/* femtoLisp a minimal interpreter for a minimal lisp dialect this lisp dialect uses lexical scope and self-evaluating lambda. it supports 30-bit integers, symbols, conses, and full macros. it is case-sensitive. it features a simple compacting copying garbage collector. it uses a Scheme-style evaluation rule where any expression may appear in head position as long as it evaluates to a function. it uses Scheme-style varargs (dotted formal argument lists) lambdas can have only 1 body expression; use (progn ...) for multiple expressions. this is due to the closure representation (lambda args body . env) This is a fully fleshed-out lisp built up from femtoLisp. It has all the remaining features needed to be taken seriously: * circular structure can be printed and read * #. read macro for eval-when-read and correctly printing builtins * read macros for backquote * symbol character-escaping printer * vectors * exceptions * gensyms (can be usefully read back in, too) * #| multiline comments |# * generic compare function, cyclic equal * cvalues system providing C data types and a C FFI * constructor notation for nicely printing arbitrary values * strings - hash tables by Jeff Bezanson (C) 2008 Distributed under the BSD License */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "llt.h" #include "flisp.h" static char *builtin_names[] = { "quote", "cond", "if", "and", "or", "while", "lambda", "trycatch", "%apply", "setq", "progn", "eq", "atom", "not", "symbolp", "numberp", "boundp", "consp", "builtinp", "vectorp", "fixnump", "equal", "cons", "car", "cdr", "rplaca", "rplacd", "eval", "eval*", "apply", "prog1", "raise", "+", "-", "*", "/", "<", "~", "&", "!", "$", "vector", "aref", "aset", "length", "assoc", "compare", "for" }; #define N_STACK 98304 value_t Stack[N_STACK]; uint32_t SP = 0; value_t NIL, T, LAMBDA, QUOTE, IF, TRYCATCH; value_t BACKQUOTE, COMMA, COMMAAT, COMMADOT; value_t IOError, ParseError, TypeError, ArgError, UnboundError, MemoryError; value_t DivideError, BoundsError, Error, KeyError; value_t conssym, symbolsym, fixnumsym, vectorsym, builtinsym; value_t defunsym, defmacrosym, forsym, labelsym, printprettysym; value_t printwidthsym; static value_t eval_sexpr(value_t e, uint32_t penv, int tail); static value_t *alloc_words(int n); static value_t relocate(value_t v); typedef struct _readstate_t { htable_t backrefs; htable_t gensyms; struct _readstate_t *prev; } readstate_t; static readstate_t *readstate = NULL; static void free_readstate(readstate_t *rs) { htable_free(&rs->backrefs); htable_free(&rs->gensyms); } static unsigned char *fromspace; static unsigned char *tospace; static unsigned char *curheap; static unsigned char *lim; static uint32_t heapsize = 256*1024;//bytes static uint32_t *consflags; // error utilities ------------------------------------------------------------ // saved execution state for an unwind target typedef struct _ectx_t { jmp_buf buf; uint32_t sp; readstate_t *rdst; struct _ectx_t *prev; } exception_context_t; static exception_context_t *ctx = NULL; static value_t lasterror; static char lerrorbuf[512]; #define FL_TRY \ exception_context_t _ctx; int l__tr, l__ca; \ _ctx.sp=SP; _ctx.rdst=readstate; _ctx.prev=ctx; \ ctx = &_ctx; \ if (!setjmp(_ctx.buf)) \ for (l__tr=1; l__tr; l__tr=0, (void)(ctx->prev && (ctx=ctx->prev))) #define FL_CATCH \ else \ for (l__ca=1; l__ca; l__ca=0, lerrorbuf[0]='\0', lasterror=NIL) void raise(value_t e) { if (e != lasterror) { lasterror = e; lerrorbuf[0] = '\0'; // overwriting exception; clear error buf } // unwind read state while (readstate != ctx->rdst) { free_readstate(readstate); readstate = readstate->prev; } SP = ctx->sp; exception_context_t *thisctx = ctx; if (ctx->prev) // don't throw past toplevel ctx = ctx->prev; longjmp(thisctx->buf, 1); } void lerror(value_t e, char *format, ...) { va_list args; va_start(args, format); vsnprintf(lerrorbuf, sizeof(lerrorbuf), format, args); va_end(args); lasterror = e; raise(e); } void type_error(char *fname, char *expected, value_t got) { raise(listn(4, TypeError, symbol(fname), symbol(expected), got)); } void bounds_error(char *fname, value_t arr, value_t ind) { lerror(listn(3, BoundsError, arr, ind), "%s: index out of bounds", fname); } // safe cast operators -------------------------------------------------------- #define SAFECAST_OP(type,ctype,cnvt) \ ctype to##type(value_t v, char *fname) \ { \ if (is##type(v)) \ return (ctype)cnvt(v); \ type_error(fname, #type, v); \ return (ctype)0; \ } SAFECAST_OP(cons, cons_t*, ptr) SAFECAST_OP(symbol,symbol_t*,ptr) SAFECAST_OP(fixnum,fixnum_t, numval) SAFECAST_OP(cvalue,cvalue_t*,ptr) SAFECAST_OP(string,char*, cvalue_data) // symbol table --------------------------------------------------------------- symbol_t *symtab = NULL; static symbol_t *mk_symbol(char *str) { symbol_t *sym; size_t len = strlen(str); sym = (symbol_t*)malloc_aligned(sizeof(symbol_t)-sizeof(void*) + len + 1, 8); sym->left = sym->right = NULL; if (str[0] == ':') { value_t s = tagptr(sym, TAG_SYM); setc(s, s); } else { sym->binding = UNBOUND; sym->syntax = 0; } sym->type = NULL; sym->hash = memhash32(str, len)^0xAAAAAAAA; strcpy(&sym->name[0], str); return sym; } static symbol_t **symtab_lookup(symbol_t **ptree, char *str) { int x; while(*ptree != NULL) { x = strcmp(str, (*ptree)->name); if (x == 0) return ptree; if (x < 0) ptree = &(*ptree)->left; else ptree = &(*ptree)->right; } return ptree; } value_t symbol(char *str) { symbol_t **pnode; pnode = symtab_lookup(&symtab, str); if (*pnode == NULL) *pnode = mk_symbol(str); return tagptr(*pnode, TAG_SYM); } typedef struct { value_t syntax; // syntax environment entry value_t binding; // global value binding fltype_t *type; uint32_t id; } gensym_t; static uint32_t _gensym_ctr=0; // two static buffers for gensym printing so there can be two // gensym names available at a time, mostly for compare() static char gsname[2][16]; static int gsnameno=0; value_t gensym(value_t *args, uint32_t nargs) { (void)args; (void)nargs; gensym_t *gs = (gensym_t*)alloc_words(sizeof(gensym_t)/sizeof(void*)); gs->id = _gensym_ctr++; gs->binding = UNBOUND; gs->syntax = 0; gs->type = NULL; return tagptr(gs, TAG_SYM); } value_t fl_gensym() { return gensym(NULL, 0); } static char *snprintf_gensym_id(char *nbuf, size_t n, uint32_t g) { size_t i=n-1; nbuf[i--] = '\0'; do { nbuf[i--] = '0' + g%10; g/=10; } while (g && i); nbuf[i] = 'g'; return &nbuf[i]; } char *symbol_name(value_t v) { if (ismanaged(v)) { gensym_t *gs = (gensym_t*)ptr(v); gsnameno = 1-gsnameno; return snprintf_gensym_id(gsname[gsnameno], sizeof(gsname[0]), gs->id); } return ((symbol_t*)ptr(v))->name; } // conses --------------------------------------------------------------------- void gc(int mustgrow); static value_t mk_cons(void) { cons_t *c; if (curheap > lim) gc(0); c = (cons_t*)curheap; curheap += sizeof(cons_t); return tagptr(c, TAG_CONS); } static value_t *alloc_words(int n) { value_t *first; assert(n > 0); n = ALIGN(n, 2); // only allocate multiples of 2 words if ((value_t*)curheap > ((value_t*)lim)+2-n) { gc(0); while ((value_t*)curheap > ((value_t*)lim)+2-n) { gc(1); } } first = (value_t*)curheap; curheap += (n*sizeof(value_t)); return first; } // allocate n consecutive conses #define cons_reserve(n) tagptr(alloc_words((n)*2), TAG_CONS) #define cons_index(c) (((cons_t*)ptr(c))-((cons_t*)fromspace)) #define ismarked(c) bitvector_get(consflags, cons_index(c)) #define mark_cons(c) bitvector_set(consflags, cons_index(c), 1) #define unmark_cons(c) bitvector_set(consflags, cons_index(c), 0) value_t alloc_vector(size_t n, int init) { value_t *c = alloc_words(n+1); value_t v = tagptr(c, TAG_VECTOR); vector_setsize(v, n); if (init) { unsigned int i; for(i=0; i < n; i++) vector_elt(v, i) = NIL; } return v; } // cvalues -------------------------------------------------------------------- #include "cvalues.c" #include "types.c" // print ---------------------------------------------------------------------- static int isnumtok(char *tok, value_t *pval); static int symchar(char c); #include "print.c" // collector ------------------------------------------------------------------ static value_t relocate(value_t v) { value_t a, d, nc, first, *pcdr; if (iscons(v)) { // iterative implementation allows arbitrarily long cons chains pcdr = &first; do { if ((a=car_(v)) == TAG_FWD) { *pcdr = cdr_(v); return first; } *pcdr = nc = mk_cons(); d = cdr_(v); car_(v) = TAG_FWD; cdr_(v) = nc; car_(nc) = relocate(a); pcdr = &cdr_(nc); v = d; } while (iscons(v)); *pcdr = (d==NIL) ? NIL : relocate(d); return first; } uptrint_t t = tag(v); if ((t&(t-1)) == 0) return v; // tags 0,1,2,4 if (isforwarded(v)) return forwardloc(v); if (isvector(v)) { // N.B.: 0-length vectors secretly have space for a first element size_t i, newsz, sz = vector_size(v); newsz = sz; if (vector_elt(v,-1) & 0x1) newsz += vector_grow_amt(sz); nc = alloc_vector(newsz, 0); a = vector_elt(v,0); forward(v, nc); i = 0; if (sz > 0) { vector_elt(nc,0) = relocate(a); i++; for(; i < sz; i++) vector_elt(nc,i) = relocate(vector_elt(v,i)); } for(; i < newsz; i++) vector_elt(nc,i) = NIL; return nc; } else if (iscvalue(v)) { return cvalue_relocate(v); } else if (ismanaged(v)) { assert(issymbol(v)); gensym_t *gs = (gensym_t*)ptr(v); gensym_t *ng = (gensym_t*)alloc_words(sizeof(gensym_t)/sizeof(void*)); ng->id = gs->id; ng->binding = gs->binding; ng->syntax = gs->syntax; nc = tagptr(ng, TAG_SYM); forward(v, nc); if (ng->binding != UNBOUND) ng->binding = relocate(ng->binding); if (iscons(ng->syntax)) ng->syntax = relocate(ng->syntax); return nc; } return v; } value_t relocate_lispvalue(value_t v) { return relocate(v); } static void trace_globals(symbol_t *root) { while (root != NULL) { if (root->binding != UNBOUND) root->binding = relocate(root->binding); if (iscons(root->syntax)) root->syntax = relocate(root->syntax); trace_globals(root->left); root = root->right; } } static value_t special_apply_form; void gc(int mustgrow) { static int grew = 0; void *temp; uint32_t i; readstate_t *rs; curheap = tospace; lim = curheap+heapsize-sizeof(cons_t); for (i=0; i < SP; i++) Stack[i] = relocate(Stack[i]); trace_globals(symtab); relocate_typetable(); rs = readstate; while (rs) { for(i=0; i < rs->backrefs.size; i++) rs->backrefs.table[i] = (void*)relocate((value_t)rs->backrefs.table[i]); for(i=0; i < rs->gensyms.size; i++) rs->gensyms.table[i] = (void*)relocate((value_t)rs->gensyms.table[i]); rs = rs->prev; } lasterror = relocate(lasterror); special_apply_form = relocate(special_apply_form); sweep_finalizers(); #ifdef VERBOSEGC printf("GC: found %d/%d live conses\n", (curheap-tospace)/sizeof(cons_t), heapsize/sizeof(cons_t)); #endif temp = tospace; tospace = fromspace; fromspace = temp; // if we're using > 80% of the space, resize tospace so we have // more space to fill next time. if we grew tospace last time, // grow the other half of the heap this time to catch up. if (grew || ((lim-curheap) < (int)(heapsize/5)) || mustgrow) { temp = realloc_aligned(tospace, grew ? heapsize : heapsize*2, 16); if (temp == NULL) lerror(MemoryError, "out of memory"); tospace = temp; if (!grew) { heapsize*=2; } else { temp = bitvector_resize(consflags, heapsize/sizeof(cons_t), 1); if (temp == NULL) lerror(MemoryError, "out of memory"); consflags = (uint32_t*)temp; } grew = !grew; } if (curheap > lim) // all data was live gc(0); } // utils ---------------------------------------------------------------------- value_t apply(value_t f, value_t l) { PUSH(f); PUSH(l); value_t v = toplevel_eval(special_apply_form); POPN(2); return v; } value_t listn(size_t n, ...) { va_list ap; va_start(ap, n); uint32_t si = SP; size_t i; for(i=0; i < n; i++) { value_t a = va_arg(ap, value_t); PUSH(a); } cons_t *c = (cons_t*)alloc_words(n*2); cons_t *l = c; for(i=0; i < n; i++) { c->car = Stack[si++]; c->cdr = tagptr(c+1, TAG_CONS); c++; } (c-1)->cdr = NIL; POPN(n); va_end(ap); return tagptr(l, TAG_CONS); } value_t list2(value_t a, value_t b) { PUSH(a); PUSH(b); cons_t *c = (cons_t*)alloc_words(4); b = POP(); a = POP(); c[0].car = a; c[0].cdr = tagptr(c+1, TAG_CONS); c[1].car = b; c[1].cdr = NIL; return tagptr(c, TAG_CONS); } value_t fl_cons(value_t a, value_t b) { PUSH(a); PUSH(b); value_t c = mk_cons(); cdr_(c) = POP(); car_(c) = POP(); return c; } // NOTE: this is NOT an efficient operation. it is only used by the // reader; vectors should not generally be resized. // vector_grow requires at least 1 and up to 3 garbage collections! static value_t vector_grow(value_t v) { size_t s = vector_size(v); size_t d = vector_grow_amt(s); PUSH(v); // first allocate enough space to guarantee the heap will be big enough // for the new vector alloc_words(d); // setting low bit of vector's size acts as a flag to the collector // to grow this vector as it is relocated ((size_t*)ptr(Stack[SP-1]))[0] |= 0x1; gc(0); return POP(); } int isnumber(value_t v) { return (isfixnum(v) || (iscvalue(v) && valid_numtype(cv_numtype((cvalue_t*)ptr(v))))); } // read ----------------------------------------------------------------------- #include "read.c" // eval ----------------------------------------------------------------------- // return a cons element of v whose car is item static value_t assoc(value_t item, value_t v) { value_t bind; while (iscons(v)) { bind = car_(v); if (iscons(bind) && car_(bind) == item) return bind; v = cdr_(v); } return NIL; } #define eval(e) (selfevaluating(e) ? (e) : eval_sexpr((e),penv,0)) #define topeval(e, env) (selfevaluating(e) ? (e) : eval_sexpr((e),env,1)) #define tail_eval(xpr) do { SP = saveSP; \ if (selfevaluating(xpr)) { return (xpr); } \ else { e=(xpr); goto eval_top; } } while (0) static value_t do_trycatch(value_t expr, uint32_t penv) { value_t v; FL_TRY { v = eval(expr); } FL_CATCH { v = cdr_(Stack[SP-1]); if (!iscons(v)) { v = NIL; // 1-argument form } else { Stack[SP-1] = car_(v); value_t quoted = list2(QUOTE, lasterror); expr = list2(Stack[SP-1], quoted); v = eval(expr); } } return v; } /* stack setup on entry: n n+1 ... +-----+-----+-----+-----+-----+-----+-----+-----+ | LL | VAL | VAL | CLO | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+ ^ ^ | | penv SP (who knows where) where LL is the lambda list, CLO is a closed-up environment vector (which can be empty, i.e. NIL). An environment vector is just a copy of the stack from LL through CLO. There might be zero values, in which case LL is NIL. Stack[penv-1] is the size of the whole environment (as a fixnum) if tail==1, you are allowed (indeed encouraged) to overwrite this environment, otherwise you have to put any new environment on the top of the stack. */ static value_t eval_sexpr(value_t e, uint32_t penv, int tail) { value_t f, v, *pv, *argsyms, *body; cons_t *c; symbol_t *sym; uint32_t saveSP, envsz, lenv; int i, nargs=0, noeval=0; fixnum_t s, lo, hi; cvalue_t *cv; int64_t accum; eval_top: if (issymbol(e)) { sym = (symbol_t*)ptr(e); if (sym->syntax == TAG_CONST) return sym->binding; pv = &Stack[penv]; while (1) { v = *pv++; while (iscons(v)) { if (car_(v)==e) return *pv; v = cdr_(v); pv++; } if (v == e) return *pv; // dotted list if (v != NIL) pv++; if (*pv == NIL) break; pv = &vector_elt(*pv, 0); } if ((v = sym->binding) == UNBOUND) raise(list2(UnboundError, e)); return v; } if (SP >= (N_STACK-64)) lerror(MemoryError, "eval: stack overflow"); saveSP = SP; v = car_(e); PUSH(cdr_(e)); if (selfevaluating(v)) f=v; else if (issymbol(v) && (f=((symbol_t*)ptr(v))->syntax)) { // handle special syntax forms if (isspecial(f)) goto apply_special; else if (f == TAG_CONST) f = ((symbol_t*)ptr(v))->binding; else noeval = 2; } else f = eval(v); v = Stack[saveSP]; if (isbuiltinish(f)) { // handle builtin function // evaluate argument list, placing arguments on stack while (iscons(v)) { v = eval(car_(v)); PUSH(v); v = Stack[saveSP] = cdr_(Stack[saveSP]); } apply_builtin: nargs = SP - saveSP - 1; apply_special: switch (uintval(f)) { // special forms case F_QUOTE: if (!iscons(Stack[saveSP])) lerror(ArgError, "quote: expected argument"); v = car_(Stack[saveSP]); break; case F_SETQ: e = car(Stack[saveSP]); v = eval(car(cdr_(Stack[saveSP]))); pv = &Stack[penv]; while (1) { f = *pv++; while (iscons(f)) { if (car_(f)==e) { *pv = v; SP = saveSP; return v; } f = cdr_(f); pv++; } if (f == e) { *pv = v; SP = saveSP; return v; } if (f != NIL) pv++; if (*pv == NIL) break; pv = &vector_elt(*pv, 0); } sym = tosymbol(e, "setq"); if (sym->syntax != TAG_CONST) sym->binding = v; break; case F_LAMBDA: // build a closure (lambda args body . env) if (Stack[penv] != NIL) { // save temporary environment to the heap lenv = penv; envsz = numval(Stack[penv-1]); pv = alloc_words(envsz + 1); PUSH(tagptr(pv, TAG_VECTOR)); pv[0] = fixnum(envsz); pv++; while (envsz--) *pv++ = Stack[penv++]; // environment representation changed; install // the new representation so everybody can see it Stack[lenv] = NIL; Stack[lenv+1] = Stack[SP-1]; } else { PUSH(Stack[penv+1]); // env has already been captured; share } c = (cons_t*)ptr(v=cons_reserve(3)); c->car = LAMBDA; c->cdr = tagptr(c+1, TAG_CONS); c++; c->car = car(Stack[saveSP]); //argsyms c->cdr = tagptr(c+1, TAG_CONS); c++; c->car = car(cdr_(Stack[saveSP])); //body c->cdr = Stack[SP-1]; //env break; case F_IF: v = car(Stack[saveSP]); if (eval(v) != NIL) v = car(cdr_(Stack[saveSP])); else v = car(cdr(cdr_(Stack[saveSP]))); tail_eval(v); break; case F_COND: pv = &Stack[saveSP]; v = NIL; while (iscons(*pv)) { c = tocons(car_(*pv), "cond"); v = eval(c->car); if (v != NIL) { *pv = cdr_(car_(*pv)); // evaluate body forms if (iscons(*pv)) { while (iscons(cdr_(*pv))) { v = eval(car_(*pv)); *pv = cdr_(*pv); } tail_eval(car_(*pv)); } break; } *pv = cdr_(*pv); } break; case F_AND: pv = &Stack[saveSP]; v = T; if (iscons(*pv)) { while (iscons(cdr_(*pv))) { if ((v=eval(car_(*pv))) == NIL) { SP = saveSP; return NIL; } *pv = cdr_(*pv); } tail_eval(car_(*pv)); } break; case F_OR: pv = &Stack[saveSP]; v = NIL; if (iscons(*pv)) { while (iscons(cdr_(*pv))) { if ((v=eval(car_(*pv))) != NIL) { SP = saveSP; return v; } *pv = cdr_(*pv); } tail_eval(car_(*pv)); } break; case F_WHILE: PUSH(cdr(Stack[saveSP])); body = &Stack[SP-1]; PUSH(*body); Stack[saveSP] = car_(Stack[saveSP]); value_t *cond = &Stack[saveSP]; PUSH(NIL); pv = &Stack[SP-1]; while (eval(*cond) != NIL) { *body = Stack[SP-2]; while (iscons(*body)) { *pv = eval(car_(*body)); *body = cdr_(*body); } } v = *pv; break; case F_PROGN: // return last arg pv = &Stack[saveSP]; if (iscons(*pv)) { while (iscons(cdr_(*pv))) { (void)eval(car_(*pv)); *pv = cdr_(*pv); } tail_eval(car_(*pv)); } v = NIL; break; case F_TRYCATCH: v = do_trycatch(car(Stack[saveSP]), penv); break; // ordinary functions case F_BOUNDP: argcount("boundp", nargs, 1); sym = tosymbol(Stack[SP-1], "boundp"); v = (sym->binding == UNBOUND) ? NIL : T; break; case F_EQ: argcount("eq", nargs, 2); v = ((Stack[SP-2] == Stack[SP-1]) ? T : NIL); break; case F_CONS: argcount("cons", nargs, 2); if (curheap > lim) gc(0); c = (cons_t*)curheap; curheap += sizeof(cons_t); c->car = Stack[SP-2]; c->cdr = Stack[SP-1]; v = tagptr(c, TAG_CONS); break; case F_CAR: argcount("car", nargs, 1); v = car(Stack[SP-1]); break; case F_CDR: argcount("cdr", nargs, 1); v = cdr(Stack[SP-1]); break; case F_RPLACA: argcount("rplaca", nargs, 2); car(v=Stack[SP-2]) = Stack[SP-1]; break; case F_RPLACD: argcount("rplacd", nargs, 2); cdr(v=Stack[SP-2]) = Stack[SP-1]; break; case F_VECTOR: v = alloc_vector(nargs, 0); memcpy(&vector_elt(v,0), &Stack[saveSP+1], nargs*sizeof(value_t)); break; case F_LENGTH: argcount("length", nargs, 1); if (isvector(Stack[SP-1])) { v = fixnum(vector_size(Stack[SP-1])); break; } else if (iscvalue(Stack[SP-1])) { cv = (cvalue_t*)ptr(Stack[SP-1]); v = cv_type(cv); if (iscons(v) && car_(v) == arraysym) { v = size_wrap(cvalue_arraylen(Stack[SP-1])); break; } else if (v == bytesym) { v = fixnum(1); break; } else if (v == wcharsym) { v = fixnum(u8_charlen(*(uint32_t*)cv_data(cv))); break; } } else if (Stack[SP-1] == NIL) { v = fixnum(0); break; } else if (iscons(Stack[SP-1])) { v = fixnum(llength(Stack[SP-1])); break; } type_error("length", "sequence", Stack[SP-1]); break; case F_AREF: argcount("aref", nargs, 2); v = Stack[SP-2]; i = tofixnum(Stack[SP-1], "aref"); if (isvector(v)) { if ((unsigned)i >= vector_size(v)) bounds_error("aref", v, Stack[SP-1]); v = vector_elt(v, i); } else { // TODO other sequence types? type_error("aref", "sequence", v); } break; case F_ASET: argcount("aset", nargs, 3); e = Stack[SP-3]; i = tofixnum(Stack[SP-2], "aset"); if (isvector(e)) { if ((unsigned)i >= vector_size(e)) bounds_error("aref", v, Stack[SP-1]); vector_elt(e, i) = (v=Stack[SP-1]); } else { type_error("aset", "sequence", e); } break; case F_ATOM: argcount("atom", nargs, 1); v = ((!iscons(Stack[SP-1])) ? T : NIL); break; case F_CONSP: argcount("consp", nargs, 1); v = (iscons(Stack[SP-1]) ? T : NIL); break; case F_SYMBOLP: argcount("symbolp", nargs, 1); v = ((issymbol(Stack[SP-1])) ? T : NIL); break; case F_NUMBERP: argcount("numberp", nargs, 1); v = ((isfixnum(Stack[SP-1]) || (iscvalue(Stack[SP-1]) && valid_numtype(cv_numtype((cvalue_t*)ptr(Stack[SP-1]))) )) ? T : NIL); break; case F_FIXNUMP: argcount("fixnump", nargs, 1); v = (isfixnum(Stack[SP-1]) ? T : NIL); break; case F_BUILTINP: argcount("builtinp", nargs, 1); v = (isbuiltinish(Stack[SP-1]) ? T : NIL); break; case F_VECTORP: argcount("vectorp", nargs, 1); v = ((isvector(Stack[SP-1])) ? T : NIL); break; case F_NOT: argcount("not", nargs, 1); v = ((Stack[SP-1] == NIL) ? T : NIL); break; case F_ADD: s = 0; for (i=saveSP+1; i < (int)SP; i++) { if (isfixnum(Stack[i])) { s += numval(Stack[i]); if (!fits_fixnum(s)) { i++; goto add_ovf; } } else { add_ovf: v = fl_add_any(&Stack[i], SP-i, s); SP = saveSP; return v; } } v = fixnum(s); break; case F_SUB: if (nargs < 1) lerror(ArgError, "-: too few arguments"); i = saveSP+1; if (nargs == 1) { if (isfixnum(Stack[i])) v = fixnum(-numval(Stack[i])); else v = fl_neg(Stack[i]); break; } if (nargs == 2) { if (bothfixnums(Stack[i], Stack[i+1])) { s = numval(Stack[i]) - numval(Stack[i+1]); if (fits_fixnum(s)) { v = fixnum(s); break; } Stack[i+1] = fixnum(-numval(Stack[i+1])); } else { Stack[i+1] = fl_neg(Stack[i+1]); } } else { Stack[i+1] = fl_neg(fl_add_any(&Stack[i+1], nargs-1, 0)); } v = fl_add_any(&Stack[i], 2, 0); break; case F_MUL: accum = 1; for (i=saveSP+1; i < (int)SP; i++) { if (isfixnum(Stack[i])) { accum *= numval(Stack[i]); } else { v = fl_mul_any(&Stack[i], SP-i, accum); SP = saveSP; return v; } } if (fits_fixnum(accum)) v = fixnum(accum); else v = return_from_int64(accum); break; case F_DIV: if (nargs < 1) lerror(ArgError, "/: too few arguments"); i = saveSP+1; if (nargs == 1) { v = fl_div2(fixnum(1), Stack[i]); } else { if (nargs > 2) Stack[i+1] = fl_mul_any(&Stack[i+1], nargs-1, 1); v = fl_div2(Stack[i], Stack[i+1]); } break; case F_BNOT: argcount("~", nargs, 1); if (isfixnum(Stack[SP-1])) v = fixnum(~numval(Stack[SP-1])); else v = fl_bitwise_not(Stack[SP-1]); break; case F_BAND: argcount("&", nargs, 2); if (bothfixnums(Stack[SP-1], Stack[SP-2])) v = Stack[SP-1] & Stack[SP-2]; else v = fl_bitwise_op(Stack[SP-2], Stack[SP-1], 0, "&"); break; case F_BOR: argcount("!", nargs, 2); if (bothfixnums(Stack[SP-1], Stack[SP-2])) v = Stack[SP-1] | Stack[SP-2]; else v = fl_bitwise_op(Stack[SP-2], Stack[SP-1], 1, "!"); break; case F_BXOR: argcount("$", nargs, 2); if (bothfixnums(Stack[SP-1], Stack[SP-2])) v = fixnum(numval(Stack[SP-1]) ^ numval(Stack[SP-2])); else v = fl_bitwise_op(Stack[SP-2], Stack[SP-1], 2, "$"); break; case F_COMPARE: argcount("compare", nargs, 2); v = compare(Stack[SP-2], Stack[SP-1]); break; case F_LT: argcount("<", nargs, 2); if (bothfixnums(Stack[SP-2], Stack[SP-1])) { v = (numval(Stack[SP-2]) < numval(Stack[SP-1])) ? T : NIL; } else { v = (numval(compare(Stack[SP-2], Stack[SP-1])) < 0) ? T : NIL; } break; case F_EQUAL: argcount("equal", nargs, 2); if (eq_comparable(Stack[SP-2],Stack[SP-1])) { v = (Stack[SP-2] == Stack[SP-1]) ? T : NIL; } else { v = (numval(compare(Stack[SP-2], Stack[SP-1]))==0) ? T : NIL; } break; case F_EVAL: argcount("eval", nargs, 1); v = Stack[SP-1]; if (selfevaluating(v)) { SP=saveSP; return v; } if (tail) { Stack[penv-1] = fixnum(2); Stack[penv] = NIL; Stack[penv+1] = NIL; SP = penv + 2; e=v; goto eval_top; } else { PUSH(fixnum(2)); PUSH(NIL); PUSH(NIL); v = eval_sexpr(v, SP-2, 1); } break; case F_EVALSTAR: argcount("eval*", nargs, 1); e = Stack[SP-1]; if (selfevaluating(e)) { SP=saveSP; return e; } SP = penv+2; goto eval_top; case F_RAISE: argcount("raise", nargs, 1); raise(Stack[SP-1]); break; case F_PROG1: // return first arg if (nargs < 1) lerror(ArgError, "prog1: too few arguments"); v = Stack[saveSP+1]; break; case F_ASSOC: argcount("assoc", nargs, 2); v = assoc(Stack[SP-2], Stack[SP-1]); break; case F_FOR: argcount("for", nargs, 3); lo = tofixnum(Stack[SP-3], "for"); hi = tofixnum(Stack[SP-2], "for"); f = Stack[SP-1]; v = car(cdr(f)); if (!iscons(v) || !iscons(cdr_(cdr_(f))) || cdr_(v) != NIL) lerror(ArgError, "for: expected 1 argument lambda"); f = cdr_(f); PUSH(f); // save function cdr SP += 4; // make space Stack[SP-4] = fixnum(3); // env size Stack[SP-1] = cdr_(cdr_(f)); // cloenv v = NIL; for(s=lo; s <= hi; s++) { f = Stack[SP-5]; Stack[SP-3] = car_(f); // lambda list Stack[SP-2] = fixnum(s); // argument value v = car_(cdr_(f)); if (!selfevaluating(v)) v = eval_sexpr(v, SP-3, 0); } break; case F_SPECIAL_APPLY: v = Stack[saveSP-4]; f = Stack[saveSP-5]; PUSH(f); PUSH(v); nargs = 2; // falls through!! case F_APPLY: argcount("apply", nargs, 2); v = Stack[saveSP] = Stack[SP-1]; // second arg is new arglist f = Stack[SP-2]; // first arg is new function POPN(2); // pop apply's args if (isbuiltinish(f)) { assert(!isspecial(f)); // unpack arglist onto the stack while (iscons(v)) { PUSH(car_(v)); v = cdr_(v); } goto apply_builtin; } noeval = 1; goto apply_lambda; default: // function pointer tagged as a builtin v = ((builtin_t)ptr(f))(&Stack[saveSP+1], nargs); } SP = saveSP; return v; } apply_lambda: if (iscons(f)) { // apply lambda expression f = cdr_(f); PUSH(f); PUSH(car(f)); // arglist argsyms = &Stack[SP-1]; // build a calling environment for the lambda // the environment is the argument binds on top of the captured // environment if (noeval) { while (iscons(v)) { // bind args if (!iscons(*argsyms)) { if (*argsyms == NIL) lerror(ArgError, "apply: too many arguments"); break; } PUSH(car_(v)); *argsyms = cdr_(*argsyms); v = cdr_(v); } if (*argsyms != NIL && issymbol(*argsyms)) PUSH(v); } else { while (iscons(v)) { // bind args if (!iscons(*argsyms)) { if (*argsyms == NIL) lerror(ArgError, "apply: too many arguments"); break; } v = eval(car_(v)); PUSH(v); *argsyms = cdr_(*argsyms); v = Stack[saveSP] = cdr_(Stack[saveSP]); } if (*argsyms != NIL && issymbol(*argsyms)) { PUSH(Stack[saveSP]); // this version uses collective allocation. about 7-10% // faster for lists with > 2 elements, but uses more // stack space i = SP; while (iscons(Stack[saveSP])) { v = car_(Stack[saveSP]); v = eval(v); PUSH(v); Stack[saveSP] = cdr_(Stack[saveSP]); } nargs = SP-i; if (nargs) { Stack[i-1] = cons_reserve(nargs); c = (cons_t*)ptr(Stack[i-1]); for(; i < (int)SP; i++) { c->car = Stack[i]; c->cdr = tagptr(c+1, TAG_CONS); c++; } (c-1)->cdr = Stack[saveSP]; POPN(nargs); } } } if (iscons(*argsyms)) { lerror(ArgError, "apply: too few arguments"); } f = cdr_(Stack[saveSP+1]); e = car(f); if (selfevaluating(e)) { SP=saveSP; return(e); } PUSH(cdr_(f)); // add closed environment *argsyms = car_(Stack[saveSP+1]); // put lambda list if (noeval == 2) { // macro: evaluate body in lambda environment Stack[saveSP+1] = fixnum(SP-saveSP-2); e = eval_sexpr(e, saveSP+2, 1); SP = saveSP; if (selfevaluating(e)) return(e); noeval = 0; // macro: evaluate expansion in calling environment goto eval_top; } else { envsz = SP - saveSP - 2; if (tail) { noeval = 0; // ok to overwrite environment for(i=0; i < (int)envsz; i++) Stack[penv+i] = Stack[saveSP+2+i]; SP = penv+envsz; Stack[penv-1] = fixnum(envsz); goto eval_top; } else { Stack[saveSP+1] = fixnum(envsz); v = eval_sexpr(e, saveSP+2, 1); SP = saveSP; return v; } } // not reached } type_error("apply", "function", f); return NIL; } // initialization ------------------------------------------------------------- extern void builtins_init(); extern void comparehash_init(); static char *EXEDIR; void assign_global_builtins(builtinspec_t *b) { while (b->name != NULL) { set(symbol(b->name), cbuiltin(b->name, b->fptr)); b++; } } void lisp_init(void) { int i; llt_init(); fromspace = malloc_aligned(heapsize, 16); tospace = malloc_aligned(heapsize, 16); curheap = fromspace; lim = curheap+heapsize-sizeof(cons_t); consflags = bitvector_new(heapsize/sizeof(cons_t), 1); htable_new(&printconses, 32); comparehash_init(); NIL = symbol("nil"); setc(NIL, NIL); T = symbol("T"); setc(T, T); LAMBDA = symbol("lambda"); QUOTE = symbol("quote"); TRYCATCH = symbol("trycatch"); BACKQUOTE = symbol("backquote"); COMMA = symbol("*comma*"); COMMAAT = symbol("*comma-at*"); COMMADOT = symbol("*comma-dot*"); IOError = symbol("io-error"); ParseError = symbol("parse-error"); TypeError = symbol("type-error"); ArgError = symbol("arg-error"); UnboundError = symbol("unbound-error"); KeyError = symbol("key-error"); MemoryError = symbol("memory-error"); BoundsError = symbol("bounds-error"); DivideError = symbol("divide-error"); Error = symbol("error"); conssym = symbol("cons"); symbolsym = symbol("symbol"); fixnumsym = symbol("fixnum"); vectorsym = symbol("vector"); builtinsym = symbol("builtin"); defunsym = symbol("defun"); defmacrosym = symbol("defmacro"); forsym = symbol("for"); labelsym = symbol("label"); set(printprettysym=symbol("*print-pretty*"), T); set(printwidthsym=symbol("*print-width*"), fixnum(SCR_WIDTH)); lasterror = NIL; lerrorbuf[0] = '\0'; special_apply_form = fl_cons(builtin(F_SPECIAL_APPLY), NIL); i = 0; while (isspecial(builtin(i))) { if (i != F_SPECIAL_APPLY) ((symbol_t*)ptr(symbol(builtin_names[i])))->syntax = builtin(i); i++; } for (; i < N_BUILTINS; i++) { setc(symbol(builtin_names[i]), builtin(i)); } #ifdef LINUX set(symbol("os.name"), symbol("linux")); #elif defined(WIN32) || defined(WIN64) set(symbol("os.name"), symbol("win32")); #elif defined(MACOSX) set(symbol("os.name"), symbol("macos")); #else set(symbol("os.name"), symbol("unknown")); #endif cvalues_init(); set(symbol("gensym"), cbuiltin("gensym", gensym)); set(symbol("hash"), cbuiltin("hash", fl_hash)); char buf[1024]; char *exename = get_exename(buf, sizeof(buf)); if (exename != NULL) { path_to_dirname(exename); EXEDIR = strdup(exename); setc(symbol("*install-dir*"), cvalue_static_cstring(EXEDIR)); } builtins_init(); } // repl ----------------------------------------------------------------------- value_t toplevel_eval(value_t expr) { value_t v; uint32_t saveSP = SP; PUSH(fixnum(2)); PUSH(NIL); PUSH(NIL); v = topeval(expr, SP-2); SP = saveSP; return v; } static void print_toplevel_exception() { if (iscons(lasterror) && car_(lasterror) == TypeError && llength(lasterror) == 4) { ios_printf(ios_stderr, "type-error: "); print(ios_stderr, car_(cdr_(lasterror)), 1); ios_printf(ios_stderr, ": expected "); print(ios_stderr, car_(cdr_(cdr_(lasterror))), 1); ios_printf(ios_stderr, ", got "); print(ios_stderr, car_(cdr_(cdr_(cdr_(lasterror)))), 0); } else if (iscons(lasterror) && car_(lasterror) == UnboundError && iscons(cdr_(lasterror))) { ios_printf(ios_stderr, "unbound-error: eval: variable %s has no value", (symbol_name(car_(cdr_(lasterror))))); } else if (iscons(lasterror) && car_(lasterror) == Error) { value_t v = cdr_(lasterror); ios_printf(ios_stderr, "error: "); while (iscons(v)) { print(ios_stderr, car_(v), 1); v = cdr_(v); } } else { if (lasterror != NIL) { if (!lerrorbuf[0]) ios_printf(ios_stderr, "*** Unhandled exception: "); print(ios_stderr, lasterror, 0); if (lerrorbuf[0]) ios_printf(ios_stderr, ": "); } } if (lerrorbuf[0]) ios_printf(ios_stderr, "%s", lerrorbuf); } value_t load_file(char *fname) { value_t volatile e, v=NIL; ios_t fi; ios_t * volatile f; fname = strdup(fname); f = &fi; f = ios_file(f, fname, 0, 0); if (f == NULL) lerror(IOError, "file \"%s\" not found", fname); FL_TRY { while (1) { e = read_sexpr(f); //print(ios_stdout,e,0); ios_putc('\n', ios_stdout); if (ios_eof(f)) break; v = toplevel_eval(e); } } FL_CATCH { ios_close(f); size_t msglen = strlen(lerrorbuf); snprintf(&lerrorbuf[msglen], sizeof(lerrorbuf)-msglen, "\nin file \"%s\"", fname); lerrorbuf[sizeof(lerrorbuf)-1] = '\0'; free(fname); raise(lasterror); } free(fname); ios_close(f); return v; } static value_t argv_list(int argc, char *argv[]) { int i; PUSH(NIL); if (argc > 1) { argc--; argv++; } for(i=argc-1; i >= 0; i--) Stack[SP-1] = fl_cons(cvalue_static_cstring(argv[i]), Stack[SP-1]); return POP(); } int locale_is_utf8; int main(int argc, char *argv[]) { value_t v; locale_is_utf8 = u8_is_locale_utf8(setlocale(LC_ALL, "")); lisp_init(); set(symbol("argv"), argv_list(argc, argv)); FL_TRY { // install toplevel exception handler } FL_CATCH { print_toplevel_exception(); lerrorbuf[0] = '\0'; lasterror = NIL; ios_puts("\n\n", ios_stderr); if (argc > 1) return 1; else goto repl; } load_file("system.lsp"); if (argc > 1) { load_file(argv[1]); return 0; } printf("; _ \n"); printf("; |_ _ _ |_ _ | . _ _\n"); printf("; | (-||||_(_)|__|_)|_)\n"); printf(";-------------------|----------------------------------------------------------\n\n"); repl: while (1) { ios_puts("> ", ios_stdout); ios_flush(ios_stdout); FL_TRY { v = read_sexpr(ios_stdin); } FL_CATCH { ios_purge(ios_stdin); raise(lasterror); } if (ios_eof(ios_stdin)) break; print(ios_stdout, v=toplevel_eval(v), 0); set(symbol("that"), v); ios_puts("\n\n", ios_stdout); } ios_putc('\n', ios_stdout); return 0; }