OBJ
readNumber(OBJ inStream, char firstChar, int isNegative){
//printf(YEL "\nreadNumber>" RESET);
/*
* TO-DO refactor!
*/
jscheme_int64 *iVal = NULL;
char ch;
OBJ retVal;
// substract the ASCII value of '0' from char to get the actual value between 0 and 9.
jscheme_int64 start = (jscheme_int64) firstChar - '0';
if(isNegative) start *= -1;
iVal = &start;
while( isDigit( ch = nextChar(inStream) )){
//iVal = iVal * 10 + ( (int)ch - '0');
jscheme_int64 ch_val = (jscheme_int64) ch - '0';
if(isNegative){
int mul = __builtin_smull_overflow(*iVal, 10, iVal);
int sub = __builtin_ssubl_overflow(*iVal, ch_val, iVal);
if( mul || sub ){
if(thisIsTheEnd(inStream)){
prompt_on();
}
js_error("readNumber: integer underflow", newInteger(*iVal));
}
}else{
int mul = __builtin_smull_overflow(*iVal, 10, iVal);
int add = __builtin_saddl_overflow(*iVal, ch_val, iVal);
if( mul || add ){
if(thisIsTheEnd(inStream)){
prompt_on();
}
js_error("readNumber: integer overflow", newInteger(*iVal));
}
}
}
unreadChar(inStream, ch);
retVal = newInteger( *iVal );
return retVal;
}
OBJ
builtin_minus(int numArgs){
OBJ theArg;
switch (numArgs){
case 0:
js_error("(-): at least one arg expected", js_nil);
/* NOT REACHED */
case 1:
theArg = POP();
if( !ISINTEGER(theArg)){
js_error("(-): non-integer argument", theArg);
}
return newInteger( -INTVAL(theArg) );
default:
theArg = NTH_ARG(numArgs, 0);
if( !ISINTEGER(theArg)){
POPN(numArgs);
js_error("(-): non-integer argument", theArg);
}
jscheme_int64 *difference = NULL;
jscheme_int64 start = INTVAL(theArg);
difference = &start;
for(int i = 1; i < numArgs; i++){
OBJ nextArg = NTH_ARG(numArgs, i);
if( !ISINTEGER(nextArg)){
POPN(numArgs);
js_error("(-): non-integer argument", theArg);
}
if(__builtin_ssubl_overflow(*difference, INTVAL(nextArg), difference)){
// clean stack
POPN(numArgs);
js_error("(-): integer overflow", newInteger(*difference));
};
}
POPN(numArgs);
return newInteger(*difference);
}
/* NOT REACHED */
return js_nil;
}
extern "C" Box* sub_i64_i64(i64 lhs, i64 rhs) {
i64 result;
if (!__builtin_ssubl_overflow(lhs, rhs, &result))
return boxInt(result);
return longSub(boxLong(lhs), boxLong(rhs));
}
