73 lines
2.0 KiB
C++
73 lines
2.0 KiB
C++
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/* matherr
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Turbo-C Run Time Library
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Copyright (c) 1987 by Borland International. All rights reserved.
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*/
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#include <stdio.h>
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#include <math.h>
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#include <errno.h>
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/*
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When exceptions are detected in the maths library then a call is
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made to _matherr() with all the available information.
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That function does very little, except to map the exception "why"
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into either ERANGE or EDOMAIN in errno. Its main purpose is to
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act as a focal point for changes in error handling.
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For example, if you were writing a spreadsheet you might replace
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this function with one which pops up an error window explaining
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something like:
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"log (-2.0) caused domain error, in cell J7"
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and then longjmp() to a reset state in the spreadsheet and await
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the next command from the user.
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The important thing is that we don't know what error handling
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you want, but you are assured that all errors will arrive at
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matherr() with all the information you need to design a custom
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format.
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We do not ship as standard the function named matherr() which may
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be familiar to UNIX users, since the ANSI x3j11 draft specifies
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an incompatible style. This version is as close as we could
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get without breaking the ANSI rules. You can, however, convert
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this version to the UNIX style if you prefer. The necessary
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code is included but switched off.
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*/
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#ifdef UNIX_matherr
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char *whyS [] =
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{
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"argument domain error",
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"argument singularity ",
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"overflow range error ",
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"underflow range error",
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"total loss of significance",
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"partial loss of significance"
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};
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int matherr (struct exception *e)
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/*
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The default version of matherr() traditionally explains what has
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gone wrong and then kills the program.
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*/
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{
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fprintf (stderr,
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"%s (%8g,%8g): %s\n", e->name, e->arg1, e->arg2, whyS [e->type - 1]);
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exit (1);
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}
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#else
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int matherr (struct exception *e)
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{
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return (0);
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}
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#endif
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