Accept multiple columns on .classify. Related to #501

Changes

@@ -2,6 +2,7 @@ Revision history for Red
 
 {{$NEXT}}
     - Fix test on Pg
+    - Accept .classify with multiple columns
 
 0.1.66  2022-12-18T21:55:33Z
     - Add `is view`

lib/Red/ResultAssociative.pm6

@@ -11,6 +11,7 @@ unit role Red::ResultAssociative[$of, Red::AST $key-of] does Associative;
 
 has Red::AST    $!key-of = $key-of;
 has             $.rs is required;
+has             @.next-level;
 
 #| type of the value
 method of     { $of }
@@ -37,7 +38,12 @@ method elems {
 
 #| return a ResultSeq for the given key
 method AT-KEY($key) {
-    $!rs.grep: { Red::AST::Eq.new: $!key-of, ast-value($key), :bind-right }
+    my \resultseq = $!rs.grep: { Red::AST::Eq.new: $!key-of, ast-value($key), :bind-right }
+    do if @!next-level {
+        Red::ResultAssociative[$of, @!next-level.head].new: :rs(resultseq), |(:next-level(@!next-level.skip) if @!next-level.elems > 1)
+    } else {
+        resultseq
+    }
 }
 
 method iterator {

lib/Red/ResultSeq.pm6

@@ -288,7 +288,7 @@ method classify(\SELF: &func, :&as = { $_ } --> Red::ResultAssociative) is hidde
     } else {
         my \key   = func SELF.of;
         my \value = as   SELF.of;
-        Red::ResultAssociative[value, key].new: :rs(SELF)
+        Red::ResultAssociative[value, key.head].new: :rs(SELF), |(:next-level(key.skip) if key.elems > 1)
     }
 }
 

t/27-classify.t

@@ -42,4 +42,14 @@ is-deeply Bla.^all.classify(*.bla).Set, set(<test1 test2>);
 is-deeply Bla.^all.map(*.bla).Bag, bag(<test1 test1 test2>);
 is-deeply Bla.^all.map(*.bla).Set, set(<test1 test2>);
 
+my %d := Bla.^all.classify({ .bla, .id });
+is %d.elems, 2;
+isa-ok %d<test1>, Red::ResultAssociative;
+is %d<test1>.elems, 2;
+is %d<test1>.keys, <1 2>;
+
+isa-ok %d<test2>, Red::ResultAssociative;
+is %d<test2>.elems, 1;
+is %d<test2>.keys, <3>;
+
 done-testing;