/* assign -- bind a list of values to a list of variables */
static List *assign(Tree *varform, Tree *valueform0, Binding *binding0) {
Ref(List *, result, NULL);
Ref(Tree *, valueform, valueform0);
Ref(Binding *, binding, binding0);
Ref(List *, vars, glom(varform, binding, FALSE));
if (vars == NULL)
fail("es:assign", "null variable name");
Ref(List *, values, glom(valueform, binding, TRUE));
result = values;
for (; vars != NULL; vars = vars->next) {
List *value;
Ref(char *, name, getstr(vars->term));
if (values == NULL)
value = NULL;
else if (vars->next == NULL || values->next == NULL) {
value = values;
values = NULL;
} else {
value = mklist(values->term, NULL);
values = values->next;
}
vardef(name, binding, value);
RefEnd(name);
}
RefEnd4(values, vars, binding, valueform);
RefReturn(result);
}
extern List *extractmatches(List *subjects, List *patterns, StrList *quotes) {
List **prevp;
List *subject;
Ref(List *, result, NULL);
prevp = &result;
gcdisable();
for (subject = subjects; subject != NULL; subject = subject->next) {
List *pattern;
StrList *quote;
for (pattern = patterns, quote = quotes;
pattern != NULL;
pattern = pattern->next, quote = quote->next) {
List *match;
char *pat = getstr(pattern->term);
match = extractsinglematch(getstr(subject->term),
pat, quote->str, NULL);
if (match != NULL) {
/* match is returned backwards, so reverse it */
match = reverse(match);
for (*prevp = match; match != NULL; match = *prevp)
prevp = &match->next;
break;
}
}
}
gcenable();
RefReturn(result);
}
/* bindargs -- bind an argument list to the parameters of a lambda */
extern Binding *bindargs(Tree *params, List *args, Binding *binding) {
if (params == NULL)
return mkbinding("*", args, binding);
gcdisable();
for (; params != NULL; params = params->u[1].p) {
Tree *param;
List *value;
assert(params->kind == nList);
param = params->u[0].p;
assert(param->kind == nWord || param->kind == nQword);
if (args == NULL)
value = NULL;
else if (params->u[1].p == NULL || args->next == NULL) {
value = args;
args = NULL;
} else {
value = mklist(args->term, NULL);
args = args->next;
}
binding = mkbinding(param->u[0].s, value, binding);
}
Ref(Binding *, result, binding);
gcenable();
RefReturn(result);
}
extern Term *mkterm(char *str, Closure *closure) {
gcdisable();
Ref(Term *, term, gcnew(Term));
term->str = str;
term->closure = closure;
gcenable();
RefReturn(term);
}
/* listify -- turn an argc/argv vector into a list */
extern List *listify(int argc, char **argv) {
Ref(List *, list, NULL);
while (argc > 0) {
Term *term = mkterm(argv[--argc], NULL);
list = mklist(term, list);
}
RefReturn(list);
}
extern StrList *mkstrlist(char *str, StrList *next) {
gcdisable(0);
assert(str != NULL);
Ref(StrList *, list, gcnew(StrList));
list->str = str;
list->next = next;
gcenable();
RefReturn(list);
}
extern List *mklist(Term *term, List *next) {
gcdisable(0);
assert(term != NULL);
Ref(List *, list, gcnew(List));
list->term = term;
list->next = next;
gcenable();
RefReturn(list);
}
static Var *mkvar(List *defn) {
Ref(Var *, var, NULL);
Ref(List *, lp, defn);
var = gcnew(Var);
var->env = NULL;
var->defn = lp;
var->flags = hasbindings(lp) ? var_hasbindings : 0;
RefEnd(lp);
RefReturn(var);
}
/* local -- build, recursively, one layer of local assignment */
static List *local(Tree *defn, Tree *body0,
Binding *bindings0, int evalflags) {
Ref(List *, result, NULL);
Ref(Tree *, body, body0);
Ref(Binding *, bindings, bindings0);
Ref(Binding *, dynamic,
reversebindings(letbindings(defn, NULL, bindings, evalflags)));
result = localbind(dynamic, bindings, body, evalflags);
RefEnd3(dynamic, bindings, body);
RefReturn(result);
}
extern Term *termcat(Term *t1, Term *t2) {
if (t1 == NULL)
return t2;
if (t2 == NULL)
return t1;
Ref(Term *, term, mkstr(NULL));
Ref(char *, str1, getstr(t1));
Ref(char *, str2, getstr(t2));
term->str = str("%s%s", str1, str2);
RefEnd2(str2, str1);
RefReturn(term);
}
/* extractpattern -- Like matchpattern, but returns matches */
static List *extractpattern(Tree *subjectform0, Tree *patternform0,
Binding *binding) {
List *pattern;
StrList *quote = NULL;
Ref(List *, result, NULL);
Ref(Binding *, bp, binding);
Ref(Tree *, patternform, patternform0);
Ref(List *, subject, glom(subjectform0, bp, TRUE));
pattern = glom2(patternform, bp, "e);
result = (List *) extractmatches(subject, pattern, quote);
RefEnd3(subject, patternform, bp);
RefReturn(result);
}
static List *callsettor(char *name, List *defn) {
Push p;
List *settor;
if (specialvar(name) || (settor = varlookup2("set-", name, NULL)) == NULL)
return defn;
Ref(List *, lp, defn);
Ref(List *, fn, settor);
varpush(&p, "0", mklist(mkstr(name), NULL));
lp = listcopy(eval(append(fn, lp), NULL, 0));
varpop(&p);
RefEnd(fn);
RefReturn(lp);
}
/* safereverse -- reverse a list, non-destructively */
extern List *safereverse(List *list) {
List *lp;
if (list == NULL)
return NULL;
if (list->next == NULL)
return list;
gcdisable(0);
for (lp = NULL; list != NULL; list = list->next)
lp = mklist(list->term, lp);
Ref(List *, result, lp);
gcenable();
RefReturn(result);
}
/* localbind -- recursively convert a Bindings list into dynamic binding */
static List *localbind(Binding *dynamic0, Binding *lexical0,
Tree *body0, int evalflags) {
if (dynamic0 == NULL)
return walk(body0, lexical0, evalflags);
else {
Push p;
Ref(List *, result, NULL);
Ref(Tree *, body, body0);
Ref(Binding *, dynamic, dynamic0);
Ref(Binding *, lexical, lexical0);
varpush(&p, dynamic->name, dynamic->defn);
result = localbind(dynamic->next, lexical, body, evalflags);
varpop(&p);
RefEnd3(lexical, dynamic, body);
RefReturn(result);
}
}
/* letbindings -- create a new Binding containing let-bound variables */
static Binding *letbindings(Tree *defn0, Binding *outer0,
Binding *context0, int evalflags) {
Ref(Binding *, binding, outer0);
Ref(Binding *, context, context0);
Ref(Tree *, defn, defn0);
for (; defn != NULL; defn = defn->u[1].p) {
assert(defn->kind == nList);
if (defn->u[0].p == NULL)
continue;
Ref(Tree *, assign, defn->u[0].p);
assert(assign->kind == nAssign);
Ref(List *, vars, glom(assign->u[0].p, context, FALSE));
Ref(List *, values, glom(assign->u[1].p, context, TRUE));
if (vars == NULL)
fail("es:let", "null variable name");
for (; vars != NULL; vars = vars->next) {
List *value;
Ref(char *, name, getstr(vars->term));
if (values == NULL)
value = NULL;
else if (vars->next == NULL || values->next == NULL) {
value = values;
values = NULL;
} else {
value = mklist(values->term, NULL);
values = values->next;
}
binding = mkbinding(name, value, binding);
RefEnd(name);
}
RefEnd3(values, vars, assign);
}
RefEnd2(defn, context);
RefReturn(binding);
}
/* append -- merge two lists, non-destructively */
extern List *append(List *head, List *tail) {
List *lp, **prevp;
#if 0 /* if you want this optimization, rewrite listcopy */
if (tail0 == NULL)
return head0;
#endif
Ref(List *, hp, head);
Ref(List *, tp, tail);
gcdisable(40 * sizeof (List));
head = hp;
tail = tp;
RefEnd2(tp, hp);
for (prevp = &lp; head != NULL; head = head->next) {
List *np = mklist(head->term, NULL);
*prevp = np;
prevp = &np->next;
}
*prevp = tail;
Ref(List *, result, lp);
gcenable();
RefReturn(result);
}
/* listvars -- return a list of all the (dynamic) variables */
extern List *listvars(Boolean internal) {
Ref(List *, varlist, NULL);
dictforall(vars, internal ? listinternal : listexternal, &varlist);
varlist = sortlist(varlist);
RefReturn(varlist);
}
/* expandhome -- do tilde expansion by calling fn %home */
static char *expandhome(char *s, StrList *qp) {
int c;
size_t slash;
List *fn = varlookup("fn-%home", NULL);
assert(*s == '~');
assert(qp->str == UNQUOTED || *qp->str == 'r');
if (fn == NULL)
return s;
for (slash = 1; (c = s[slash]) != '/' && c != '\0'; slash++)
;
Ref(char *, string, s);
Ref(StrList *, quote, qp);
Ref(List *, list, NULL);
RefAdd(fn);
if (slash > 1)
list = mklist(mkstr(gcndup(s + 1, slash - 1)), NULL);
RefRemove(fn);
list = eval(append(fn, list), NULL, 0);
if (list != NULL) {
if (list->next != NULL)
fail("es:expandhome", "%%home returned more than one value");
Ref(char *, home, getstr(list->term));
if (c == '\0') {
string = home;
quote->str = QUOTED;
} else {
char *q;
size_t pathlen = strlen(string);
size_t homelen = strlen(home);
size_t len = pathlen - slash + homelen;
s = gcalloc(len + 1, &StringTag);
memcpy(s, home, homelen);
memcpy(&s[homelen], &string[slash], pathlen - slash);
s[len] = '\0';
string = s;
q = quote->str;
if (q == UNQUOTED) {
q = gcalloc(len + 1, &StringTag);
memset(q, 'q', homelen);
memset(&q[homelen], 'r', pathlen - slash);
q[len] = '\0';
} else if (strchr(q, 'r') == NULL)
q = QUOTED;
else {
q = gcalloc(len + 1, &StringTag);
memset(q, 'q', homelen);
memcpy(&q[homelen], "e->str[slash], pathlen - slash);
q[len] = '\0';
}
quote->str = q;
}
RefEnd(home);
}
RefEnd2(list, quote);
RefReturn(string);
}
/* forloop -- evaluate a for loop */
static List *forloop(Tree *defn0, Tree *body0,
Binding *binding, int evalflags) {
static List MULTIPLE = { NULL, NULL };
Ref(List *, result, true);
Ref(Binding *, outer, binding);
Ref(Binding *, looping, NULL);
Ref(Tree *, body, body0);
Ref(Tree *, defn, defn0);
for (; defn != NULL; defn = defn->u[1].p) {
assert(defn->kind == nList);
if (defn->u[0].p == NULL)
continue;
Ref(Tree *, assign, defn->u[0].p);
assert(assign->kind == nAssign);
Ref(List *, vars, glom(assign->u[0].p, outer, FALSE));
Ref(List *, list, glom(assign->u[1].p, outer, TRUE));
if (vars == NULL)
fail("es:for", "null variable name");
for (; vars != NULL; vars = vars->next) {
char *var = getstr(vars->term);
looping = mkbinding(var, list, looping);
list = &MULTIPLE;
}
RefEnd3(list, vars, assign);
SIGCHK();
}
looping = reversebindings(looping);
RefEnd(defn);
ExceptionHandler
for (;;) {
Boolean allnull = TRUE;
Ref(Binding *, bp, outer);
Ref(Binding *, lp, looping);
Ref(Binding *, sequence, NULL);
for (; lp != NULL; lp = lp->next) {
Ref(List *, value, NULL);
if (lp->defn != &MULTIPLE)
sequence = lp;
assert(sequence != NULL);
if (sequence->defn != NULL) {
value = mklist(sequence->defn->term,
NULL);
sequence->defn = sequence->defn->next;
allnull = FALSE;
}
bp = mkbinding(lp->name, value, bp);
RefEnd(value);
}
RefEnd2(sequence, lp);
if (allnull) {
RefPop(bp);
break;
}
result = walk(body, bp, evalflags & eval_exitonfalse);
RefEnd(bp);
SIGCHK();
}
CatchException (e)
if (!termeq(e->term, "break"))
throw(e);
result = e->next;
EndExceptionHandler
RefEnd3(body, looping, outer);
RefReturn(result);
}
/* eval -- evaluate a list, producing a list */
extern List *eval(List *list0, Binding *binding0, int flags) {
Closure *volatile cp;
List *fn;
if (++evaldepth >= maxevaldepth)
fail("es:eval", "max-eval-depth exceeded");
Ref(List *, list, list0);
Ref(Binding *, binding, binding0);
Ref(char *, funcname, NULL);
restart:
if (list == NULL) {
RefPop3(funcname, binding, list);
--evaldepth;
return true;
}
assert(list->term != NULL);
if ((cp = getclosure(list->term)) != NULL) {
switch (cp->tree->kind) {
case nPrim:
assert(cp->binding == NULL);
list = prim(cp->tree->u[0].s, list->next, binding, flags);
break;
case nThunk:
list = walk(cp->tree->u[0].p, cp->binding, flags);
break;
case nLambda:
ExceptionHandler
Push p;
Ref(Tree *, tree, cp->tree);
Ref(Binding *, context,
bindargs(tree->u[0].p,
list->next,
cp->binding));
if (funcname != NULL)
varpush(&p, "0",
mklist(mkterm(funcname,
NULL),
NULL));
list = walk(tree->u[1].p, context, flags);
if (funcname != NULL)
varpop(&p);
RefEnd2(context, tree);
CatchException (e)
if (termeq(e->term, "return")) {
list = e->next;
goto done;
}
throw(e);
EndExceptionHandler
break;
case nList: {
list = glom(cp->tree, cp->binding, TRUE);
list = append(list, list->next);
goto restart;
}
default:
panic("eval: bad closure node kind %d",
cp->tree->kind);
}
goto done;
}
/* the logic here is duplicated in $&whatis */
Ref(char *, name, getstr(list->term));
fn = varlookup2("fn-", name, binding);
if (fn != NULL) {
funcname = name;
list = append(fn, list->next);
RefPop(name);
goto restart;
}
if (isabsolute(name)) {
char *error = checkexecutable(name);
if (error != NULL)
fail("$&whatis", "%s: %s", name, error);
list = forkexec(name, list, flags & eval_inchild);
RefPop(name);
goto done;
}
RefEnd(name);
fn = pathsearch(list->term);
if (fn != NULL && fn->next == NULL
&& (cp = getclosure(fn->term)) == NULL) {
char *name = getstr(fn->term);
list = forkexec(name, list, flags & eval_inchild);
goto done;
}
list = append(fn, list->next);
goto restart;
done:
--evaldepth;
if ((flags & eval_exitonfalse) && !istrue(list))
exit(exitstatus(list));
RefEnd2(funcname, binding);
RefReturn(list);
}
