PATCH: return status of let with floats

PATCH: return status of let with floats

[Peter Stephenson]

(( 0.3 ))

currently returns status 1 because there is an implicit cast to
integer.  As documented, it should simply test whether the result is
zero, i.e. should function identically to

(( 0.3 == 0 ))

where the implicit cast is of the 0 to 0.0.  Certainly this seems to me
more consistent and useful.  I don't have a ksh which handles floating
point to try out, unfortunately.

Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.92
diff -u -r1.92 builtin.c
--- Src/builtin.c	11 Dec 2002 16:03:21 -0000	1.92
+++ Src/builtin.c	18 Dec 2002 16:48:12 -0000
@@ -4759,13 +4759,14 @@
 int
 bin_let(char *name, char **argv, Options ops, int func)
 {
-    zlong val = 0;
+    mnumber val = zero_mnumber;
 
     while (*argv)
-	val = mathevali(*argv++);
+	val = matheval(*argv++);
     /* Errors in math evaluation in let are non-fatal. */
     errflag = 0;
-    return !val;
+    /* should test for fabs(val.u.d) < epsilon? */
+    return (val.type == MN_INTEGER) ? val.u.l == 0 : val.u.d == 0.0;
 }
 
 /* umask command.  umask may be specified as octal digits, or in the  *
Index: Src/exec.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/exec.c,v
retrieving revision 1.47
diff -u -r1.47 exec.c
--- Src/exec.c	4 Dec 2002 13:57:51 -0000	1.47
+++ Src/exec.c	18 Dec 2002 16:48:12 -0000
@@ -3087,7 +3087,7 @@
 execarith(Estate state, int do_exec)
 {
     char *e;
-    zlong val = 0;
+    mnumber val = zero_mnumber;
     int htok = 0;
 
     if (isset(XTRACE)) {
@@ -3101,7 +3101,7 @@
     if (isset(XTRACE))
 	fprintf(xtrerr, " %s", e);
 
-    val = mathevali(e);
+    val = matheval(e);
 
     cmdpop();
 
@@ -3110,7 +3110,8 @@
 	fflush(xtrerr);
     }
     errflag = 0;
-    return !val;
+    /* should test for fabs(val.u.d) < epsilon? */
+    return (val.type == MN_INTEGER) ? val.u.l == 0 : val.u.d == 0.0;
 }
 
 /* perform time ... command */

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: PATCH: return status of let with floats

[Oliver Kiddle]

On 18 Dec, Peter wrote:
 
> more consistent and useful.  I don't have a ksh which handles floating
> point to try out, unfortunately.

ksh93> (( 0.3 )) && echo yup
yup

So it looks like your change is consistent with it.

All of bash, pdksh and ksh 88/93 output 0 for `echo $(( ))' by the way
while zsh gives a bad math expression error so that should perhaps also
be changed.

Oliver

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Re: PATCH: return status of let with floats

[Peter Stephenson]

Oliver Kiddle wrote:
> All of bash, pdksh and ksh 88/93 output 0 for `echo $(( ))' by the way
> while zsh gives a bad math expression error so that should perhaps also
> be changed.

This handles that particular case, though I don't know if it's supposed
to be something more general.

Index: Src/math.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/math.c,v
retrieving revision 1.16
diff -u -r1.16 math.c
--- Src/math.c	30 Oct 2002 19:29:42 -0000	1.16
+++ Src/math.c	18 Dec 2002 17:58:44 -0000
@@ -961,7 +961,7 @@
     stack[0].val.u.l = 0;
     mathparse(prek);
     *ep = ptr;
-    DPUTS(!errflag && sp,
+    DPUTS(!errflag && sp > 0,
 	  "BUG: math: wallabies roaming too freely in outback");
 
     if (errflag) {
@@ -1084,6 +1084,9 @@
     if (errflag)
 	return;
     mtok = zzlex();
+    /* Handle empty input */
+    if (pc == TOPPREC && mtok == EOI)
+	return;
     checkunary(mtok, optr);
     while (prec[mtok] <= pc) {
 	if (errflag)

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


**********************************************************************
The information transmitted is intended only for the person or
entity to which it is addressed and may contain confidential 
and/or privileged material. 
Any review, retransmission, dissemination or other use of, or
taking of any action in reliance upon, this information by 
persons or entities other than the intended recipient is 
prohibited.  
If you received this in error, please contact the sender and 
delete the material from any computer.
**********************************************************************