Custom Query (1030 matches)

There is no reason for the hash table iterator to copy keys and values for lock-free hash tables. (The only reason it does now is that it's a bit hard to change the protocol so that it can stack-cons the key vector for some tables and not others).

with-readtable-iterator is a macro proposed as a de-facto standard extension to Common Lisp by Tobias Rittweiler. It is currently implemented in the with-readtable-iterator branch of Git repository git://repo.or.cz/sbcl/tcr.git (​gitweb).

The macro allows efficient iteration over the reader macros provided in a particular readtable, more than can be provided with ANSI-standard functionality, especially given very large values of char-code-limit. Tobias's named-readtable (​Darcs) for SBCL and Clozure CL, which implements Allegro-like named readtables, uses with-readtable-iterator to merge macros provided by multiple readtables into a single readtable.

Attached is a patch made against r10880 that implements this macro and exports it from CCL. The `with-readtable-iterator' macro body itself is borrowed from Tobias's SBCL implementation.

Hard to believe but this is what I'm getting:

? (= (+ .6 .8) 1.4)
NIL
? (+ .8 .6)
1.4000001
? (+ .6 .8)
1.4000001
? (+ .6 .8 .1)
1.5000001
? (- .8 .6)
0.19999999

I do not see this for other numbers, e.g.

? (+ .6 .9)
1.5
? (+ .6 .7)
1.3

.6 and .8 somehow have to be involved, but this is not systematic: e.g.

? (+ .1 .6 .8)
1.5

I tried other numbers but could not find similar behavior for addition, but for substraction i'm also getting:

? (- .9 .6)
0.29999995
? (- .6 .9)
-0.29999995
? (- .6 .5)
0.100000024
? (- .7 .8)
-0.100000024

I also seem to getting similar problems with multiplication but only with numbers 0<x<1 and with one decimal

this is one particular terminal test session:

$ ccl
Welcome to Clozure Common Lisp Version 1.2-r11241M  (DarwinX8664)!
? (= (+ .6 .8) 1.4)
NIL
? (= (+ .6 .9) 1.5)
T
? (+ .6 .8)
1.4000001
? (+ .6 .9)
1.5
? (+ .6 .7)
1.3
? (+ .8 .6)
1.4000001
? (+ .5 .6)
1.1
? (+ .8 .6 .1)
1.5000001
? (- .6 .8)
-0.19999999
? (- .5 .8)
-0.3
? (- .6 .6)
0.0
? (- .6 .7)
-0.099999964
? (* .1 .1)
0.010000001
? (* 1 1)
1
? (* 2 .1) 
0.2
? (* 1.1 1.1)
1.21
? (* 1.1 .1)
0.11000001
? (* .2 .2)
0.040000003
? (* .1 1)
0.1
? (* .1 .1111)
0.01111
? (* .1 .11)
0.011
? (* .1 .1)
0.010000001
? (* .11 .11)
0.0121

platform: Mac OS X 10.5.5 on 64bit intel
ccl: 1.2-r11241M (DarwinX8664) compile from svn checked out on Wed 29 Oct 2008

What could be the problem here?