Established intern bug is in getting, not setting; improved exceptions.

This commit is contained in:
Simon Brooke 2026-02-28 15:15:42 +00:00
parent 54f6f023c6
commit a1c377bc7c
9 changed files with 241 additions and 97 deletions

View file

@ -248,7 +248,7 @@ lisp_nlambda( struct stack_frame *frame, struct cons_pointer frame_pointer,
* Evaluate a lambda or nlambda expression.
*/
struct cons_pointer
eval_lambda( struct cons_space_object cell, struct stack_frame *frame,
eval_lambda( struct cons_space_object *cell, struct stack_frame *frame,
struct cons_pointer frame_pointer, struct cons_pointer env ) {
struct cons_pointer result = NIL;
#ifdef DEBUG
@ -257,8 +257,8 @@ eval_lambda( struct cons_space_object cell, struct stack_frame *frame,
#endif
struct cons_pointer new_env = env;
struct cons_pointer names = cell.payload.lambda.args;
struct cons_pointer body = cell.payload.lambda.body;
struct cons_pointer names = cell->payload.lambda.args;
struct cons_pointer body = cell->payload.lambda.body;
if ( consp( names ) ) {
/* if `names` is a list, bind successive items from that list
@ -328,6 +328,57 @@ eval_lambda( struct cons_space_object cell, struct stack_frame *frame,
return result;
}
/**
* if `r` is an exception, and it doesn't have a location, fix up its location from
* the name associated with this fn_pointer, if any.
*/
struct cons_pointer maybe_fixup_exception_location( struct cons_pointer r,
struct cons_pointer
fn_pointer ) {
struct cons_pointer result = r;
if ( exceptionp( result ) && (functionp( fn_pointer) || specialp(fn_pointer))) {
struct cons_space_object *fn_cell = &pointer2cell( fn_pointer );
struct cons_pointer payload =
pointer2cell( result ).payload.exception.payload;
/* TODO: should name_key also be a privileged keyword? */
struct cons_pointer name_key =
c_string_to_lisp_keyword( L"name" );
switch ( get_tag_value( payload ) ) {
case NILTV:
case CONSTV:
case HASHTV:
{
if ( nilp( c_assoc( privileged_keyword_location ,
payload ) )) {
pointer2cell( result ).payload.exception.payload =
set( privileged_keyword_location,
c_assoc( name_key,
fn_cell->payload.function.meta ),
payload );
}
}
break;
default:
pointer2cell( result ).payload.exception.payload =
make_cons(
make_cons( privileged_keyword_location,
c_assoc( name_key,
fn_cell->payload.function.meta ) ),
make_cons(
make_cons( privileged_keyword_payload,
payload ) ,
NIL ));
}
dec_ref( name_key);
}
return result;
}
/**
* Internal guts of apply.
@ -348,10 +399,10 @@ c_apply( struct stack_frame *frame, struct cons_pointer frame_pointer,
if ( exceptionp( fn_pointer ) ) {
result = fn_pointer;
} else {
struct cons_space_object fn_cell = pointer2cell( fn_pointer );
struct cons_space_object *fn_cell = &pointer2cell( fn_pointer );
struct cons_pointer args = c_cdr( frame->arg[0] );
switch ( fn_cell.tag.value ) {
switch ( get_tag_value( fn_pointer ) ) {
case EXCEPTIONTV:
/* just pass exceptions straight back */
result = fn_pointer;
@ -369,10 +420,15 @@ c_apply( struct stack_frame *frame, struct cons_pointer frame_pointer,
struct stack_frame *next =
get_stack_frame( next_pointer );
result =
( *fn_cell.payload.function.executable ) ( next,
next_pointer,
env );
result = maybe_fixup_exception_location( ( *
( fn_cell->
payload.
function.
executable ) )
( next,
next_pointer,
env ),
fn_pointer );
dec_ref( next_pointer );
}
}
@ -406,18 +462,14 @@ c_apply( struct stack_frame *frame, struct cons_pointer frame_pointer,
}
break;
case VECTORPOINTTV:
switch ( pointer_to_vso( fn_pointer )->header.tag.value ) {
case HASHTV:
/* \todo: if arg[0] is a CONS, treat it as a path */
result = c_assoc( eval_form( frame,
frame_pointer,
c_car( c_cdr
( frame->arg
[0] ) ), env ),
fn_pointer );
break;
}
case HASHTV:
/* \todo: if arg[0] is a CONS, treat it as a path */
result = c_assoc( eval_form( frame,
frame_pointer,
c_car( c_cdr
( frame->arg
[0] ) ), env ),
fn_pointer );
break;
case NLAMBDATV:
@ -441,14 +493,16 @@ c_apply( struct stack_frame *frame, struct cons_pointer frame_pointer,
{
struct cons_pointer next_pointer =
make_special_frame( frame_pointer, args, env );
inc_ref( next_pointer );
// inc_ref( next_pointer );
if ( exceptionp( next_pointer ) ) {
result = next_pointer;
} else {
result =
( *fn_cell.payload.special.
executable ) ( get_stack_frame( next_pointer ),
next_pointer, env );
result = maybe_fixup_exception_location( ( *
( fn_cell->
payload.
special.
executable ) )
( get_stack_frame( next_pointer ), next_pointer, env ), fn_pointer );
debug_print( L"Special form returning: ", DEBUG_EVAL );
debug_print_object( result, DEBUG_EVAL );
debug_println( DEBUG_EVAL );
@ -464,13 +518,16 @@ c_apply( struct stack_frame *frame, struct cons_pointer frame_pointer,
memset( buffer, '\0', bs );
swprintf( buffer, bs,
L"Unexpected cell with tag %d (%4.4s) in function position",
fn_cell.tag.value, &fn_cell.tag.bytes[0] );
fn_cell->tag.value, &( fn_cell->tag.bytes[0] ) );
struct cons_pointer message =
c_string_to_lisp_string( buffer );
free( buffer );
result = throw_exception( message, frame_pointer );
result =
throw_exception( c_string_to_lisp_symbol( L"apply" ),
message, frame_pointer );
}
}
}
debug_print( L"c_apply: returning: ", DEBUG_EVAL );
@ -507,9 +564,9 @@ lisp_eval( struct stack_frame *frame, struct cons_pointer frame_pointer,
debug_dump_object( frame_pointer, DEBUG_EVAL );
struct cons_pointer result = frame->arg[0];
struct cons_space_object cell = pointer2cell( frame->arg[0] );
struct cons_space_object *cell = &pointer2cell( frame->arg[0] );
switch ( cell.tag.value ) {
switch ( cell->tag.value ) {
case CONSTV:
result = c_apply( frame, frame_pointer, env );
break;
@ -522,7 +579,9 @@ lisp_eval( struct stack_frame *frame, struct cons_pointer frame_pointer,
make_cons( c_string_to_lisp_string
( L"Attempt to take value of unbound symbol." ),
frame->arg[0] );
result = throw_exception( message, frame_pointer );
result =
throw_exception( c_string_to_lisp_symbol( L"eval" ),
message, frame_pointer );
} else {
result = c_assoc( canonical, env );
inc_ref( result );
@ -623,7 +682,8 @@ lisp_set( struct stack_frame *frame, struct cons_pointer frame_pointer,
result = frame->arg[1];
} else {
result =
throw_exception( make_cons
throw_exception( c_string_to_lisp_symbol( L"set" ),
make_cons
( c_string_to_lisp_string
( L"The first argument to `set` is not a symbol: " ),
make_cons( frame->arg[0], NIL ) ),
@ -662,7 +722,8 @@ lisp_set_shriek( struct stack_frame *frame, struct cons_pointer frame_pointer,
result = val;
} else {
result =
throw_exception( make_cons
throw_exception( c_string_to_lisp_symbol( L"set!" ),
make_cons
( c_string_to_lisp_string
( L"The first argument to `set!` is not a symbol: " ),
make_cons( frame->arg[0], NIL ) ),
@ -734,24 +795,25 @@ struct cons_pointer
lisp_car( struct stack_frame *frame, struct cons_pointer frame_pointer,
struct cons_pointer env ) {
struct cons_pointer result = NIL;
struct cons_space_object cell = pointer2cell( frame->arg[0] );
struct cons_space_object *cell = &pointer2cell( frame->arg[0] );
switch ( cell.tag.value ) {
switch ( cell->tag.value ) {
case CONSTV:
result = cell.payload.cons.car;
result = cell->payload.cons.car;
break;
case NILTV:
break;
case READTV:
result =
make_string( url_fgetwc( cell.payload.stream.stream ), NIL );
make_string( url_fgetwc( cell->payload.stream.stream ), NIL );
break;
case STRINGTV:
result = make_string( cell.payload.string.character, NIL );
result = make_string( cell->payload.string.character, NIL );
break;
default:
result =
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"car" ),
c_string_to_lisp_string
( L"Attempt to take CAR of non sequence" ),
frame_pointer );
}
@ -778,24 +840,25 @@ struct cons_pointer
lisp_cdr( struct stack_frame *frame, struct cons_pointer frame_pointer,
struct cons_pointer env ) {
struct cons_pointer result = NIL;
struct cons_space_object cell = pointer2cell( frame->arg[0] );
struct cons_space_object *cell = &pointer2cell( frame->arg[0] );
switch ( cell.tag.value ) {
switch ( cell->tag.value ) {
case CONSTV:
result = cell.payload.cons.cdr;
result = cell->payload.cons.cdr;
break;
case NILTV:
break;
case READTV:
url_fgetwc( cell.payload.stream.stream );
url_fgetwc( cell->payload.stream.stream );
result = frame->arg[0];
break;
case STRINGTV:
result = cell.payload.string.cdr;
result = cell->payload.string.cdr;
break;
default:
result =
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"cdr" ),
c_string_to_lisp_string
( L"Attempt to take CDR of non sequence" ),
frame_pointer );
}
@ -856,7 +919,8 @@ lisp_internedp( struct stack_frame *frame, struct cons_pointer frame_pointer,
struct cons_pointer old = result;
struct cons_space_object *cell = &( pointer2cell( result ) );
result =
throw_exception( cell->payload.exception.payload, frame_pointer );
throw_exception( c_string_to_lisp_symbol( L"interned?" ),
cell->payload.exception.payload, frame_pointer );
dec_ref( old );
}
@ -1213,7 +1277,8 @@ struct cons_pointer eval_cond_clause( struct cons_pointer clause,
#endif
}
} else {
result = throw_exception( c_string_to_lisp_string
result = throw_exception( c_string_to_lisp_symbol( L"cond" ),
c_string_to_lisp_string
( L"Arguments to `cond` must be lists" ),
frame_pointer );
}
@ -1271,18 +1336,25 @@ lisp_cond( struct stack_frame *frame, struct cons_pointer frame_pointer,
* pointer to the frame in which the exception occurred.
*/
struct cons_pointer
throw_exception( struct cons_pointer message,
throw_exception( struct cons_pointer location,
struct cons_pointer message,
struct cons_pointer frame_pointer ) {
debug_print( L"\nERROR: ", DEBUG_EVAL );
debug_dump_object( message, DEBUG_EVAL );
struct cons_pointer result = NIL;
struct cons_space_object cell = pointer2cell( message );
struct cons_space_object *cell = &pointer2cell( message );
if ( cell.tag.value == EXCEPTIONTV ) {
if ( cell->tag.value == EXCEPTIONTV ) {
result = message;
} else {
result = make_exception( message, frame_pointer );
result =
make_exception( make_cons
( make_cons( privileged_keyword_location,
location ),
make_cons( make_cons
( privileged_keyword_payload,
message ), NIL ) ), frame_pointer );
}
return result;
@ -1295,7 +1367,7 @@ throw_exception( struct cons_pointer message,
* normally return. A function which detects a problem it cannot resolve
* *should* return an exception.
*
* * (exception message frame)
* * (exception message location)
*
* @param frame my stack frame.
* @param frame_pointer a pointer to my stack_frame.
@ -1310,7 +1382,9 @@ struct cons_pointer
lisp_exception( struct stack_frame *frame, struct cons_pointer frame_pointer,
struct cons_pointer env ) {
struct cons_pointer message = frame->arg[0];
return exceptionp( message ) ? message : throw_exception( message,
frame->arg[1],
frame->previous );
}
@ -1444,24 +1518,24 @@ struct cons_pointer lisp_source( struct stack_frame *frame,
struct cons_pointer frame_pointer,
struct cons_pointer env ) {
struct cons_pointer result = NIL;
struct cons_space_object cell = pointer2cell( frame->arg[0] );
struct cons_space_object *cell = &pointer2cell( frame->arg[0] );
struct cons_pointer source_key = c_string_to_lisp_keyword( L"source" );
switch ( cell.tag.value ) {
switch ( cell->tag.value ) {
case FUNCTIONTV:
result = c_assoc( source_key, cell.payload.function.meta );
result = c_assoc( source_key, cell->payload.function.meta );
break;
case SPECIALTV:
result = c_assoc( source_key, cell.payload.special.meta );
result = c_assoc( source_key, cell->payload.special.meta );
break;
case LAMBDATV:
result = make_cons( c_string_to_lisp_symbol( L"lambda" ),
make_cons( cell.payload.lambda.args,
cell.payload.lambda.body ) );
make_cons( cell->payload.lambda.args,
cell->payload.lambda.body ) );
break;
case NLAMBDATV:
result = make_cons( c_string_to_lisp_symbol( L"nlambda" ),
make_cons( cell.payload.lambda.args,
cell.payload.lambda.body ) );
make_cons( cell->payload.lambda.args,
cell->payload.lambda.body ) );
break;
}
// \todo suffers from premature GC, and I can't see why!
@ -1484,7 +1558,8 @@ struct cons_pointer c_append( struct cons_pointer l1, struct cons_pointer l2 ) {
c_append( c_cdr( l1 ), l2 ) );
}
} else {
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"append" ),
c_string_to_lisp_string
( L"Can't append: not same type" ), NIL );
}
break;
@ -1505,12 +1580,14 @@ struct cons_pointer c_append( struct cons_pointer l1, struct cons_pointer l2 ) {
pointer2cell( l1 ).tag.value );
}
} else {
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"append" ),
c_string_to_lisp_string
( L"Can't append: not same type" ), NIL );
}
break;
default:
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"append" ),
c_string_to_lisp_string
( L"Can't append: not a sequence" ), NIL );
break;
}
@ -1622,7 +1699,8 @@ struct cons_pointer lisp_let( struct stack_frame *frame,
bindings = make_cons( make_cons( symbol, val ), bindings );
} else {
result =
throw_exception( c_string_to_lisp_string
throw_exception( c_string_to_lisp_symbol( L"let" ),
c_string_to_lisp_string
( L"Let: cannot bind, not a symbol" ),
frame_pointer );
break;