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* 1+ and 1- in C
@ 2005-04-10 22:17 Kevin Ryde
  2005-04-10 22:29 ` Bruce Korb
  2005-05-24 17:03 ` Marius Vollmer
  0 siblings, 2 replies; 4+ messages in thread
From: Kevin Ryde @ 2005-04-10 22:17 UTC (permalink / raw)


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I propose to do 1+ and 1- in C so they're as fast as plain + and -.
Calling scm_sum and scm_difference will still get goops/generics
dispatch the same as the scheme code, if I'm not mistaken.


[-- Attachment #2: numbers.c.oneplus.diff --]
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--- numbers.c.~1.277.~	2005-03-13 11:17:05.000000000 +1100
+++ numbers.c	2005-04-10 09:31:40.000000000 +1000
@@ -4107,6 +4107,16 @@
 }
 
 
+SCM_DEFINE (scm_oneplus, "1+", 1, 0, 0, 
+            (SCM x),
+	    "Return @math{@var{x}+1}.")
+#define FUNC_NAME s_scm_oneplus
+{
+  return scm_sum (x, SCM_I_MAKINUM (1));
+}
+#undef FUNC_NAME
+
+
 SCM_GPROC1 (s_difference, "-", scm_tc7_asubr, scm_difference, g_difference);
 /* If called with one argument @var{z1}, -@var{z1} returned. Otherwise
  * the sum of all but the first argument are subtracted from the first
@@ -4342,6 +4352,16 @@
 #undef FUNC_NAME
 
 
+SCM_DEFINE (scm_oneminus, "1-", 1, 0, 0, 
+            (SCM x),
+	    "Return @math{@var{x}-1}.")
+#define FUNC_NAME s_scm_oneminus
+{
+  return scm_difference (x, SCM_I_MAKINUM (1));
+}
+#undef FUNC_NAME
+
+
 SCM_GPROC1 (s_product, "*", scm_tc7_asubr, scm_product, g_product);
 /* "Return the product of all arguments.  If called without arguments,\n"
  * "1 is returned."

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: 1+ and 1- in C
  2005-04-10 22:17 1+ and 1- in C Kevin Ryde
@ 2005-04-10 22:29 ` Bruce Korb
  2005-04-10 23:30   ` Kevin Ryde
  2005-05-24 17:03 ` Marius Vollmer
  1 sibling, 1 reply; 4+ messages in thread
From: Bruce Korb @ 2005-04-10 22:29 UTC (permalink / raw)


On Sunday 10 April 2005 03:17 pm, Kevin Ryde wrote:
> I propose to do 1+ and 1- in C so they're as fast as plain + and -.
> Calling scm_sum and scm_difference will still get goops/generics
> dispatch the same as the scheme code, if I'm not mistaken.

Shouldn't the name for the subtraction code be ``less one'' or
the alias be ``-1+'' or some such?  You are decrementing, yes?


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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: 1+ and 1- in C
  2005-04-10 22:29 ` Bruce Korb
@ 2005-04-10 23:30   ` Kevin Ryde
  0 siblings, 0 replies; 4+ messages in thread
From: Kevin Ryde @ 2005-04-10 23:30 UTC (permalink / raw)
  Cc: guile-devel

Bruce Korb <bruce.korb@gmail.com> writes:
>
> Shouldn't the name for the subtraction code be ``less one''

The C name?  That can be anything.

> or the alias be ``-1+''

I guess that was r2rs, or something.  It's gone in 1.8.

I'm only looking at moving a bit of what's already in boot-9.
Personally I quite like 1-.

> You are decrementing, yes?

Yep.


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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: 1+ and 1- in C
  2005-04-10 22:17 1+ and 1- in C Kevin Ryde
  2005-04-10 22:29 ` Bruce Korb
@ 2005-05-24 17:03 ` Marius Vollmer
  1 sibling, 0 replies; 4+ messages in thread
From: Marius Vollmer @ 2005-05-24 17:03 UTC (permalink / raw)


Kevin Ryde <user42@zip.com.au> writes:

> I propose to do 1+ and 1- in C so they're as fast as plain + and -.

Yes, why not.  Maybe it would even be worth it to special case
fixnums.

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^ permalink raw reply	[flat|nested] 4+ messages in thread

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2005-04-10 22:17 1+ and 1- in C Kevin Ryde
2005-04-10 22:29 ` Bruce Korb
2005-04-10 23:30   ` Kevin Ryde
2005-05-24 17:03 ` Marius Vollmer

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