Fix the INTERACT disambiguation mode

The code that processes the INDEX didn't match the format of the index
anymore, and probably was broken since the great list refactor a few
years ago. It was also much more complicated than necessary, since the
current index contains only simple Type::X entries.

So for now, make a very simple implementation that displays a list of
choices and lets the user pick one by number (or unique substring).

If any additional features are added to INDEX in the future, then this
can be replaced.

bin/p6doc

@@ -256,83 +256,61 @@ multi sub MAIN('lookup', $key) {
 }
 
 sub disambiguate-f-search($docee, %data) {
-    my %found;
 
-    for <routine method sub> -> $pref {
-        my $ndocee = $pref ~ " " ~ $docee;
-
-        if %data{$ndocee} {
-            my @types = %data{$ndocee}.values>>.Str.grep({ $^v ~~ /^ 'Type' / });
-            @types = [gather @types.deepmap(*.take)].unique.list;
-            @types.=grep({!/^ $pref \h/});
-            %found{$ndocee}.push: @types X~ $docee;
-        }
-    }
+    my @keys = (<method routine sub> X $docee)».join(' ');
+    my @found = %data{@keys}.grep(*.defined).map(
+            # Each entry is a list of 2-element lists; we want just the
+            # first, and then slip the results into a single flat list
+            |*.map(*.first)
+        ).unique X~ $docee;
 
     my $final-docee;
-    my $total-found = %found.values.map( *.elems ).sum;
-    if ! $total-found {
+    if ! @found {
         say "No documentation found for a routine named '$docee'";
         exit 2;
-    } elsif $total-found == 1 {
-        $final-docee = %found.values[0];
+    } elsif @found == 1 {
+        $final-docee = @found.head;
     } else {
         say "We have multiple matches for '$docee'\n";
 
-        my %options;
-        for %found.keys -> $key {
-            %options{$key}.push: %found{$key};
-        }
-        my @opts = %options.values.map({ @($^a) });
-
-        # 's' => Type::Supply.grep, ... | and we specifically want the %found values,
-        #                               | not the presentation-versions in %options
         if INTERACT {
-            my $total-elems = %found.values.map( +* ).sum;
-            if +%found.keys < $total-elems {
-                my @prefixes = (1..$total-elems) X~ ") ";
-                say "\t" ~ ( @prefixes Z~ @opts ).join("\n\t") ~ "\n";
-            } else {
-                say "\t" ~ @opts.join("\n\t") ~ "\n";
-            }
-            $final-docee = prompt-with-options(%options, %found);
+            $final-docee = prompt-with-options(@found);
         } else {
-            say "\t" ~ @opts.join("\n\t") ~ "\n";
+            say "\t", $_ for @found;
             exit 1;
         }
     }
 
     return $final-docee;
 }
 
-sub prompt-with-options(%options, %found) {
+sub prompt-with-options(@found) {
     my $final-docee;
 
-    my %prefixes = do for %options.kv -> $k,@o { @o.map(*.comb[0].lc) X=> %found{$k} };
+    printf "%3d)  %s\n", .key + 1, .value for @found.pairs;
 
-    if %prefixes.values.grep( -> @o { +@o > 1 } ) {
-        my (%indexes,$base-idx);
-        $base-idx = 0;
-        for %options.kv -> $k,@o {
-            %indexes.push: @o>>.map({ ++$base-idx }) Z=> @(%found{$k});
-        }
-        %prefixes = %indexes;
-    }
+    my $prompt-text = "\nNarrow your choice (1 .. @found.elems()): ";
 
-    my $prompt-text = "Narrow your choice? ({ %prefixes.keys.sort.join(', ') }, or !{ '/' ~ 'q' if !%prefixes<q> } to quit): ";
+    while prompt($prompt-text) -> $choice {
+        if 1 <= ($choice.Int // 0) <= @found {
+            $final-docee = @found[$choice.Int - 1];
+            last;
+        }
 
-    while prompt($prompt-text).words -> $word {
-        if $word  ~~ '!' or ($word ~~ 'q' and !%prefixes<q>) {
-            exit 1;
-        } elsif $word ~~ /:i $<choice> = [ @(%prefixes.keys) ] / {
-            $final-docee = %prefixes{ $<choice>.lc };
+        my @match = @found.grep(*.contains($choice));
+        if @match == 1 {
+            $final-docee = @match.first;
             last;
-        } else {
-            say "$word doesn't seem to apply here.\n";
-            next;
         }
+
+        say  "'$choice' ", @match == 0
+                ?? "doesn't seem to apply here."
+                !! "matches more than one option.";
+        next;
     }
 
+    exit 1 unless $final-docee;
+
     return $final-docee;
 }