void YacasPatternPredicateBase::SetPatternVariables(LispEnvironment& aEnvironment,
LispPtr* arguments)
{
const std::size_t n = iVariables.size();
for (std::size_t i = 0; i < n; ++i)
aEnvironment.NewLocal(iVariables[i],arguments[i]);
}
void InternalApplyPure(LispPtr& oper,LispPtr& args2,LispPtr& aResult,LispEnvironment& aEnvironment)
{
LispPtr * chk1 = oper->SubList();
if (!chk1)
throw LispErrInvalidArg();
LispPtr oper2((*chk1)->Nixed());
if (!oper2)
throw LispErrInvalidArg();
LispPtr body(oper2->Nixed());
if (!body)
throw LispErrInvalidArg();
LispPtr * chk2 = oper2->SubList();
if (!chk2 || !*chk2)
throw LispErrInvalidArg();
oper2 = ((*chk2)->Nixed());
LispLocalFrame frame(aEnvironment,false);
while (!!oper2) {
if (!args2)
throw LispErrInvalidArg();
const LispString* var = oper2->String();
if (!var)
throw LispErrInvalidArg();
LispPtr newly(args2->Copy());
aEnvironment.NewLocal(var,newly);
oper2 = (oper2->Nixed());
args2 = (args2->Nixed());
}
if (args2)
throw LispErrInvalidArg();
aEnvironment.iEvaluator->Eval(aEnvironment, aResult, body);
}
void BranchingUserFunction::Evaluate(LispPtr& aResult,LispEnvironment& aEnvironment,
LispPtr& aArguments)
{
const LispInt arity = Arity();
LispInt i;
if (Traced()) {
LispPtr tr(LispSubList::New(aArguments));
TraceShowEnter(aEnvironment, tr);
tr = nullptr;
}
LispIterator iter(aArguments);
++iter;
// unrollable arguments
std::unique_ptr<LispPtr[]> arguments(arity == 0 ? nullptr : new LispPtr[arity]);
// Walk over all arguments, evaluating them as necessary
for (i = 0; i < arity; i++, ++iter) {
if (!iter.getObj())
throw LispErrWrongNumberOfArgs();
if (iParameters[i].iHold) {
arguments[i] = iter.getObj()->Copy();
} else {
//Check(iter.getObj(), KLispErrWrongNumberOfArgs); // checked above
InternalEval(aEnvironment, arguments[i], *iter);
}
}
if (Traced()) {
LispIterator iter(aArguments);
for (i = 0; i < arity; i++)
TraceShowArg(aEnvironment, *++iter, arguments[i]);
}
// declare a new local stack.
LispLocalFrame frame(aEnvironment, Fenced());
// define the local variables.
for (i = 0; i < arity; i++) {
const LispString* variable = iParameters[i].iParameter;
// set the variable to the new value
aEnvironment.NewLocal(variable, arguments[i]);
}
// walk the rules database, returning the evaluated result if the
// predicate is true.
const std::size_t nrRules = iRules.size();
UserStackInformation &st = aEnvironment.iEvaluator->StackInformation();
for (std::size_t i = 0; i < nrRules; i++) {
BranchRuleBase* thisRule = iRules[i];
assert(thisRule);
st.iRulePrecedence = thisRule->Precedence();
bool matches = thisRule->Matches(aEnvironment, arguments.get());
if (matches) {
st.iSide = 1;
InternalEval(aEnvironment, aResult, thisRule->Body());
goto FINISH;
}
// If rules got inserted, walk back
while (thisRule != iRules[i] && i > 0)
i--;
}
// No predicate was true: return a new expression with the evaluated
// arguments.
{
LispPtr full(aArguments->Copy());
if (arity == 0) {
full->Nixed() = nullptr;
} else {
full->Nixed() = arguments[0];
for (i = 0; i < arity - 1; i++)
arguments[i]->Nixed() = arguments[i + 1];
}
aResult = LispSubList::New(full);
}
FINISH:
if (Traced()) {
LispPtr tr(LispSubList::New(aArguments));
TraceShowLeave(aEnvironment, aResult, tr);
tr = nullptr;
}
}