[svn:parrot] r41578 - in branches/pct-rx: compilers/pct/src/PAST examples/regex

[pmichaud at svn.parrot.org]

Author: pmichaud
Date: Wed Sep 30 14:45:23 2009
New Revision: 41578
URL: https://trac.parrot.org/parrot/changeset/41578

Log:
[pct-rx]:  Add 'alt_longest' node type, peeks for it.

Modified:
   branches/pct-rx/compilers/pct/src/PAST/Compiler-Regex.pir
   branches/pct-rx/compilers/pct/src/PAST/Regex.pir
   branches/pct-rx/examples/regex/05-alt-past.nqp

Modified: branches/pct-rx/compilers/pct/src/PAST/Compiler-Regex.pir
==============================================================================
--- branches/pct-rx/compilers/pct/src/PAST/Compiler-Regex.pir	Wed Sep 30 14:19:01 2009	(r41577)
+++ branches/pct-rx/compilers/pct/src/PAST/Compiler-Regex.pir	Wed Sep 30 14:45:23 2009	(r41578)
@@ -234,6 +234,19 @@
 .end
 
 
+=item alt_longest(PAST::Regex node)
+
+Same as 'alt' above, but use declarative/LTM semantics.
+(Currently we cheat and just use 'alt' above.)
+
+=cut
+
+.sub 'alt_longest' :method
+    .param pmc node
+    .tailcall self.'alt'(node)
+.end
+
+
 =item concat(PAST::Regex node)
 
 Handle a concatenation of regexes.

Modified: branches/pct-rx/compilers/pct/src/PAST/Regex.pir
==============================================================================
--- branches/pct-rx/compilers/pct/src/PAST/Regex.pir	Wed Sep 30 14:19:01 2009	(r41577)
+++ branches/pct-rx/compilers/pct/src/PAST/Regex.pir	Wed Sep 30 14:45:23 2009	(r41578)
@@ -49,18 +49,22 @@
 =cut
 
 .sub 'peek' :method
+    .local pmc list
+    list = new ['ResizablePMCArray']
+
     $I0 = isa self, ['PAST';'Regex']
     unless $I0 goto peek_stop
 
-    .local pmc child_it, list
+    .local pmc child_it
     child_it = self.'iterator'()
-    list = new ['ResizablePMCArray']
 
     .local string pasttype
     pasttype = self.'pasttype'()
-    if pasttype == 'literal' goto literal
     if pasttype == 'concat' goto concat
     if pasttype == '' goto concat
+    if pasttype == 'literal' goto literal
+    if pasttype == 'alt' goto alt
+    if pasttype == 'alt_longest' goto alt_longest
 
   peek_stop:
     list = 0
@@ -71,6 +75,23 @@
     list[0] = ''
     .return (list)
 
+  # temporal alternation returns the prefixes of its first child
+  alt:
+    unless child_it goto peek_stop
+    $P0 = shift child_it
+    .tailcall 'peek'($P0)
+
+  # declarative alternation returns prefixes of all children
+  alt_longest:
+    unless child_it goto alt_longest_done
+    $P0 = shift child_it
+    $P1 = 'peek'($P0)
+    $I0 = elements list
+    splice list, $P1, $I0, 0
+    goto alt_longest
+  alt_longest_done:
+    .return (list)
+
   concat:
     unless child_it goto peek_zero
     $P0 = shift child_it

Modified: branches/pct-rx/examples/regex/05-alt-past.nqp
==============================================================================
--- branches/pct-rx/examples/regex/05-alt-past.nqp	Wed Sep 30 14:19:01 2009	(r41577)
+++ branches/pct-rx/examples/regex/05-alt-past.nqp	Wed Sep 30 14:45:23 2009	(r41578)
@@ -1,7 +1,7 @@
 # nqp
 
 
-say("# regex { 'foo' | 'bar' | 'baz' }");
+say("# regex { 'foo' || 'bar' || 'baz' }");
 my $past :=
   PAST::Regex.new(
     PAST::Regex.new(
@@ -14,4 +14,21 @@
   );
 
 say(PAST::Compiler.compile($past, :target('pir')));
+for $past.peek { say($_); }
+
+say("# regex { ['foo' | 'bar' | 'baz'] 'xyz' }");
+my $past :=
+  PAST::Regex.new(
+    PAST::Regex.new(
+      PAST::Regex.new('foo', :pasttype('literal')),
+      PAST::Regex.new('bar', :pasttype('literal')),
+      PAST::Regex.new('baz', :pasttype('literal')),
+      :pasttype('alt_longest')
+    ),
+    PAST::Regex.new('xyz', :pasttype('literal')),
+    PAST::Regex.new(:pasttype('pass')),
+  );
+
+say(PAST::Compiler.compile($past, :target('pir')));
+for $past.peek { say($_); }