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(read1): Handle infinities, NaN and -0.0 specially.

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(isfloat_string): Accept e+INF and e+NAN as exponents.
This commit is contained in:
Richard M. Stallman 1998-02-02 01:08:52 +00:00
parent 6a7df83b34
commit eb659c4114
1 changed files with 28 additions and 1 deletions
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29
src/lread.c
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@ -1907,7 +1907,23 @@ read1 (readcharfun, pch, first_in_list)
}
#ifdef LISP_FLOAT_TYPE
if (isfloat_string (read_buffer))
return make_float (atof (read_buffer));
{
double value = atof (read_buffer);
if (read_buffer[0] == '-' && value == 0.0)
value *= -1.0;
/* The only way this can be true, after isfloat_string
returns 1, is if the input ends in e+INF or e+NaN. */
if (p[-1] == 'F' || p[-1] == 'N')
{
if (p[-1] == 'N')
value = 0.0 / 0.0;
else if (read_buffer[0] == '-')
value = -1.0e999;
else
value = 1.0e999;
}
return make_float (value);
}
#endif
}
@ -1968,6 +1984,17 @@ isfloat_string (cp)
while (*cp >= '0' && *cp <= '9')
cp++;
}
else if (cp[-1] == '+' && cp[0] == 'I' && cp[1] == 'N' && cp[2] == 'F')
{
state |= EXP_INT;
cp += 3;
}
else if (cp[-1] == '+' && cp[0] == 'N' && cp[1] == 'a' && cp[2] == 'N')
{
state |= EXP_INT;
cp += 3;
}
return (((*cp == 0) || (*cp == ' ') || (*cp == '\t') || (*cp == '\n') || (*cp == '\r') || (*cp == '\f'))
&& (state == (LEAD_INT|DOT_CHAR|TRAIL_INT)
|| state == (DOT_CHAR|TRAIL_INT)