fewer temporary variables

we can `return` from an inner block, even when that block is executed
somewhere else: `return` is lexical!

7 files changed, 39 insertions, 47 deletions

diff --git a/lib/MaildirIndexer/Email.rakumod b/lib/MaildirIndexer/Email.rakumod
index 4f92106..aabf185 100644
--- a/lib/MaildirIndexer/Email.rakumod
+++ b/lib/MaildirIndexer/Email.rakumod
@@ -18,11 +18,9 @@ method refs(--> Iterable) {
 
 multi split-refs(Any --> Iterable) { return () }
 multi split-refs(Str:D $str --> Iterable) {
-    my @result;
     MaildirIndexer::LogTimelineSchema::Parse::Header.log: {
-        @result = $/<refs>».Str if $str ~~ m{'<' $<refs> = (<-[<>]>+)+ % [ '>' .*? '<' ] '>' };
+        return $/<refs>».Str if $str ~~ m{'<' $<refs> = (<-[<>]>+)+ % [ '>' .*? '<' ] '>' };
     }
-    return @result;
 }
 
 method addresses (--> Iterable) {
@@ -59,11 +57,9 @@ my grammar Address {
 
 multi sub extract-addresses(Any --> Iterable) { return () }
 multi sub extract-addresses(Str:D $str --> Iterable) {
-    my @result;
     MaildirIndexer::LogTimelineSchema::Parse::Header.log: {
         with Address.parse($str) {
-            @result = $_<addr>».Str;
+            return $_<addr>».Str;
         }
     }
-    return @result;
 }
diff --git a/lib/MaildirIndexer/Index/ByAddresses.rakumod b/lib/MaildirIndexer/Index/ByAddresses.rakumod
index 40e98f9..c6cc412 100644
--- a/lib/MaildirIndexer/Index/ByAddresses.rakumod
+++ b/lib/MaildirIndexer/Index/ByAddresses.rakumod
@@ -41,7 +41,7 @@ submethod account-for(Str @addresses,Str $mailbox,Int $step) {
 }
 
 method add-mail(MaildirIndexer::Email:D $email, Str:D $mailbox --> Nil) {
-    MaildirIndexer::LogTimelineSchema::Index::Add.log: :class('ByAddresses'),:$mailbox, -> {
+    MaildirIndexer::LogTimelineSchema::Index::Add.log: :class('ByAddresses'),:$mailbox, {
         # ignore adding the same file twice, files in maildirs are
         # immutable
         return if %!addresses-for-file{ $email.path }:exists;
@@ -56,7 +56,7 @@ method add-mail(MaildirIndexer::Email:D $email, Str:D $mailbox --> Nil) {
 }
 
 method del-path(IO:D $file, Str:D $mailbox --> Nil) {
-    MaildirIndexer::LogTimelineSchema::Index::Rm.log: :class('ByAddresses'),:$mailbox, -> {
+    MaildirIndexer::LogTimelineSchema::Index::Rm.log: :class('ByAddresses'),:$mailbox, {
         # using assignment would fail when the path isn't present in
         # the hash, because it tries to assign the (undefined)
         # Array[Str] as a single element, instead of splatting it;
@@ -93,13 +93,12 @@ submethod predict-mailbox-given-addresses(@addresses) {
 }
 
 method mailbox-for-email(MaildirIndexer::Email:D $email --> Str) {
-    my Str $result;
-    MaildirIndexer::LogTimelineSchema::Index::Find.log: :class('ByAddresses'), -> {
+    MaildirIndexer::LogTimelineSchema::Index::Find.log: :class('ByAddresses'), {
         my %prediction = self.predict-mailbox-given-addresses($email.addresses);
 
         my @most-probable-mailboxes = %prediction.pairs.sort(*.value);
 
-        if @most-probable-mailboxes -> $_ { $result = .[*-1].key }
+        if @most-probable-mailboxes -> $_ { return .[*-1].key }
+        else { return Nil }
     }
-    return $result;
 }
diff --git a/lib/MaildirIndexer/Index/ByRef.rakumod b/lib/MaildirIndexer/Index/ByRef.rakumod
index 6e5b7f5..3a5ebdb 100644
--- a/lib/MaildirIndexer/Index/ByRef.rakumod
+++ b/lib/MaildirIndexer/Index/ByRef.rakumod
@@ -13,7 +13,7 @@ method dump() {
 }
 
 method add-mail(MaildirIndexer::Email:D $email, Str:D $mailbox --> Nil) {
-    MaildirIndexer::LogTimelineSchema::Index::Add.log: :class('ByRef'),:$mailbox, -> {
+    MaildirIndexer::LogTimelineSchema::Index::Add.log: :class('ByRef'),:$mailbox, {
         # ignore adding the same file twice, files in maildirs are
         # immutable
         return if %!id-for-file{ $email.path }:exists;
@@ -26,7 +26,7 @@ method add-mail(MaildirIndexer::Email:D $email, Str:D $mailbox --> Nil) {
 }
 
 method del-path(IO:D $file, Str:D $mailbox --> Nil) {
-    MaildirIndexer::LogTimelineSchema::Index::Rm.log: :class('ByRef'),:$mailbox, -> {
+    MaildirIndexer::LogTimelineSchema::Index::Rm.log: :class('ByRef'),:$mailbox, {
         my $id = %!id-for-file{ $file.path }:delete or return;
         with %!mailboxes-for-id{ $id } -> $boxes {
             $boxes{$mailbox}:delete;
@@ -36,11 +36,10 @@ method del-path(IO:D $file, Str:D $mailbox --> Nil) {
 }
 
 method mailbox-for-email(MaildirIndexer::Email:D $email --> Str) {
-    my Str $result;
-    MaildirIndexer::LogTimelineSchema::Index::Find.log: :class('ByRef'), -> {
+    MaildirIndexer::LogTimelineSchema::Index::Find.log: :class('ByRef'), {
         for |$email.refs() -> $ref {
-            with %!mailboxes-for-id{$ref} { $result = .keys.sort.[0] }
+            with %!mailboxes-for-id{$ref} { return .keys.sort.[0] }
         }
+        return Nil;
     }
-    return $result;
 }
diff --git a/lib/MaildirIndexer/Parser.rakumod b/lib/MaildirIndexer/Parser.rakumod
index 407078d..1762e58 100644
--- a/lib/MaildirIndexer/Parser.rakumod
+++ b/lib/MaildirIndexer/Parser.rakumod
@@ -61,34 +61,32 @@ my class Message-actions {
 }
 
 multi parse-email(IO::Path:D $p --> MaildirIndexer::Email) is export {
-    my MaildirIndexer::Email $result;
-    MaildirIndexer::LogTimelineSchema::Parse::Email::File.log: :file($p.path), -> {
+    MaildirIndexer::LogTimelineSchema::Parse::Email::File.log: :file($p.path), {
         # as of 2019,11, `slurp` replaces all \r\n with \n ??
-        $result = parse-email($p.slurp(:enc<utf8-c8>), path => $p);
+        return parse-email($p.slurp(:enc<utf8-c8>), path => $p);
     }
-    return $result;
 }
 
 multi parse-email(IO::Path:D $p, :$headers-only! --> MaildirIndexer::Email) is export {
-    my MaildirIndexer::Email $result;
-    MaildirIndexer::LogTimelineSchema::Parse::Email::File.log: :file($p.path), -> {
-        my IO::Handle $h = $p.open(
+    # due to a bug, we can't put that LEAVE inside the inner block;
+    # see https://github.com/rakudo/rakudo/issues/2380
+    my IO::Handle $h; LEAVE { .close with $h };
+    MaildirIndexer::LogTimelineSchema::Parse::Email::File.log: :file($p.path), {
+        $h = $p.open(
                 :enc<utf8-c8>,
                 :nl-in(@separators),
                 :!chomp,
         );
-        $result = parse-email(
+        return parse-email(
             $h.lines()[0],
             path => $p,
         );
-        $h.close();
     }
-    return $result;
 }
 
 multi parse-email(IO::Socket::Async:D $s --> MaildirIndexer::Email) is export {
-    my MaildirIndexer::Email $result;
-    MaildirIndexer::LogTimelineSchema::Parse::Email::Socket.log: -> {
+    MaildirIndexer::LogTimelineSchema::Parse::Email::Socket.log: {
+        my MaildirIndexer::Email $result;
         my $string;
         react {
             whenever $s.Supply(:enc<utf8-c8>) {
@@ -99,17 +97,18 @@ multi parse-email(IO::Socket::Async:D $s --> MaildirIndexer::Email) is export {
                 $result = parse-email($string) and done;
             }
         }
+        return $result;
     }
-    return $result;
 }
 
 multi parse-email(Str:D $email-str, :$path = IO --> MaildirIndexer::Email) is export {
-    my MaildirIndexer::Email $result;
-    MaildirIndexer::LogTimelineSchema::Parse::Email::Str.log: -> {
-        CATCH { warn $_; return Nil };
+    MaildirIndexer::LogTimelineSchema::Parse::Email::Str.log: {
+        CATCH { return .fail };
         with Message.parse($email-str,:actions(Message-actions.new(:$path))) {
-            $result = .made;
+            return .made;
+        }
+        else {
+            return Nil;
         }
     }
-    return $result;
 }
diff --git a/lib/MaildirIndexer/ScanDir.rakumod b/lib/MaildirIndexer/ScanDir.rakumod
index f0ea0b7..4d6230d 100644
--- a/lib/MaildirIndexer/ScanDir.rakumod
+++ b/lib/MaildirIndexer/ScanDir.rakumod
@@ -7,7 +7,7 @@ sub scan-dir(*@paths --> Supply) is export {
     supply {
         my %watched-dirs;
 
-        CATCH { when X::IO { }; default { warn $_; done } }
+        CATCH { when X::IO { }; default { warn .gist; done } }
 
         sub start-watching(IO::Path $dir) {
             %watched-dirs{$dir.Str} = True;
diff --git a/lib/MaildirIndexer/Store.rakumod b/lib/MaildirIndexer/Store.rakumod
index 27ec915..66ec086 100644
--- a/lib/MaildirIndexer/Store.rakumod
+++ b/lib/MaildirIndexer/Store.rakumod
@@ -19,18 +19,18 @@ method dump(--> Nil) {
 method start(--> Nil) {
     for ^$.workers {
         start react {
-            CATCH { warn $_ };
+            CATCH { warn .gist };
             whenever $.file-channel -> $file {
                 when $file ~~ MaildirIndexer::ScanDir::End {
                     MaildirIndexer::LogTimelineSchema::Scan::End.log();
                 }
                 when $file ~~ :e & :f {
-                    MaildirIndexer::LogTimelineSchema::Store::Add.log: :file($file.path), -> {
+                    MaildirIndexer::LogTimelineSchema::Store::Add.log: :file($file.path), {
                         self.add-file($file);
                     }
                 }
                 when $file ~~ :!e {
-                    MaildirIndexer::LogTimelineSchema::Store::Rm.log: :file($file.path), -> {
+                    MaildirIndexer::LogTimelineSchema::Store::Rm.log: :file($file.path), {
                         self.del-file($file);
                     }
                 }
@@ -40,9 +40,9 @@ method start(--> Nil) {
 }
 
 method add-file(IO:D $file --> Nil) {
-    my $mailbox = mailbox-from-path($file.path) or return;
-    my $email = parse-email($file,:headers-only) or return;
-    CATCH { warn $_ };
+    my Str $mailbox = mailbox-from-path($file.path) or return;
+    my MaildirIndexer::Email $email = parse-email($file,:headers-only) or return;
+    CATCH { warn .gist; return };
     $!lock.protect: {
         .add-mail($email,$mailbox) for @!indices;
     }
@@ -58,15 +58,14 @@ method del-file(IO:D $file --> Nil) {
 }
 
 method mailbox-for-email(MaildirIndexer::Email:D $email --> Str) {
-    my Str $result;
     MaildirIndexer::LogTimelineSchema::Store::Find.log: {
         $!lock.protect: {
             for @!indices -> $index {
-                with $index.mailbox-for-email($email) { $result = $_; last };
+                with $index.mailbox-for-email($email) { return $_ };
             }
         }
+        return Nil;
     }
-    return $result;
 }
 
 sub mailbox-from-path(Str() $path --> Str) {
diff --git a/t/store.t b/t/store.t
index d5b2502..8544442 100644
--- a/t/store.t
+++ b/t/store.t
@@ -42,7 +42,7 @@ subtest 'finding' => {
 
     is-deeply(
         @responses,
-        $['1','2','1',Str],
+        $['1','2','1',Nil],
         'indexes are consulted until a defined value',
     );
 }