[pure-lang-svn] SF.net SVN: pure-lang:[527] pure/trunk

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

Revision: 527
          http://pure-lang.svn.sourceforge.net/pure-lang/?rev=527&view=rev
Author:   agraef
Date:     2008-08-18 07:02:41 +0000 (Mon, 18 Aug 2008)

Log Message:
-----------
Add tail-recursive sequence operator.

Modified Paths:
--------------
    pure/trunk/ChangeLog
    pure/trunk/interpreter.cc
    pure/trunk/lib/prelude.pure
    pure/trunk/lib/primitives.pure
    pure/trunk/symtable.cc
    pure/trunk/symtable.hh

Modified: pure/trunk/ChangeLog
===================================================================
--- pure/trunk/ChangeLog	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/ChangeLog	2008-08-18 07:02:41 UTC (rev 527)
@@ -1,3 +1,11 @@
+2008-08-18  Albert Graef  <Dr....@t-...>
+
+	* interpreter.cc (codegen): Generate tail-recursive code for
+	sequence operator.
+
+	* lib/prelude.pure, lib/primitives.pure: Definition of $$ sequence
+	operator.
+
 2008-08-17  Albert Graef  <Dr....@t-...>
 
 	* pure.cc, interpreter.cc/h, runtime.cc: Overhaul of the script

Modified: pure/trunk/interpreter.cc
===================================================================
--- pure/trunk/interpreter.cc	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/interpreter.cc	2008-08-18 07:02:41 UTC (rev 527)
@@ -4233,7 +4233,12 @@
 	       (v = funcall(e, n, x)))
 	// recursive call to a global function
 	return v;
-      else if (n == 2 && f.tag() == symtab.catch_sym().f) {
+      else if (n == 2 && f.ftag() == symtab.seq_sym().f) {
+	// sequence operator
+	Value *u = codegen(x.xval1().xval2());
+	act_builder().CreateCall(module->getFunction("pure_freenew"), u);
+	return codegen(x.xval2());
+      } else if (n == 2 && f.tag() == symtab.catch_sym().f) {
 	// catch an exception; create a little anonymous closure to be called
 	// through pure_catch()
 	expr h = x.xval1().xval2(), y = x.xval2();

Modified: pure/trunk/lib/prelude.pure
===================================================================
--- pure/trunk/lib/prelude.pure	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/lib/prelude.pure	2008-08-18 07:02:41 UTC (rev 527)
@@ -45,6 +45,7 @@
 /* Operators. Note that the parser will automagically give unary minus the
    same precedence level as the corresponding binary operator. */
 
+infixl 0   $$ ;			// sequence operator
 infixr 0   $ ;			// right-associative application
 infixr 1   , ;			// pair (tuple)
 infix  2   => ;			// mapsto constructor

Modified: pure/trunk/lib/primitives.pure
===================================================================
--- pure/trunk/lib/primitives.pure	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/lib/primitives.pure	2008-08-18 07:02:41 UTC (rev 527)
@@ -201,12 +201,14 @@
 x::double==y::int	= x==y;
 x::double!=y::int	= x!=y;
 
-/* Logical connectives. Please note that these will be short-circuited only as
-   explicit calls! But we still want them to work if they are applied
-   partially, so we add these rules here. */
+/* Logical connectives and sequences. Please note that these enjoy
+   call-by-name and short-circuit evaluation only as explicit calls! But we
+   still want them to work if they are applied partially, so we add these
+   rules here. */
 
 x::int&&y::int		= x&&y;
 x::int||y::int		= x||y;
+x$$y			= y;
 
 /* Bigint arithmetic. */
 

Modified: pure/trunk/symtable.cc
===================================================================
--- pure/trunk/symtable.cc	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/symtable.cc	2008-08-18 07:02:41 UTC (rev 527)
@@ -120,6 +120,15 @@
     return sym(",", 1, infixr);
 }
 
+symbol& symtable::seq_sym()
+{
+  symbol *_sym = lookup("$$");
+  if (_sym)
+    return *_sym;
+  else
+    return sym("$$", 0, infixl);
+}
+
 symbol& symtable::not_sym()
 {
   symbol *_sym = lookup("not");

Modified: pure/trunk/symtable.hh
===================================================================
--- pure/trunk/symtable.hh	2008-08-17 22:56:36 UTC (rev 526)
+++ pure/trunk/symtable.hh	2008-08-18 07:02:41 UTC (rev 527)
@@ -49,6 +49,7 @@
   symbol& cons_sym();
   symbol& void_sym();
   symbol& pair_sym();
+  symbol& seq_sym();
   symbol& neg_sym() { return sym("neg"); }
   symbol& not_sym();
   symbol& bitnot_sym();


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