p++ = '\\'; + *p++ = 'n'; + } else + *p++ = *s; + } + *p++ = '"'; + *p = '\0'; +} + + +/* print atoms */ +int printatom(l, f) +pointer l; +int f; +{ + char *p; + + if (l == NIL) + p = "()"; + else if (l == T) + p = "#t"; + else if (l == F) + p = "#f"; + else if (isnumber(l)) { + p = strbuff; + sprintf(p, "%ld", ivalue(l)); + } else if (isstring(l)) { + if (!f) + p = strvalue(l); + else { + p = strbuff; + strunquote(p, strvalue(l)); + } + } else if (issymbol(l)) + p = symname(l); + else if (isproc(l)) { + p = strbuff; + sprintf(p, "#<PROCEDURE %ld>", procnum(l)); +#ifdef USE_MACRO + } else if (ismacro(l)) { + p = "#<MACRO>"; +#endif + } else if (isclosure(l)) + p = "#<CLOSURE>"; + else if (iscontinuation(l)) + p = "#<CONTINUATION>"; + if (f < 0) + return strlen(p); + fputs(p, outfp); + return 0; +} + + +/* ========== Rootines for Evaluation Cycle ========== */ + +/* make closure. c is code. e is environment */ +pointer mk_closure(c, e) +register pointer c, e; +{ + register pointer x = get_cell(c, e); + + type(x) = T_CLOSURE; + car(x) = c; + cdr(x) = e; + return (x); +} + +/* make continuation. */ +pointer mk_continuation(d) +register pointer d; +{ + register pointer x = get_cell(NIL, d); + + type(x) = T_CONTINUATION; + cont_dump(x) = d; + return (x); +} + +/* reverse list -- make new cells */ +pointer reverse(a) +register pointer a; /* a must be checked by gc */ +{ + register pointer p = NIL; + + for ( ; ispair(a); a = cdr(a)) + p = cons(car(a), p); + return (p); +} + +/* reverse list --- no make new cells */ +pointer non_alloc_rev(term, list) +pointer term, list; +{ + register pointer p = list, result = term, q; + + while (p != NIL) { + q = cdr(p); + cdr(p) = result; + result = p; + p = q; + } + return (result); +} + +/* append list -- make new cells */ +pointer append(a, b) +register pointer a, b; +{ + register pointer p = b, q; + + if (a != NIL) { + a = reverse(a); + while (a != NIL) { + q = cdr(a); + cdr(a) = p; + p = a; + a = q; + } + } + return (p); +} + +/* equivalence of atoms */ +eqv(a, b) +register pointer a, b; +{ + if (isstring(a)) { + if (isstring(b)) + return (strvalue(a) == strvalue(b)); + else + return (0); + } else if (isnumber(a)) { + if (isnumber(b)) + return (ivalue(a) == ivalue(b)); + else + return (0); + } else + return (a == b); +} + +/* true or false value macro */ +#define istrue(p) ((p) != NIL && (p) != F) +#define isfalse(p) ((p) == NIL || (p) == F) + +/* Error macro */ +#ifdef AVOID_HACK_LOOP +# define BEGIN { +# define END } +#else +/* + * I believe this is better, but some compiler complains.... + */ +# define BEGIN do { +# define END } while (0) +#endif + +#define Error_0(s) BEGIN \ + args = cons(mk_string((s)), NIL); \ + operator = (short)OP_ERR0; \ + return T; END + +#define Error_1(s, a) BEGIN \ + args = cons((a), NIL); \ + args = cons(mk_string((s)), args); \ + operator = (short)OP_ERR0; \ + return T; END + +/* control macros for Eval_Cycle */ +#define s_goto(a) BEGIN \ + operator = (short)(a); \ + return T; END + +#define s_save(a, b, c) ( \ + dump = cons(envir, cons((c), dump)), \ + dump = cons((b), dump), \ + dump = cons(mk_number((long)(a)), dump)) \ + + +#define s_return(a) BEGIN \ + value = (a); \ + operator = ivalue(car(dump)); \ + args = cadr(dump); \ + envir = caddr(dump); \ + code = cadddr(dump); \ + dump = cddddr(dump); \ + return T; END + +#define s_retbool(tf) s_return((tf) ? T : F) + + + +/* ========== Evaluation Cycle ========== */ + +/* operator code */ +#define OP_LOAD 0 +#define OP_T0LVL 1 +#define OP_T1LVL 2 +#define OP_READ 3 +#define OP_VALUEPRINT 4 +#define OP_EVAL 5 +#define OP_E0ARGS 6 +#define OP_E1ARGS 7 +#define OP_APPLY 8 +#define OP_DOMACRO 9 + +#define OP_LAMBDA 10 +#define OP_QUOTE 11 +#define OP_DEF0 12 +#define OP_DEF1 13 +#define OP_BEGIN 14 +#define OP_IF0 15 +#define OP_IF1 16 +#define OP_SET0 17 +#define OP_SET1 18 +#define OP_LET0 19 +#define OP_LET1 20 +#define OP_LET2 21 +#define OP_LET0AST 22 +#define OP_LET1AST 23 +#define OP_LET2AST 24 +#define OP_LET0REC 25 +#define OP_LET1REC 26 +#define OP_LET2REC 27 +#define OP_COND0 28 +#define OP_COND1 29 +#define OP_DELAY 30 +#define OP_AND0 31 +#define OP_AND1 32 +#define OP_OR0 33 +#define OP_OR1 34 +#define OP_C0STREAM 35 +#define OP_C1STREAM 36 +#define OP_0MACRO 37 +#define OP_1MACRO 38 +#define OP_CASE0 39 +#define OP_CASE1 40 +#define OP_CASE2 41 + +#define OP_PEVAL 42 +#define OP_PAPPLY 43 +#define OP_CONTINUATION 44 +#define OP_ADD 45 +#define OP_SUB 46 +#define OP_MUL 47 +#define OP_DIV 48 +#define OP_REM 49 +#define OP_CAR 50 +#define OP_CDR 51 +#define OP_CONS 52 +#define OP_SETCAR 53 +#define OP_SETCDR 54 +#define OP_NOT 55 +#define OP_BOOL 56 +#define OP_NULL 57 +#define OP_ZEROP 58 +#define OP_POSP 59 +#define OP_NEGP 60 +#define OP_NEQ 61 +#define OP_LESS 62 +#define OP_GRE 63 +#define OP_LEQ 64 +#define OP_GEQ 65 +#define OP_SYMBOL 66 +#define OP_NUMBER 67 +#define OP_STRING 68 +#define OP_PROC 69 +#define OP_PAIR 70 +#define OP_EQ 71 +#define OP_EQV 72 +#define OP_FORCE 73 +#define OP_WRITE 74 +#define OP_DISPLAY 75 +#define OP_NEWLINE 76 +#define OP_ERR0 77 +#define OP_ERR1 78 +#define OP_REVERSE 79 +#define OP_APPEND 80 +#define OP_PUT 81 +#define OP_GET 82 +#define OP_QUIT 83 +#define OP_GC 84 +#define OP_GCVERB 85 +#define OP_NEWSEGMENT 86 + +#define OP_RDSEXPR 87 +#define OP_RDLIST 88 +#define OP_RDDOT 89 +#define OP_RDQUOTE 90 +#define OP_RDQQUOTE 91 +#define OP_RDUNQUOTE 92 +#define OP_RDUQTSP 93 + +#define OP_P0LIST 94 +#define OP_P1LIST 95 + +#define OP_LIST_LENGTH 96 +#define OP_ASSQ 97 +#define OP_PRINT_WIDTH 98 +#define OP_P0_WIDTH 99 +#define OP_P1_WIDTH 100 +#define OP_GET_CLOSURE 101 +#define OP_CLOSUREP 102 +#define OP_MACROP 103 + + +static FILE *tmpfp; +static int tok; +static int print_flag; +static pointer value; +static short operator; + +pointer opexe_0(op) +register short op; +{ + register pointer x, y; + + switch (op) { + case OP_LOAD: /* load */ + if (!isstring(car(args))) { + Error_0("load -- argument is not string"); + } + if ((infp = fopen(strvalue(car(args)), "r")) == NULL) { + infp = stdin; + Error_1("Unable to open", car(args)); + } + fprintf(outfp, "loading %s", strvalue(car(args))); + s_goto(OP_T0LVL); + + case OP_T0LVL: /* top level */ + fprintf(outfp, "\n"); + dump = NIL; + envir = global_env; + s_save(OP_VALUEPRINT, NIL, NIL); + s_save(OP_T1LVL, NIL, NIL); + if (infp == stdin) + printf(prompt); + s_goto(OP_READ); + + case OP_T1LVL: /* top level */ + code = value; + s_goto(OP_EVAL); + + case OP_READ: /* read */ + tok = token(); + s_goto(OP_RDSEXPR); + + case OP_VALUEPRINT: /* print evalution result */ + print_flag = 1; + args = value; + s_save(OP_T0LVL, NIL, NIL); + s_goto(OP_P0LIST); + + case OP_EVAL: /* main part of evalution */ + if (issymbol(code)) { /* symbol */ + for (x = envir; x != NIL; x = cdr(x)) { + for (y = car(x); y != NIL; y = cdr(y)) + if (caar(y) == code) + break; + if (y != NIL) + break; + } + if (x != NIL) { + s_return(cdar(y)); + } else { + Error_1("Unbounded variable", code); + } + } else if (ispair(code)) { + if (issyntax(x = car(code))) { /* SYNTAX */ + code = cdr(code); + s_goto(syntaxnum(x)); + } else {/* first, eval top element and eval arguments */ +#ifdef USE_MACRO + s_save(OP_E0ARGS, NIL, code); +#else + s_save(OP_E1ARGS, NIL, cdr(code)); +#endif + code = car(code); + s_goto(OP_EVAL); + } + } else { + s_return(code); + } + +#ifdef USE_MACRO + case OP_E0ARGS: /* eval arguments */ + if (ismacro(value)) { /* macro expansion */ + s_save(OP_DOMACRO, NIL, NIL); + args = cons(code, NIL); + code = value; + s_goto(OP_APPLY); + } else { + code = cdr(code); + s_goto(OP_E1ARGS); + } +#endif + + case OP_E1ARGS: /* eval arguments */ + args = cons(value, args); + if (ispair(code)) { /* continue */ + s_save(OP_E1ARGS, args, cdr(code)); + code = car(code); + args = NIL; + s_goto(OP_EVAL); + } else { /* end */ + args = reverse(args); + code = car(args); + args = cdr(args); + s_goto(OP_APPLY); + } + + case OP_APPLY: /* apply 'code' to 'args' */ + if (isproc(code)) { + s_goto(procnum(code)); /* PROCEDURE */ + } else if (isclosure(code)) { /* CLOSURE */ + /* make environment */ + envir = cons(NIL, closure_env(code)); + for (x = car(closure_code(code)), y = args; + ispair(x); x = cdr(x), y = cdr(y)) { + if (y == NIL) { + Error_0("Few arguments"); + } else { + car(envir) = cons(cons(car(x), car(y)), car(envir)); + } + } + if (x == NIL) { + /*-- + * if (y != NIL) { + * Error_0("Many arguments"); + * } + */ + } else if (issymbol(x)) + car(envir) = cons(cons(x, y), car(envir)); + else { + Error_0("Syntax error in closure"); + } + code = cdr(closure_code(code)); + args = NIL; + s_goto(OP_BEGIN); + } else if (iscontinuation(code)) { /* CONTINUATION */ + dump = cont_dump(code); + s_return(args != NIL ? car(args) : NIL); + } else { + Error_0("Illegal function"); + } + +#ifdef USE_MACRO + case OP_DOMACRO: /* do macro */ + code = value; + s_goto(OP_EVAL); +#endif + + case OP_LAMBDA: /* lambda */ + s_return(mk_closure(code, envir)); + + case OP_QUOTE: /* quote */ + s_return(car(code)); + + case OP_DEF0: /* define */ + if (ispair(car(code))) { + x = caar(code); + code = cons(LAMBDA, cons(cdar(code), cdr(code))); + } else { + x = car(code); + code = cadr(code); + } + if (!issymbol(x)) { + Error_0("Variable is not symbol"); + } + s_save(OP_DEF1, NIL, x); + s_goto(OP_EVAL); + + case OP_DEF1: /* define */ + for (x = car(envir); x != NIL; x = cdr(x)) + if (caar(x) == code) + break; + if (x != NIL) + cdar(x) = value; + else + car(envir) = cons(cons(code, value), car(envir)); + s_return(code); + + case OP_SET0: /* set! */ + s_save(OP_SET1, NIL, car(code)); + code = cadr(code); + s_goto(OP_EVAL); + + case OP_SET1: /* set! */ + for (x = envir; x != NIL; x = cdr(x)) { + for (y = car(x); y != NIL; y = cdr(y)) + if (caar(y) == code) + break; + if (y != NIL) + break; + } + if (x != NIL) { + cdar(y) = value; + s_return(value); + } else { + Error_1("Unbounded variable", code); + } + + case OP_BEGIN: /* begin */ + if (!ispair(code)) { + s_return(code); + } + if (cdr(code) != NIL) { + s_save(OP_BEGIN, NIL, cdr(code)); + } + code = car(code); + s_goto(OP_EVAL); + + case OP_IF0: /* if */ + s_save(OP_IF1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + + case OP_IF1: /* if */ + if (istrue(value)) + code = car(code); + else + code = cadr(code); /* (if #f 1) ==> () because + * car(NIL) = NIL */ + s_goto(OP_EVAL); + + case OP_LET0: /* let */ + args = NIL; + value = code; + code = issymbol(car(code)) ? cadr(code) : car(code); + s_goto(OP_LET1); + + case OP_LET1: /* let (caluculate parameters) */ + args = cons(value, args); + if (ispair(code)) { /* continue */ + s_save(OP_LET1, args, cdr(code)); + code = cadar(code); + args = NIL; + s_goto(OP_EVAL); + } else { /* end */ + args = reverse(args); + code = car(args); + args = cdr(args); + s_goto(OP_LET2); + } + + case OP_LET2: /* let */ + envir = cons(NIL, envir); + for (x = issymbol(car(code)) ? cadr(code) : car(code), y = args; + y != NIL; x = cdr(x), y = cdr(y)) + car(envir) = cons(cons(caar(x), car(y)), car(envir)); + if (issymbol(car(code))) { /* named let */ + for (x = cadr(code), args = NIL; x != NIL; x = cdr(x)) + args = cons(caar(x), args); + x = mk_closure(cons(reverse(args), cddr(code)), envir); + car(envir) = cons(cons(car(code), x), car(envir)); + code = cddr(code); + args = NIL; + } else { + code = cdr(code); + args = NIL; + } + s_goto(OP_BEGIN); + + case OP_LET0AST: /* let* */ + if (car(code) == NIL) { + envir = cons(NIL, envir); + code = cdr(code); + s_goto(OP_BEGIN); + } + s_save(OP_LET1AST, cdr(code), car(code)); + code = cadaar(code); + s_goto(OP_EVAL); + + case OP_LET1AST: /* let* (make new frame) */ + envir = cons(NIL, envir); + s_goto(OP_LET2AST); + + case OP_LET2AST: /* let* (caluculate parameters) */ + car(envir) = cons(cons(caar(code), value), car(envir)); + code = cdr(code); + if (ispair(code)) { /* continue */ + s_save(OP_LET2AST, args, code); + code = cadar(code); + args = NIL; + s_goto(OP_EVAL); + } else { /* end */ + code = args; + args = NIL; + s_goto(OP_BEGIN); + } + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + } + return T; +} + + +pointer opexe_1(op) +register short op; +{ + register pointer x, y; + + switch (op) { + case OP_LET0REC: /* letrec */ + envir = cons(NIL, envir); + args = NIL; + value = code; + code = car(code); + s_goto(OP_LET1REC); + + case OP_LET1REC: /* letrec (caluculate parameters) */ + args = cons(value, args); + if (ispair(code)) { /* continue */ + s_save(OP_LET1REC, args, cdr(code)); + code = cadar(code); + args = NIL; + s_goto(OP_EVAL); + } else { /* end */ + args = reverse(args); + code = car(args); + args = cdr(args); + s_goto(OP_LET2REC); + } + + case OP_LET2REC: /* letrec */ + for (x = car(code), y = args; y != NIL; x = cdr(x), y = cdr(y)) + car(envir) = cons(cons(caar(x), car(y)), car(envir)); + code = cdr(code); + args = NIL; + s_goto(OP_BEGIN); + + case OP_COND0: /* cond */ + if (!ispair(code)) { + Error_0("Syntax error in cond"); + } + s_save(OP_COND1, NIL, code); + code = caar(code); + s_goto(OP_EVAL); + + case OP_COND1: /* cond */ + if (istrue(value)) { + if ((code = cdar(code)) == NIL) { + s_return(value); + } + s_goto(OP_BEGIN); + } else { + if ((code = cdr(code)) == NIL) { + s_return(NIL); + } else { + s_save(OP_COND1, NIL, code); + code = caar(code); + s_goto(OP_EVAL); + } + } + + case OP_DELAY: /* delay */ + x = mk_closure(cons(NIL, code), envir); + setpromise(x); + s_return(x); + + case OP_AND0: /* and */ + if (code == NIL) { + s_return(T); + } + s_save(OP_AND1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + + case OP_AND1: /* and */ + if (isfalse(value)) { + s_return(value); + } else if (code == NIL) { + s_return(value); + } else { + s_save(OP_AND1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + } + + case OP_OR0: /* or */ + if (code == NIL) { + s_return(F); + } + s_save(OP_OR1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + + case OP_OR1: /* or */ + if (istrue(value)) { + s_return(value); + } else if (code == NIL) { + s_return(value); + } else { + s_save(OP_OR1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + } + + case OP_C0STREAM: /* cons-stream */ + s_save(OP_C1STREAM, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + + case OP_C1STREAM: /* cons-stream */ + args = value; /* save value to register args for gc */ + x = mk_closure(cons(NIL, code), envir); + setpromise(x); + s_return(cons(args, x)); + +#ifdef USE_MACRO + case OP_0MACRO: /* macro */ + x = car(code); + code = cadr(code); + if (!issymbol(x)) { + Error_0("Variable is not symbol"); + } + s_save(OP_1MACRO, NIL, x); + s_goto(OP_EVAL); + + case OP_1MACRO: /* macro */ + type(value) |= T_MACRO; + for (x = car(envir); x != NIL; x = cdr(x)) + if (caar(x) == code) + break; + if (x != NIL) + cdar(x) = value; + else + car(envir) = cons(cons(code, value), car(envir)); + s_return(code); +#endif + + case OP_CASE0: /* case */ + s_save(OP_CASE1, NIL, cdr(code)); + code = car(code); + s_goto(OP_EVAL); + + case OP_CASE1: /* case */ + for (x = code; x != NIL; x = cdr(x)) { + if (!ispair(y = caar(x))) + break; + for ( ; y != NIL; y = cdr(y)) + if (eqv(car(y), value)) + break; + if (y != NIL) + break; + } + if (x != NIL) { + if (ispair(caar(x))) { + code = cdar(x); + s_goto(OP_BEGIN); + } else {/* else */ + s_save(OP_CASE2, NIL, cdar(x)); + code = caar(x); + s_goto(OP_EVAL); + } + } else { + s_return(NIL); + } + + case OP_CASE2: /* case */ + if (istrue(value)) { + s_goto(OP_BEGIN); + } else { + s_return(NIL); + } + case OP_PAPPLY: /* apply */ + code = car(args); + args = cadr(args); + s_goto(OP_APPLY); + + case OP_PEVAL: /* eval */ + code = car(args); + args = NIL; + s_goto(OP_EVAL); + + case OP_CONTINUATION: /* call-with-current-continuation */ + code = car(args); + args = cons(mk_continuation(dump), NIL); + s_goto(OP_APPLY); + + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + } + return T; +} + + +pointer opexe_2(op) +register short op; +{ + register pointer x, y; + register long v; + + switch (op) { + case OP_ADD: /* + */ + for (x = args, v = 0; x != NIL; x = cdr(x)) + v += ivalue(car(x)); + s_return(mk_number(v)); + + case OP_SUB: /* - */ + for (x = cdr(args), v = ivalue(car(args)); x != NIL; x = cdr(x)) + v -= ivalue(car(x)); + s_return(mk_number(v)); + + case OP_MUL: /* * */ + for (x = args, v = 1; x != NIL; x = cdr(x)) + v *= ivalue(car(x)); + s_return(mk_number(v)); + + case OP_DIV: /* / */ + for (x = cdr(args), v = ivalue(car(args)); x != NIL; x = cdr(x)) { + if (ivalue(car(x)) != 0) + v /= ivalue(car(x)); + else { + Error_0("Divided by zero"); + } + } + s_return(mk_number(v)); + + case OP_REM: /* remainder */ + for (x = cdr(args), v = ivalue(car(args)); x != NIL; x = cdr(x)) { + if (ivalue(car(x)) != 0) + v %= ivalue(car(x)); + else { + Error_0("Divided by zero"); + } + } + s_return(mk_number(v)); + + case OP_CAR: /* car */ + if (ispair(car(args))) { + s_return(caar(args)); + } else { + Error_0("Unable to car for non-cons cell"); + } + + case OP_CDR: /* cdr */ + if (ispair(car(args))) { + s_return(cdar(args)); + } else { + Error_0("Unable to cdr for non-cons cell"); + } + + case OP_CONS: /* cons */ + cdr(args) = cadr(args); + s_return(args); + + case OP_SETCAR: /* set-car! */ + if (ispair(car(args))) { + caar(args) = cadr(args); + s_return(car(args)); + } else { + Error_0("Unable to set-car! for non-cons cell"); + } + + case OP_SETCDR: /* set-cdr! */ + if (ispair(car(args))) { + cdar(args) = cadr(args); + s_return(car(args)); + } else { + Error_0("Unable to set-cdr! for non-cons cell"); + } + + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + } + return T; +} + + +pointer opexe_3(op) +register short op; +{ + register pointer x, y; + + switch (op) { + case OP_NOT: /* not */ + s_retbool(isfalse(car(args))); + case OP_BOOL: /* boolean? */ + s_retbool(car(args) == F || car(args) == T); + case OP_NULL: /* null? */ + s_retbool(car(args) == NIL); + case OP_ZEROP: /* zero? */ + s_retbool(ivalue(car(args)) == 0); + case OP_POSP: /* positive? */ + s_retbool(ivalue(car(args)) > 0); + case OP_NEGP: /* negative? */ + s_retbool(ivalue(car(args)) < 0); + case OP_NEQ: /* = */ + s_retbool(ivalue(car(args)) == ivalue(cadr(args))); + case OP_LESS: /* < */ + s_retbool(ivalue(car(args)) < ivalue(cadr(args))); + case OP_GRE: /* > */ + s_retbool(ivalue(car(args)) > ivalue(cadr(args))); + case OP_LEQ: /* <= */ + s_retbool(ivalue(car(args)) <= ivalue(cadr(args))); + case OP_GEQ: /* >= */ + s_retbool(ivalue(car(args)) >= ivalue(cadr(args))); + case OP_SYMBOL: /* symbol? */ + s_retbool(issymbol(car(args))); + case OP_NUMBER: /* number? */ + s_retbool(isnumber(car(args))); + case OP_STRING: /* string? */ + s_retbool(isstring(car(args))); + case OP_PROC: /* procedure? */ + /*-- + * continuation should be procedure by the example + * (call-with-current-continuation procedure?) ==> #t + * in R^3 report sec. 6.9 + */ + s_retbool(isproc(car(args)) || isclosure(car(args)) + || iscontinuation(car(args))); + case OP_PAIR: /* pair? */ + s_retbool(ispair(car(args))); + case OP_EQ: /* eq? */ + s_retbool(car(args) == cadr(args)); + case OP_EQV: /* eqv? */ + s_retbool(eqv(car(args), cadr(args))); + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + } + return T; +} + + +pointer opexe_4(op) +register short op; +{ + register pointer x, y; + + switch (op) { + case OP_FORCE: /* force */ + code = car(args); + if (ispromise(code)) { + args = NIL; + s_goto(OP_APPLY); + } else { + s_return(code); + } + + case OP_WRITE: /* write */ + print_flag = 1; + args = car(args); + s_goto(OP_P0LIST); + + case OP_DISPLAY: /* display */ + print_flag = 0; + args = car(args); + s_goto(OP_P0LIST); + + case OP_NEWLINE: /* newline */ + fprintf(outfp, "\n"); + s_return(T); + + case OP_ERR0: /* error */ + if (!isstring(car(args))) { + Error_0("error -- first argument must be string"); + } + tmpfp = outfp; + outfp = stderr; + fprintf(outfp, "Error: "); + fprintf(outfp, "%s", strvalue(car(args))); + args = cdr(args); + s_goto(OP_ERR1); + + case OP_ERR1: /* error */ + fprintf(outfp, " "); + if (args != NIL) { + s_save(OP_ERR1, cdr(args), NIL); + args = car(args); + print_flag = 1; + s_goto(OP_P0LIST); + } else { + fprintf(outfp, "\n"); + flushinput(); + outfp = tmpfp; + s_goto(OP_T0LVL); + } + + case OP_REVERSE: /* reverse */ + s_return(reverse(car(args))); + + case OP_APPEND: /* append */ + s_return(append(car(args), cadr(args))); + + case OP_PUT: /* put */ + if (!hasprop(car(args)) || !hasprop(cadr(args))) { + Error_0("Illegal use of put"); + } + for (x = symprop(car(args)), y = cadr(args); x != NIL; x = cdr(x)) + if (caar(x) == y) + break; + if (x != NIL) + cdar(x) = caddr(args); + else + symprop(car(args)) = cons(cons(y, caddr(args)), + symprop(car(args))); + s_return(T); + + case OP_GET: /* get */ + if (!hasprop(car(args)) || !hasprop(cadr(args))) { + Error_0("Illegal use of get"); + } + for (x = symprop(car(args)), y = cadr(args); x != NIL; x = cdr(x)) + if (caar(x) == y) + break; + if (x != NIL) { + s_return(cdar(x)); + } else { + s_return(NIL); + } + + case OP_QUIT: /* quit */ + return (NIL); + + case OP_GC: /* gc */ + gc(NIL, NIL); + s_return(T); + + case OP_GCVERB: /* gc-verbose */ + { int was = gc_verbose; + + gc_verbose = (car(args) != F); + s_retbool(was); + } + + case OP_NEWSEGMENT: /* new-segment */ + if (!isnumber(car(args))) { + Error_0("new-segment -- argument must be number"); + } + fprintf(outfp, "allocate %d new segments\n", + alloc_cellseg((int) ivalue(car(args)))); + s_return(T); + } +} + + +pointer opexe_5(op) +register short op; +{ + register pointer x, y; + + switch (op) { + /* ========== reading part ========== */ + case OP_RDSEXPR: + switch (tok) { + case TOK_COMMENT: + while (inchar() != '\n') + ; + tok = token(); + s_goto(OP_RDSEXPR); + case TOK_LPAREN: + tok = token(); + if (tok == TOK_RPAREN) { + s_return(NIL); + } else if (tok == TOK_DOT) { + Error_0("syntax error -- illegal dot expression"); + } else { + s_save(OP_RDLIST, NIL, NIL); + s_goto(OP_RDSEXPR); + } + case TOK_QUOTE: + s_save(OP_RDQUOTE, NIL, NIL); + tok = token(); + s_goto(OP_RDSEXPR); +#ifdef USE_QQUOTE + case TOK_BQUOTE: + s_save(OP_RDQQUOTE, NIL, NIL); + tok = token(); + s_goto(OP_RDSEXPR); + case TOK_COMMA: + s_save(OP_RDUNQUOTE, NIL, NIL); + tok = token(); + s_goto(OP_RDSEXPR); + case TOK_ATMARK: + s_save(OP_RDUQTSP, NIL, NIL); + tok = token(); + s_goto(OP_RDSEXPR); +#endif + case TOK_ATOM: + s_return(mk_atom(readstr("();\t\n "))); + case TOK_DQUOTE: + s_return(mk_string(readstrexp())); + case TOK_SHARP: + if ((x = mk_const(readstr("();\t\n "))) == NIL) { + Error_0("Undefined sharp expression"); + } else { + s_return(x); + } + default: + Error_0("syntax error -- illegal token"); + } + break; + + case OP_RDLIST: + args = cons(value, args); + tok = token(); + if (tok == TOK_COMMENT) { + while (inchar() != '\n') + ; + tok = token(); + } + if (tok == TOK_RPAREN) { + s_return(non_alloc_rev(NIL, args)); + } else if (tok == TOK_DOT) { + s_save(OP_RDDOT, args, NIL); + tok = token(); + s_goto(OP_RDSEXPR); + } else { + s_save(OP_RDLIST, args, NIL);; + s_goto(OP_RDSEXPR); + } + + case OP_RDDOT: + if (token() != TOK_RPAREN) { + Error_0("syntax error -- illegal dot expression"); + } else { + s_return(non_alloc_rev(value, args)); + } + + case OP_RDQUOTE: + s_return(cons(QUOTE, cons(value, NIL))); + +#ifdef USE_QQUOTE + case OP_RDQQUOTE: + s_return(cons(QQUOTE, cons(value, NIL))); + + case OP_RDUNQUOTE: + s_return(cons(UNQUOTE, cons(value, NIL))); + + case OP_RDUQTSP: + s_return(cons(UNQUOTESP, cons(value, NIL))); +#endif + + /* ========== printing part ========== */ + case OP_P0LIST: + if (!ispair(args)) { + printatom(args, print_flag); + s_return(T); + } else if (car(args) == QUOTE && ok_abbrev(cdr(args))) { + fprintf(outfp, "'"); + args = cadr(args); + s_goto(OP_P0LIST); + } else if (car(args) == QQUOTE && ok_abbrev(cdr(args))) { + fprintf(outfp, "`"); + args = cadr(args); + s_goto(OP_P0LIST); + } else if (car(args) == UNQUOTE && ok_abbrev(cdr(args))) { + fprintf(outfp, ","); + args = cadr(args); + s_goto(OP_P0LIST); + } else if (car(args) == UNQUOTESP && ok_abbrev(cdr(args))) { + fprintf(outfp, ",@"); + args = cadr(args); + s_goto(OP_P0LIST); + } else { + fprintf(outfp, "("); + s_save(OP_P1LIST, cdr(args), NIL); + args = car(args); + s_goto(OP_P0LIST); + } + + case OP_P1LIST: + if (ispair(args)) { + s_save(OP_P1LIST, cdr(args), NIL); + fprintf(outfp, " "); + args = car(args); + s_goto(OP_P0LIST); + } else { + if (args != NIL) { + fprintf(outfp, " . "); + printatom(args, print_flag); + } + fprintf(outfp, ")"); + s_return(T); + } + + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + + } + return T; +} + + +pointer opexe_6(op) +register short op; +{ + register pointer x, y; + register long v; + static long w; + char buffer[32]; + + switch (op) { + case OP_LIST_LENGTH: /* list-length */ /* a.k */ + for (x = car(args), v = 0; ispair(x); x = cdr(x)) + ++v; + s_return(mk_number(v)); + + case OP_ASSQ: /* assq */ /* a.k */ + x = car(args); + for (y = cadr(args); ispair(y); y = cdr(y)) { + if (!ispair(car(y))) { + Error_0("Unable to handle non pair element"); + } + if (x == caar(y)) + break; + } + if (ispair(y)) { + s_return(car(y)); + } else { + s_return(F); + } + + case OP_PRINT_WIDTH: /* print-width */ /* a.k */ + w = 0; + args = car(args); + print_flag = -1; + s_goto(OP_P0_WIDTH); + + case OP_P0_WIDTH: + if (!ispair(args)) { + w += printatom(args, print_flag); + s_return(mk_number(w)); + } else if (car(args) == QUOTE + && ok_abbrev(cdr(args))) { + ++w; + args = cadr(args); + s_goto(OP_P0_WIDTH); + } else if (car(args) == QQUOTE + && ok_abbrev(cdr(args))) { + ++w; + args = cadr(args); + s_goto(OP_P0_WIDTH); + } else if (car(args) == UNQUOTE + && ok_abbrev(cdr(args))) { + ++w; + args = cadr(args); + s_goto(OP_P0_WIDTH); + } else if (car(args) == UNQUOTESP + && ok_abbrev(cdr(args))) { + w += 2; + args = cadr(args); + s_goto(OP_P0_WIDTH); + } else { + ++w; + s_save(OP_P1_WIDTH, cdr(args), NIL); + args = car(args); + s_goto(OP_P0_WIDTH); + } + + case OP_P1_WIDTH: + if (ispair(args)) { + s_save(OP_P1_WIDTH, cdr(args), NIL); + ++w; + args = car(args); + s_goto(OP_P0_WIDTH); + } else { + if (args != NIL) + w += 3 + printatom(args, print_flag); + ++w; + s_return(mk_number(w)); + } + + case OP_GET_CLOSURE: /* get-closure-code */ /* a.k */ + args = car(args); + if (args == NIL) { + s_return(F); + } else if (isclosure(args)) { + s_return(cons(LAMBDA, closure_code(value))); +#ifdef USE_MACRO + } else if (ismacro(args)) { + s_return(cons(LAMBDA, closure_code(value))); +#endif + } else { + s_return(F); + } + case OP_CLOSUREP: /* closure? */ + /* + * Note, macro object is also a closure. + * Therefore, (closure? <#MACRO>) ==> #t + */ + if (car(args) == NIL) { + s_return(F); + } + s_retbool(isclosure(car(args))); +#ifdef USE_MACRO + case OP_MACROP: /* macro? */ + if (car(args) == NIL) { + s_return(F); + } + s_retbool(ismacro(car(args))); +#endif + default: + sprintf(strbuff, "%d is illegal operator", operator); + Error_0(strbuff); + } + return T; /* NOTREACHED */ +} + + + + +pointer (*dispatch_table[])() = { + opexe_0, /* OP_LOAD = 0, */ + opexe_0, /* OP_T0LVL, */ + opexe_0, /* OP_T1LVL, */ + opexe_0, /* OP_READ, */ + opexe_0, /* OP_VALUEPRINT, */ + opexe_0, /* OP_EVAL, */ + opexe_0, /* OP_E0ARGS, */ + opexe_0, /* OP_E1ARGS, */ + opexe_0, /* OP_APPLY, */ + opexe_0, /* OP_DOMACRO, */ + + opexe_0, /* OP_LAMBDA, */ + opexe_0, /* OP_QUOTE, */ + opexe_0, /* OP_DEF0, */ + opexe_0, /* OP_DEF1, */ + opexe_0, /* OP_BEGIN, */ + opexe_0, /* OP_IF0, */ + opexe_0, /* OP_IF1, */ + opexe_0, /* OP_SET0, */ + opexe_0, /* OP_SET1, */ + opexe_0, /* OP_LET0, */ + opexe_0, /* OP_LET1, */ + opexe_0, /* OP_LET2, */ + opexe_0, /* OP_LET0AST, */ + opexe_0, /* OP_LET1AST, */ + opexe_0, /* OP_LET2AST, */ + + opexe_1, /* OP_LET0REC, */ + opexe_1, /* OP_LET1REC, */ + opexe_1, /* OP_LETREC2, */ + opexe_1, /* OP_COND0, */ + opexe_1, /* OP_COND1, */ + opexe_1, /* OP_DELAY, */ + opexe_1, /* OP_AND0, */ + opexe_1, /* OP_AND1, */ + opexe_1, /* OP_OR0, */ + opexe_1, /* OP_OR1, */ + opexe_1, /* OP_C0STREAM, */ + opexe_1, /* OP_C1STREAM, */ + opexe_1, /* OP_0MACRO, */ + opexe_1, /* OP_1MACRO, */ + opexe_1, /* OP_CASE0, */ + opexe_1, /* OP_CASE1, */ + opexe_1, /* OP_CASE2, */ + + opexe_1, /* OP_PEVAL, */ + opexe_1, /* OP_PAPPLY, */ + opexe_1, /* OP_CONTINUATION, */ + + opexe_2, /* OP_ADD, */ + opexe_2, /* OP_SUB, */ + opexe_2, /* OP_MUL, */ + opexe_2, /* OP_DIV, */ + opexe_2, /* OP_REM, */ + opexe_2, /* OP_CAR, */ + opexe_2, /* OP_CDR, */ + opexe_2, /* OP_CONS, */ + opexe_2, /* OP_SETCAR, */ + opexe_2, /* OP_SETCDR, */ + + opexe_3, /* OP_NOT, */ + opexe_3, /* OP_BOOL, */ + opexe_3, /* OP_NULL, */ + opexe_3, /* OP_ZEROP, */ + opexe_3, /* OP_POSP, */ + opexe_3, /* OP_NEGP, */ + opexe_3, /* OP_NEQ, */ + opexe_3, /* OP_LESS, */ + opexe_3, /* OP_GRE, */ + opexe_3, /* OP_LEQ, */ + opexe_3, /* OP_GEQ, */ + opexe_3, /* OP_SYMBOL, */ + opexe_3, /* OP_NUMBER, */ + opexe_3, /* OP_STRING, */ + opexe_3, /* OP_PROC, */ + opexe_3, /* OP_PAIR, */ + opexe_3, /* OP_EQ, */ + opexe_3, /* OP_EQV, */ + + opexe_4, /* OP_FORCE, */ + opexe_4, /* OP_WRITE, */ + opexe_4, /* OP_DISPLAY, */ + opexe_4, /* OP_NEWLINE, */ + opexe_4, /* OP_ERR0, */ + opexe_4, /* OP_ERR1, */ + opexe_4, /* OP_REVERSE, */ + opexe_4, /* OP_APPEND, */ + opexe_4, /* OP_PUT, */ + opexe_4, /* OP_GET, */ + opexe_4, /* OP_QUIT, */ + opexe_4, /* OP_GC, */ + opexe_4, /* OP_GCVERB, */ + opexe_4, /* OP_NEWSEGMENT, */ + + opexe_5, /* OP_RDSEXPR, */ + opexe_5, /* OP_RDLIST, */ + opexe_5, /* OP_RDDOT, */ + opexe_5, /* OP_RDQUOTE, */ + opexe_5, /* OP_RDQQUOTE, */ + opexe_5, /* OP_RDUNQUOTE, */ + opexe_5, /* OP_RDUQTSP, */ + opexe_5, /* OP_P0LIST, */ + opexe_5, /* OP_P1LIST, */ + + opexe_6, /* OP_LIST_LENGTH, */ + opexe_6, /* OP_ASSQ, */ + opexe_6, /* OP_PRINT_WIDTH, */ + opexe_6, /* OP_P0_WIDTH, */ + opexe_6, /* OP_P1_WIDTH, */ + opexe_6, /* OP_GET_CLOSURE, */ + opexe_6, /* OP_CLOSUREP, */ +#ifdef USE_MACRO + opexe_6, /* OP_MACROP, */ +#endif + +}; + + +/* kernel of this intepreter */ +pointer Eval_Cycle(op) +register short op; +{ + + operator = op; + for (;;) + if ((*dispatch_table[operator])(operator) == NIL) + return NIL; +} + +/* ========== Initialization of internal keywords ========== */ + +mk_syntax(op, name) +unsigned short op; +char *name; +{ + pointer x; + + x = cons(mk_string(name), NIL); + type(x) = (T_SYNTAX | T_SYMBOL); + syntaxnum(x) = op; + oblist = cons(x, oblist); +} + +mk_proc(op, name) +unsigned short op; +char *name; +{ + pointer x, y; + + x = mk_symbol(name); + y = get_cell(NIL, NIL); + type(y) = (T_PROC | T_ATOM); + ivalue(y) = (long) op; + car(global_env) = cons(cons(x, y), car(global_env)); +} + + +init_vars_global() +{ + pointer x; + + /* init input/output file */ + infp = stdin; + outfp = stdout; + /* init NIL */ + type(NIL) = (T_ATOM | MARK); + car(NIL) = cdr(NIL) = NIL; + /* init T */ + type(T) = (T_ATOM | MARK); + car(T) = cdr(T) = T; + /* init F */ + type(F) = (T_ATOM | MARK); + car(F) = cdr(F) = F; + /* init global_env */ + global_env = cons(NIL, NIL); + /* init else */ + x = mk_symbol("else"); + car(global_env) = cons(cons(x, T), car(global_env)); +} + + +init_syntax() +{ + /* init syntax */ + mk_syntax(OP_LAMBDA, "lambda"); + mk_syntax(OP_QUOTE, "quote"); + mk_syntax(OP_DEF0, "define"); + mk_syntax(OP_IF0, "if"); + mk_syntax(OP_BEGIN, "begin"); + mk_syntax(OP_SET0, "set!"); + mk_syntax(OP_LET0, "let"); + mk_syntax(OP_LET0AST, "let*"); + mk_syntax(OP_LET0REC, "letrec"); + mk_syntax(OP_COND0, "cond"); + mk_syntax(OP_DELAY, "delay"); + mk_syntax(OP_AND0, "and"); + mk_syntax(OP_OR0, "or"); + mk_syntax(OP_C0STREAM, "cons-stream"); +#ifdef USE_MACRO + mk_syntax(OP_0MACRO, "macro"); +#endif + mk_syntax(OP_CASE0, "case"); +} + + +init_procs() +{ + /* init procedure */ + mk_proc(OP_PEVAL, "eval"); + mk_proc(OP_PAPPLY, "apply"); + mk_proc(OP_CONTINUATION, "call-with-current-continuation"); + mk_proc(OP_FORCE, "force"); + mk_proc(OP_CAR, "car"); + mk_proc(OP_CDR, "cdr"); + mk_proc(OP_CONS, "cons"); + mk_proc(OP_SETCAR, "set-car!"); + mk_proc(OP_SETCDR, "set-cdr!"); + mk_proc(OP_ADD, "+"); + mk_proc(OP_SUB, "-"); + mk_proc(OP_MUL, "*"); + mk_proc(OP_DIV, "/"); + mk_proc(OP_REM, "remainder"); + mk_proc(OP_NOT, "not"); + mk_proc(OP_BOOL, "boolean?"); + mk_proc(OP_SYMBOL, "symbol?"); + mk_proc(OP_NUMBER, "number?"); + mk_proc(OP_STRING, "string?"); + mk_proc(OP_PROC, "procedure?"); + mk_proc(OP_PAIR, "pair?"); + mk_proc(OP_EQV, "eqv?"); + mk_proc(OP_EQ, "eq?"); + mk_proc(OP_NULL, "null?"); + mk_proc(OP_ZEROP, "zero?"); + mk_proc(OP_POSP, "positive?"); + mk_proc(OP_NEGP, "negative?"); + mk_proc(OP_NEQ, "="); + mk_proc(OP_LESS, "<"); + mk_proc(OP_GRE, ">"); + mk_proc(OP_LEQ, "<="); + mk_proc(OP_GEQ, ">="); + mk_proc(OP_READ, "read"); + mk_proc(OP_WRITE, "write"); + mk_proc(OP_DISPLAY, "display"); + mk_proc(OP_NEWLINE, "newline"); + mk_proc(OP_LOAD, "load"); + mk_proc(OP_ERR0, "error"); + mk_proc(OP_REVERSE, "reverse"); + mk_proc(OP_APPEND, "append"); + mk_proc(OP_PUT, "put"); + mk_proc(OP_GET, "get"); + mk_proc(OP_GC, "gc"); + mk_proc(OP_GCVERB, "gc-verbose"); + mk_proc(OP_NEWSEGMENT, "new-segment"); + mk_proc(OP_LIST_LENGTH, "list-length"); /* a.k */ + mk_proc(OP_ASSQ, "assq"); /* a.k */ + mk_proc(OP_PRINT_WIDTH, "print-width"); /* a.k */ + mk_proc(OP_GET_CLOSURE, "get-closure-code"); /* a.k */ + mk_proc(OP_CLOSUREP, "closure?"); /* a.k */ +#ifdef USE_MACRO + mk_proc(OP_MACROP, "macro?"); /* a.k */ +#endif + mk_proc(OP_QUIT, "quit"); +} + + +/* initialize several globals */ +init_globals() +{ + init_vars_global(); + init_syntax(); + init_procs(); + /* intialization of global pointers to special symbols */ + LAMBDA = mk_symbol("lambda"); + QUOTE = mk_symbol("quote"); +#ifdef USE_QQUOTE + QQUOTE = mk_symbol("quasiquote"); + UNQUOTE = mk_symbol("unquote"); + UNQUOTESP = mk_symbol("unquote-splicing"); +#endif + +} + +/* ========== Error ========== */ + +FatalError(fmt, a, b, c) +char *fmt, *a, *b, *c; +{ + fprintf(stderr, "Fatal error: "); + fprintf(stderr, fmt, a, b, c); + fprintf(stderr, "\n"); + exit(1); +} + +#ifdef USE_SETJMP +Error(fmt, a, b, c) +char *fmt, *a, *b, *c; +{ + fprintf(stderr, "Error: "); + fprintf(stderr, fmt, a, b, c); + fprintf(stderr, "\n"); + flushinput(); + longjmp(error_jmp, OP_T0LVL); +} + +#endif + +/* ========== Main ========== */ + +main() +{ + short op = (short) OP_LOAD; + + printf(banner); + init_scheme(); + args = cons(mk_string(InitFile), NIL); +#ifdef USE_SETJMP + op = setjmp(error_jmp); +#endif + Eval_Cycle(op); +} + diff --git a/tests.scm b/tests.scm new file mode 100644 index 0000000..717a0be --- /dev/null +++ b/tests.scm @@ -0,0 +1,57 @@ +;;; Copyright (C) Peter McGoron 2024 +;;; This program is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, version 3 of the License. +;;; +;;; This program is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with this program. If not, see <https://www.gnu.org/licenses/>. + +;;; Test harness. +;;; Each test is a name and a function with no arguments. The function +;;; returns #t for success, #f for undefined failure, and a string for +;;; known failure. +;;; +;;; TODO: Return test results as a list. + +(define verbose? #t) + +(define run-tests + (lambda (tests) + (letrec + ((run-test + (lambda (name test) + (if verbose? + (begin + (display "running: ") + (display name) + (newline)) + #f) + (let ((result (test))) + (if (not result) + "undefined failure" + result)))) + (loop + (lambda (rest) + (if (null? rest) + #t + (let ((descr (car rest))) + (let ((return (run-test + (car descr) + (cdr descr)))) + (if (not (eq? return #t)) + return + (loop (cdr rest))))))))) + (loop tests)))) + +(load "doubly-linked-list.scm") +(display "running doubly linked list tests") +(newline) +(if (run-tests %dl:tests) + (display "doubly linked list tests: passed") + (display "doubly linked list tests: failed")) +(newline) |