[pure-lang-svn] SF.net SVN: pure-lang: [400] pure/trunk

[<ag...@us...>]

Revision: 400
          http://pure-lang.svn.sourceforge.net/pure-lang/?rev=400&view=rev
Author:   agraef
Date:     2008-07-06 03:50:05 -0700 (Sun, 06 Jul 2008)

Log Message:
-----------
Move '=>' constructor from dict.pure to prelude.pure.

Modified Paths:
--------------
    pure/trunk/ChangeLog
    pure/trunk/examples/dict.pure
    pure/trunk/lib/prelude.pure
    pure/trunk/test/prelude.log

Modified: pure/trunk/ChangeLog
===================================================================
--- pure/trunk/ChangeLog	2008-07-06 10:06:08 UTC (rev 399)
+++ pure/trunk/ChangeLog	2008-07-06 10:50:05 UTC (rev 400)
@@ -1,5 +1,8 @@
 2008-07-06  Albert Graef  <Dr....@t-...>
 
+	* lib/prelude.pure: Added new "mapsto" constructor. Requested by
+	Jiri Spitz.
+
 	* runtime.cc (pure_sys_vars): Turn system constants into real
 	constant definitions.
 

Modified: pure/trunk/examples/dict.pure
===================================================================
--- pure/trunk/examples/dict.pure	2008-07-06 10:06:08 UTC (rev 399)
+++ pure/trunk/examples/dict.pure	2008-07-06 10:50:05 UTC (rev 400)
@@ -33,10 +33,6 @@
 /* Empty tree constant, consider this private. */
 nullary nil;
 
-/* Definition of the mapsto operator used for key=>value pairs */
-infix 2 => ;
-
-
 /*****
 Tree for dict and hdict is either:
 -  nil  (empty tree) or

Modified: pure/trunk/lib/prelude.pure
===================================================================
--- pure/trunk/lib/prelude.pure	2008-07-06 10:06:08 UTC (rev 399)
+++ pure/trunk/lib/prelude.pure	2008-07-06 10:50:05 UTC (rev 400)
@@ -47,6 +47,7 @@
 
 infixr 0   $ ;			// right-associative application
 infixr 1   , ;			// pair (tuple)
+infix  2   => ;			// mapsto constructor
 infixr 2   || ;			// logical or (short-circuit)
 infixr 3   && ;			// logical and (short-circuit)
 prefix 3   not ;		// logical negation
@@ -89,6 +90,13 @@
 uncurry3 f (x,y,z)
 		= f x y z;
 
+/* "Mapsto" operator. This constructor is declared here so that it can be used
+   in other standard library modules to denote special kind of pairs which map
+   keys to values. Here we only define equality of such pairs. */
+
+(x=>v)==(y=>w)	= if x==y then v==w else 0;
+(x=>v)!=(y=>w)	= if x!=y then 1 else v!=w;
+
 /* Poor man's tuples(TM). These are constructed with the pairing operator ',',
    are always flat and associate to the right. The empty tuple, denoted (), is
    neutral with respect to ','. Operations are provided to test for equality/

Modified: pure/trunk/test/prelude.log
===================================================================
--- pure/trunk/test/prelude.log	2008-07-06 10:06:08 UTC (rev 399)
+++ pure/trunk/test/prelude.log	2008-07-06 10:50:05 UTC (rev 400)
@@ -10,6 +10,8 @@
 curry3 f/*0:0001*/ x/*0:001*/ y/*0:01*/ z/*0:1*/ = f/*0:0001*/ (x/*0:001*/,y/*0:01*/,z/*0:1*/);
 uncurry f/*0:01*/ (x/*0:101*/,y/*0:11*/) = f/*0:01*/ x/*0:101*/ y/*0:11*/;
 uncurry3 f/*0:01*/ (x/*0:101*/,y/*0:1101*/,z/*0:111*/) = f/*0:01*/ x/*0:101*/ y/*0:1101*/ z/*0:111*/;
+(x/*0:0101*/=>v/*0:011*/)==(y/*0:101*/=>w/*0:11*/) = if x/*0:0101*/==y/*0:101*/ then v/*0:011*/==w/*0:11*/ else 0;
+(x/*0:0101*/=>v/*0:011*/)!=(y/*0:101*/=>w/*0:11*/) = if x/*0:0101*/!=y/*0:101*/ then 1 else v/*0:011*/!=w/*0:11*/;
 x/*0:01*/,() = x/*0:01*/;
 (),y/*0:1*/ = y/*0:1*/;
 (x/*0:0101*/,y/*0:011*/),z/*0:1*/ = x/*0:0101*/,y/*0:011*/,z/*0:1*/;


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