The GLR of DBDIsh. $sth.allrows now returns Seq

Fetching rows is now lazy, plus:
- named ':hash' of .row method is now implemented by the role.
- legacy '.fetchrow' requirement removed from drivers, a simple one
  implement by the role.
- Allows driver's ._row method return a simple list of typed values

lib/DBDish/StatementHandle.pm6

@@ -3,38 +3,42 @@ use v6;
 =begin pod
 =head2 role DBDish::StatementHandle
 The Connection C<prepare> method returns a StatementHandle object that
-mainly provides the C<execute> and C<finish> methods. It also has all the methods from C<DBDish::Role::ErrorHandling>.
+should provides the C<execute> and C<finish> methods.
+
+A Statetement handle should provide also the low-level C<_row> and C<_free>
+methods.
+
+It also has all the methods from C<DBDish::Role::ErrorHandling>.
 =end pod
 
 need DBDish::ErrorHandling;
 
 unit role DBDish::StatementHandle does DBDish::ErrorHandling;
 
+my role IntTrue { method Bool { self.defined } };
 
 has Int $.Executed = 0;
 has Bool $.Finished = True;
 has Int $!affected_rows;
 has @!column-name;
 has @!column-type;
 
-method dispose() {
-    self.finish unless $!Finished;
-    self._free;
-    my \id := self.WHICH.Str;
-    ?($.parent.Statements{id}:delete);
-}
-#Avoid leaks if explicit dispose isn't used by the user.
-submethod DESTROY() {
-    self.dispose;
-}
+# My defined interface
+method execute(*@ --> IntTrue) { ... }
+method finish(--> Bool) { ... }
+method _row(--> Array) { ... }
+method _free() { ... }
+
 method !ftr() {
     $.parent.last-sth-id = self.WHICH;
 }
+
 method !enter-execute() {
     self.finish unless $!Finished;
     $!affected_rows = Nil;
     self!ftr;
 }
+
 method !done-execute(Int $rows, Bool $was-select) {
     $!Executed++;
     $!Finished = False;
@@ -48,20 +52,28 @@ method new(*%args) {
     %args<parent>.Statements{sth.WHICH} = sth;
 }
 
-my role IntTrue { method Bool { self.defined } };
+method dispose() {
+    self.finish unless $!Finished;
+    self._free;
+    my \id := self.WHICH.Str;
+    ?($.parent.Statements{id}:delete);
+}
+#Avoid leaks if explicit dispose isn't used by the user.
+submethod DESTROY() {
+    self.dispose;
+}
+
 method rows {
     $!affected_rows but IntTrue;
 }
 
-method _free() { ... }
-method finish(--> Bool) { ... }
-method fetchrow() { ... }
-method execute(*@ --> IntTrue) { ... }
-method	_row(:$hash) { ... }
-
 method row(:$hash) {
     self!ftr;
-    self._row(:$hash);
+    if my \r = self._row {
+	$hash ?? (@!column-name Z=> @(r)).hash !! r.Array;
+    } else {
+	$hash ?? % !! @;
+    }
 }
 
 method column-names {
@@ -73,37 +85,50 @@ method column-types {
 }
 
 multi method allrows(:$array-of-hash!) {
-    my @rows;
-    while self.row(:hash) -> %row {
-	@rows.push(%row);
+    gather {
+	while self.row(:hash) -> %r {
+	    take %r;
+	}
     }
-    @rows;
 }
 
 multi method allrows(:$hash-of-array!) {
-    my @names := @!column-name;
-    my %rows = @names Z=> [] xx *;
+    my %rows = @!column-name Z=> [] xx *;
     while self.row -> @a {
-	for @a Z @names -> ($v, $n) {
+	for @a Z @!column-name -> ($v, $n) {
 	    %rows{$n}.push: $v;
 	}
     }
     %rows;
 }
 
 multi method allrows() {
-    my @rows;
-    while self.row -> @r {
-         @rows.push(@r);
+    gather {
+	while self.row -> @r {
+	    take @r;
+	}
     }
-    @rows;
 }
 
-method fetchrow-hash() {
+# Legacy
+method fetchrow {
+    if my \r = self._row {
+	my @ = (r.map: { .defined ?? ~$_ !! Str });
+    } else { @ };
+}
+
+method fetchrow-hash {
     hash @!column-name Z=> self.fetchrow;
 }
+method fetchrow_hashref { self.fetchrow-hash }
 
-method fetchrow_hashref { $.fetchrow-hash }
+method fetchall_hashref(Str $key) {
+    my %results;
+    while self.fetch-hash -> \h {
+	%results{h{$key}} = h;
+    }
+    %results;
+}
 
 method fetchall-hash {
     my @names := @!column-name;
@@ -113,7 +138,7 @@ method fetchall-hash {
             %res{$n}.push: $v;
         }
     }
-    return %res;
+    %res;
 }
 
 method fetchall-AoH {
@@ -133,13 +158,7 @@ method fetchall-array {
 }
 
 method fetchrow_array { self.fetchrow }
-
-method fetchrow_arrayref {
-    $.fetchrow;
-}
-
-method fetch() {
-    $.fetchrow;
-}
+method fetchrow_arrayref { self.fetchrow; }
+method fetch { self.fetchrow; }
 
 method fetchall_arrayref  { [ self.fetchall-array.eager ] }