/**
* get symbol's name
*
* @param[in] sem is the semantic table where symbols and structures are define
* @param[in] s the Symbol to return the label of
* @returns cstring surface of the first label in the definition
*
* <b>Examples (from test suite):</b>
* @snippet spec/semtable_spec.h testSemTableGetName
*/
char *_sem_get_name(SemTable *sem,SemanticID s) {
if (s.id == 0) {
if (s.context == SYS_CONTEXT) {
switch (s.semtype) {
case SEM_TYPE_STRUCTURE: return "NULL_STRUCTURE";
case SEM_TYPE_SYMBOL: return "NULL_SYMBOL";
case SEM_TYPE_PROCESS: return "NULL_PROCESS";
case SEM_TYPE_RECEPTOR: return "SYS_RECEPTOR";
default: raise_error("bad semtype");
}
}
else {
raise_error("unexpected semantic NULL id!");
}
}
T *def = _sem_get_def(sem,s);
char *n = NULL;
if (def) {
int path[] ={DefLabelIdx,1,TREE_PATH_TERMINATOR};
T *t = _t_get(def,path);
if (!t) raise_error("missing label!");
n = (char *)_t_surface(t);
}
return n;
}
/**
* implements the INTERPOLATE_FROM_MATCH process
*
* replaces the interpolation tree with the matched sub-parts from a semtrex match results tree
*
* @param[in] t interpolation tree to be scanned for INTERPOLATE_SYMBOL nodes
* @param[in] match_results SEMTREX_MATCH_RESULTS tree
* @param[in] match_tree original tree that was matched (needed to grab the data to interpolate)
* @todo what to do if match has sibs??
*/
void _p_interpolate_from_match(T *t,T *match_results,T *match_tree) {
if (semeq(_t_symbol(t),INTERPOLATE_SYMBOL)) {
Symbol s = *(Symbol *)_t_surface(t);
T *m = _t_get_match(match_results,s);
if (!m) {
raise_error0("expected to have match!");
}
int *path = (int *)_t_surface(_t_child(m,2));
int sibs = *(int*)_t_surface(_t_child(m,3));
T *x = _t_get(match_tree,path);
if (!x) {
raise_error0("expecting to get a value from match!!");
}
_t_morph(t,x);
}
DO_KIDS(t,_p_interpolate_from_match(_t_child(t,i),match_results,match_tree));
}
/**
* take one step in the execution state machine given a run-tree context
*
* a run_tree is expected to have a code tree as the first child, parameters as the second,
* and optionally an error handling routine as the third child.
*
* @param[in] processes context of defined processes
* @param[in] pointer to context pointer
* @returns the next state that will be called for the context
*/
Error _p_step(Defs *defs, R **contextP) {
R *context = *contextP;
switch(context->state) {
case noReductionErr:
case Block:
case Send:
raise_error0("whoa, virtual states can't be executed!"); // shouldn't be calling step if Done or noErr or Block or Send
break;
case Pop:
// if this was the successful reduction by an error handler
// move the value to the 1st child
if (context->err) {
T *t = _t_detach_by_idx(context->run_tree,3);
if (t) {
_t_replace(context->run_tree,1,t);
context->err = noReductionErr;
}
}
// if this is top caller on the stack then we are completely done
if (!context->caller) {
context->state = Done;
break;
}
else {
// otherwise pop the context
R *ctx = context;
context = context->caller; // set the new context
if (!ctx->err) {
// get results of the run_tree
T *np = _t_detach_by_idx(ctx->run_tree,1);
_t_replace(context->parent,context->idx,np); // replace the process call node with the result
rt_cur_child(np) = RUN_TREE_EVALUATED;
context->node_pointer = np;
context->state = Eval; // or possible ascend??
}
else context->state = ctx->err;
// cleanup
_t_free(ctx->run_tree);
free(ctx);
context->callee = 0;
*contextP = context;
}
break;
case Eval:
{
T *np = context->node_pointer;
if (!np) {
raise_error0("Whoa! Null node pointer");
}
Process s = _t_symbol(np);
if (semeq(s,PARAM_REF)) {
T *param = _t_get(context->run_tree,(int *)_t_surface(np));
if (!param) {
raise_error0("request for non-existent param");
}
context->node_pointer = np = _t_rclone(param);
_t_replace(context->parent, context->idx,np);
s = _t_symbol(np);
}
// @todo what if the replaced parameter is itself a PARAM_REF tree ??
// if this node is not a process, i.e. it's data, then we are done descending
// and it will be the result so ascend
if (!is_process(s)) {
context->state = Ascend;
}
else {
int c = _t_children(np);
if (c == rt_cur_child(np) || semeq(s,QUOTE)) {
// if the current child == the child count this means
// all the children have been processed, so we can evaluate this process
// if the process is QUOTE that's a special case and we evaluate it
// immediately without descending.
if (!is_sys_process(s)) {
// if it's user defined process then we check the signature and then make
// a new run-tree run that process
Error e = __p_check_signature(defs,s,np);
if (e) context->state = e;
else {
T *run_tree = __p_make_run_tree(defs->processes,s,np);
context->state = Pushed;
*contextP = __p_make_context(run_tree,context);
}
}
else {
// if it's a sys process we can just reduce it in and then ascend
// or move to the error handling state
Error e = __p_reduce_sys_proc(context,s,np);
context->state = e ? e : Ascend;
}
}
else if(c) {
//descend and increment the current child we're working on!
context->state = Descend;
}
else {
raise_error0("whoa! brain fart!");
}
}
}
break;
case Ascend:
rt_cur_child(context->node_pointer) = RUN_TREE_EVALUATED;
context->node_pointer = context->parent;
context->parent = _t_parent(context->node_pointer);
if (!context->parent || context->parent == context->run_tree) {
context->idx = 1;
}
else context->idx = rt_cur_child(context->parent);
if (context->node_pointer == context->run_tree)
context->state = Pop;
else
context->state = Eval;
break;
case Descend:
context->parent = context->node_pointer;
context->idx = ++rt_cur_child(context->node_pointer);
context->node_pointer = _t_child(context->node_pointer,context->idx);
context->state = Eval;
break;
default:
context->err = context->state;
if (_t_children(context->run_tree) <= 2) {
// no error handler so just return the error
context->state = Pop;
}
else {
// the first parameter to the error code is always a reduction error
// which gets added on as the 4th child of the run tree when the
// error happens.
T *ps = _t_newr(context->run_tree,PARAMS);
//@todo: fix this so we don't actually use an error value that
// then has to be translated into a symbol, but rather so that we
// can programatically calculate the symbol.
Symbol se;
switch(context->state) {
case tooFewParamsReductionErr: se=TOO_FEW_PARAMS_ERR;break;
case tooManyParamsReductionErr: se=TOO_MANY_PARAMS_ERR;break;
case signatureMismatchReductionErr: se=SIGNATURE_MISMATCH_ERR;break;
case notProcessReductionError: se=NOT_A_PROCESS_ERR;break;
case notInSignalContextReductionError: se=NOT_IN_SIGNAL_CONTEXT_ERR;
case divideByZeroReductionErr: se=ZERO_DIVIDE_ERR;break;
case incompatibleTypeReductionErr: se=INCOMPATIBLE_TYPE_ERR;break;
case raiseReductionErr:
se = *(Symbol *)_t_surface(_t_child(context->node_pointer,1));
break;
default: raise_error("unknown reduction error: %d",context->state);
}
T *err = __t_new(ps,se,0,0,sizeof(rT));
int *path = _t_get_path(context->node_pointer);
_t_new(err,ERROR_LOCATION,path,sizeof(int)*(_t_path_depth(path)+1));
free(path);
// switch the node_pointer to the top of the error handling routine
context->node_pointer = _t_child(context->run_tree,3);
context->idx = 3;
context->parent = context->run_tree;
context->state = Eval;
}
}
return context->state;
}
/**
* bootstrap the ceptr system
*
* starts up the vmhost and wakes up receptors that should be running in it.
*
* @TODO check the compository to verify our version of the vmhost
*
*/
void _a_boot(char *dir_path) {
// check if the storage directory exists
struct stat st = {0};
if (stat(dir_path, &st) == -1) {
// if no directory we are firing up an initial instance, so
// create directory
mkdir(dir_path,0700);
// instantiate a VMHost object
G_vm = _v_new();
// create the basic receptors that all VMHosts have
_v_instantiate_builtins(G_vm);
}
else {
char fn[1000];
void *buffer;
// unserialize the semtable base tree
SemTable *sem = _sem_new();
T *t = __a_unserializet(dir_path,SEM_FN);
sem->stores[0].definitions = t;
// restore definitions to the correct store slots
T *paths = __a_unserializet(dir_path,PATHS_FN);
int i = 0;
int c = _t_children(paths);
for(i=1;i<=c;i++) {
T *p = _t_child(paths,i);
if (semeq(RECEPTOR_PATH,_t_symbol(p))) {
T *x = _t_get(t,(int *)_t_surface(p));
sem->stores[i-1].definitions = x;
}
}
_t_free(paths);
sem->contexts = c+1;
// unserialize all of the vmhost's instantiated receptors and other instances
__a_vmfn(fn,dir_path);
buffer = readFile(fn,0);
Receptor *r = _r_unserialize(sem,buffer);
G_vm = __v_init(r,sem);
free(buffer);
// unserialize other vmhost state data
S *s;
__a_vm_state_fn(fn,dir_path);
s = readFile(fn,0);
H h = _m_unserialize(s);
free(s);
H hars; hars.m=h.m; hars.a = _m_child(h,1); // first child is ACTIVE_RECEPTORS
H har; har.m=h.m;
int j = _m_children(hars);
for (i=1;i<=j;i++) {
har.a = _m_child(hars,i);
if(!semeq(_m_symbol(har),RECEPTOR_XADDR)) raise_error("expecting RECEPTOR_XADDR!");
_v_activate(G_vm,*(Xaddr *)_m_surface(har));
}
_m_free(h);
}
G_vm->dir = dir_path;
// _a_check_vm_host_version_on_the_compository();
_v_start_vmhost(G_vm);
}