[dotnet] implement regex subrule compilation

[P6Objects] implement named subrule "before" add a test.
jnthn · Dec 6, 2010 · 55673ae · 55673ae
1 parent ce8a2fe
commit 55673ae
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Showing 3 changed files with 33 additions and 3 deletions.
diff --git a/common/NQP/P6Objects.pm b/common/NQP/P6Objects.pm
@@ -130,6 +130,12 @@ class Regex::Cursor {
         self.CREATE();
     }
 
+    method Bool() {
+        nqp::repr_defined($!match)
+            ?? ?$!match
+            !! 0
+    }
+
     method CREATE() {
         nqp::instance_of(self)
     }
@@ -491,6 +497,16 @@ class Regex::Cursor {
         $!debug := nqp::repr_defined($arg) ?? $arg !! $TRUE;
         1
     }
+
+    method before($regex?) {
+        my @ret := self.cursor_start;
+        my $cur := @ret[0];
+        my $pos := @ret[1];
+
+        $cur.cursor_pass($pos, 'before')
+            if nqp::repr_defined($regex) && $regex($cur);
+        $cur;
+    }
 }
 
 class Regex::Regex {

diff --git a/dotnet/compiler/PAST2DNSTCompiler.pm b/dotnet/compiler/PAST2DNSTCompiler.pm
@@ -1625,7 +1625,6 @@ our multi sub dnst_regex(PAST::Regex $r) {
         #my $subdnst := $posargs.shift;
 
         my $negate := $r.negate;
-        my $testop := $negate ?? 'if' !! 'unless';
 
         my $subtype := $r.subtype;
         my $backtrack := $r.backtrack;
@@ -1634,12 +1633,25 @@ our multi sub dnst_regex(PAST::Regex $r) {
 
         $stmts.push($cdnst);
 
+        my $call := dnst_for(PAST::Op.new(
+            :pasttype('callmethod'), :name('Bool'),
+            cursorop($name, $posargs)
+        ));
+
+        # the logic here *appears* inverted because of the if_then.
+        $call := dnst_for(PAST::Op.new(
+            :pasttype('call'), :name('&prefix:<!>'),
+            $call
+        )) unless $negate;
+
         $stmts.push(if_then(:bool(0),
-            unbox('int', cursorop($name, $posargs)),
+            unbox('int', $call),
             $*re_fail
         ));
 
-        if $subtype ne 'zerowidth' {
+        if $subtype eq 'zerowidth' {
+
+        } else {
 
         }
     }

diff --git a/t/nqp/45-smartmatch.t b/t/nqp/45-smartmatch.t
@@ -28,3 +28,5 @@ ok(("abcd" ~~ /[[a|ab]|abc]d/) eq 'abcd', 'deep backtracking works');
 ok(("bbbbac" ~~ /[b+ b a $] | bbbbac/) eq 'bbbbac', 'greedy quantifier works');
 
 ok(("bbbbac" ~~ /[b+? b ac]/) eq 'bbbbac', 'frugal quantifier works');
+
+ok(("ab" ~~ /<?before ab> a/) eq 'a', 'subrule "before" works');