simon/post-scarcity
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity

OK, it is BETTER, but not FIXED.

Browse source 
(expt 2 63) goes weirdly wrong - returns T.

Internal representation is correct, so fault is in print.
This commit is contained in:
Simon Brooke 2019-02-15 18:48:30 +00:00
parent 71354d0f86
commit baf8d6669d
1 changed files with 31 additions and 39 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

70
src/arith/integer.c
View file

@ -240,7 +240,10 @@ struct cons_pointer append_digit( struct cons_pointer partial, struct cons_point
/**
* Return a pointer to an integer representing the product of the integers
* pointed to by `a` and `b`. If either isn't an integer, will return nil.
* \todo it is MUCH more complicated than this!
*
* Yes, this is one of Muhammad ibn Musa al-Khwarizmi's original recipes, so
* you'd think it would be easy; the reason that each step is documented is
* because I did not find it so.
*
* @param a an integer;
* @param b an integer.
@ -339,38 +342,28 @@ struct cons_pointer integer_to_string_add_digit( int digit, int digits,
* when we get to the last digit from one integer cell, we have potentially
* to be looking to the next. H'mmmm.
*/
/*
* \todo this blows up when printing three-cell integers, but works fine
* for two-cell. What's happening is that when we cross the barrier we
* SHOULD print 2^120, but what we actually print is 2^117. H'mmm.
*/
struct cons_pointer integer_to_string( struct cons_pointer int_pointer,
int base ) {
int base ) {
struct cons_pointer result = NIL;
struct cons_space_object integer = pointer2cell( int_pointer );
__int128_t accumulator = llabs( integer.payload.integer.value );
bool is_negative = integer.payload.integer.value < 0;
int digits = 0;
if ( accumulator == 0 && nilp( integer.payload.integer.more ) ) {
result = c_string_to_lisp_string( L"0" );
} else {
while ( accumulator > 0 || !nilp( integer.payload.integer.more ) ) {
if ( !nilp( integer.payload.integer.more ) ) {
integer = pointer2cell( integer.payload.integer.more );
accumulator += integer.payload.integer.value;
debug_print
( L"integer_to_string: crossing cell boundary, accumulator is: ",
DEBUG_IO );
debug_print_128bit( accumulator, DEBUG_IO );
debug_println( DEBUG_IO );
}
if ( integerp( int_pointer ) ) {
struct cons_pointer next = pointer2cell( int_pointer ).payload.integer.more;
__int128_t accumulator = llabs( pointer2cell( int_pointer ).payload.integer.value );
bool is_negative = pointer2cell( int_pointer ).payload.integer.value < 0;
int digits = 0;
do {
if ( accumulator == 0 && nilp( next ) ) {
result = c_string_to_lisp_string( L"0" );
} else {
while ( accumulator > 0 || !nilp( next ) ) {
if ( accumulator < MAX_INTEGER && !nilp( next ) ) {
accumulator += (pointer2cell(next).payload.integer.value << 60);
next = pointer2cell(next).payload.integer.more;
}
int offset = ( int ) ( accumulator % base );
debug_printf( DEBUG_IO,
L"integer_to_string: digit is %ld, hexadecimal is %c, accumulator is: ",
offset, hex_digits[offset] );
L"integer_to_string: digit is %ld, hexadecimal is %c, accumulator is: ",
offset, hex_digits[offset] );
debug_print_128bit( accumulator, DEBUG_IO );
debug_print( L"; result is: ", DEBUG_IO );
debug_print_object( result, DEBUG_IO );
@ -379,20 +372,19 @@ struct cons_pointer integer_to_string( struct cons_pointer int_pointer,
result =
integer_to_string_add_digit( offset, ++digits, result );
accumulator = accumulator / base;
} while ( accumulator > base );
}
}
if ( stringp( result )
&& pointer2cell( result ).payload.string.character == L',' ) {
/* if the number of digits in the string is divisible by 3, there will be
* an unwanted comma on the front. */
struct cons_pointer tmp = result;
result = pointer2cell( result ).payload.string.cdr;
//dec_ref( tmp );
}
if ( stringp( result )
&& pointer2cell( result ).payload.string.character == L',' ) {
/* if the number of digits in the string is divisible by 3, there will be
* an unwanted comma on the front. */
result = pointer2cell( result ).payload.string.cdr;
}
if ( is_negative ) {
result = make_string( L'-', result );
if ( is_negative ) {
result = make_string( L'-', result );
}
}
}