Make Date.truncated-to a lot faster

- upto 1.6x as fast for truncating to week - upto 15x as fast for truncating to month - upto 10x as fast for truncating to year Also remove now unneeded !truncate-ymd method.
rakudo · Jan 28, 2021 · c9ac5d9 · c9ac5d9
1 parent e6c0b5e
commit c9ac5d9
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Showing 2 changed files with 26 additions and 19 deletions.
diff --git a/src/core.c/Date.pm6 b/src/core.c/Date.pm6
@@ -217,9 +217,32 @@ my class Date does Dateish {
         )
     }
 
-    method truncated-to(Cool $unit --> Date:D) {
-        self!clone-without-validating(
-          |self!truncate-ymd(self!VALID-UNIT($unit)));
+    method truncated-to(Date:D: str $unit --> Date:D) {
+        my $truncated := nqp::clone(self);
+        my $what      := self.WHAT;
+        nqp::bindattr_i($truncated,$what,'$!daycount',0);
+        nqp::if(
+          nqp::eqat($unit,'week',0),
+          ($truncated := $truncated.move-by-unit(
+            'day',
+            nqp::sub_i(1,$truncated.day-of-week)
+          )),
+          nqp::stmts(
+            nqp::bindattr_i($truncated,$what,'$!day',1),
+            nqp::unless(
+              nqp::eqat($unit,'month',0),
+              nqp::stmts(
+                nqp::bindattr_i($truncated,$what,'$!month',1),
+                nqp::unless(
+                  nqp::eqat($unit,'year',0),
+                  die "Cannot truncate {self.^name} object to '$unit'"
+                )
+              )
+            )
+          )
+        );
+
+        $truncated
     }
 
     # workhorse method for moving a Date

diff --git a/src/core.c/Dateish.pm6 b/src/core.c/Dateish.pm6
@@ -202,22 +202,6 @@ my role Dateish {
           ?? "More than one time unit supplied"
           !! die "No time unit supplied";
     }
-
-    method !truncate-ymd(Cool:D $unit, %parts? is copy) {
-        if $unit eq 'week' | 'weeks' {
-            my $new-dc = self.daycount - self.day-of-week + 1;
-            self!ymd-from-daycount($new-dc,
-              %parts<year>,%parts<month>,%parts<day>);
-        }
-        elsif $unit eq 'day' | 'days' {
-            # no-op
-        }
-        else { # $unit eq 'month' | 'months' | 'year' | 'years'
-            %parts<day>   = 1;
-            %parts<month> = 1 if $unit eq 'year' | 'years';
-        }
-        %parts;
-    }
 }
 
 # =begin pod