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auto UsingValProvider = [content, localIdentity, bInUse, nameSid, nameLoc]( Env& e, const Term& identity, const Term& contextId, Term& result ) mutable
{
auto& dm = DiagnosticsManager::GetInstance();
if( holds_alternative< vector< TermLoc > >( content ) )
{
if( bInUse )
{
dm.emitErrorMessage( nameLoc, "recursive using expression." );
return Env::Status::NoMatch;
}
bInUse = true;
Context localContext( e.shared_from_this(), localIdentity );
auto tokProvider = lex::MakeVectorAdapter( get< vector< TermLoc > >( content ) );
auto r = make_shared< parse::Resolver >( tokProvider, localContext );
Parser p( r );
if( !p.parseExpression() )
{
// TODO: Perhaps return a poison value instead of nothing?
return Env::Status::NoMatch;
}
auto result = p.peekLastValue();
if( !result )
{
// TODO: Perhaps return a poison value instead of nothing?
return Env::Status::NoMatch;
// TODO: Perhaps return a poison value instead of nothing?
return Env::Status::NoMatch;
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auto UsingValProvider = [content, localIdentity, bInUse, nameSid, nameLoc]( Env& e, const Term& identity, const Term& contextId, Term& result ) mutable
{
auto& dm = DiagnosticsManager::GetInstance();
if( holds_alternative< vector< TermLoc > >( content ) )
{
// In case of errors, we poison the result so that code invoking
// this using expression will not emit cascading errors.
if( bInUse )
{
dm.emitErrorMessage( nameLoc, "recursive using expression." );
// We only poison the result here, not "content", since the token
// vector that it contains is currently in use. It will get poisoned
// down the line once the parent recursion level of this using
// expression finishes.
result = ValueToIRExpr( PoisonValue() );
return Env::Status::Success;
}
bInUse = true;
Context localContext( e.shared_from_this(), localIdentity );
auto tokProvider = lex::MakeVectorAdapter( get< vector< TermLoc > >( content ) );
auto r = make_shared< parse::Resolver >( tokProvider, localContext );
Parser p( r );
if( !p.parseExpression() )
{
dm.emitErrorMessage( nameLoc, "invalid expression." );
content = ValueToIRExpr( PoisonValue() );
result = get< Term >( content );
bInUse = false;
return Env::Status::Success;
}
auto result = p.peekLastValue();
if( !result )
{
dm.emitErrorMessage( nameLoc, "invalid expression." );
result = PoisonValue();
}
if( !result->isConstant() )
{
dm.emitErrorMessage( nameLoc, "using expression doesn't evaluate to a constant." );
result = PoisonValue();
}
content = ValueToIRExpr( *result );
bInUse = false;
}
result = get< Term >( content );
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