Generate simple case folding tables only if asked

Speed up mktables by not generating the simple case folding tables
unless asked to.  Previously the simple tables were generated, and then
the full tables were initialized with them, and then overwritten with
the full mappings.  This is an artifact from the fact that the data
comes to us in two files, one  with the simple mappings (among other
things), and another with the full mapping overrides.  Now, the full
tables are initialized from the first file, and the second file
overrides the full mappings.  The simple tables are not generated by
default, so this saves, copying them.

diff --git a/lib/unicore/mktables b/lib/unicore/mktables
index 376340b..c10d828 100644 (file)
--- a/lib/unicore/mktables
+++ b/lib/unicore/mktables
@@ -9025,16 +9025,16 @@ END
     $field_names[$COMMENT] = 'ISO_Comment';
     $field_names[$DECOMP_MAP] = 'Decomposition_Mapping';
     $field_names[$DECOMP_TYPE] = 'Decomposition_Type';
-    $field_names[$LOWER] = 'Simple_Lowercase_Mapping';
+    $field_names[$LOWER] = 'Lowercase_Mapping';
     $field_names[$MIRRORED] = 'Bidi_Mirrored';
     $field_names[$NAME] = 'Name';
     $field_names[$NUMERIC] = 'Numeric_Value';
     $field_names[$NUMERIC_TYPE_OTHER_DIGIT] = 'Numeric_Type';
     $field_names[$PERL_DECIMAL_DIGIT] = 'Perl_Decimal_Digit';
     $field_names[$PERL_DECOMPOSITION] = 'Perl_Decomposition_Mapping';
-    $field_names[$TITLE] = 'Simple_Titlecase_Mapping';
+    $field_names[$TITLE] = 'Titlecase_Mapping';
     $field_names[$UNICODE_1_NAME] = 'Unicode_1_Name';
-    $field_names[$UPPER] = 'Simple_Uppercase_Mapping';
+    $field_names[$UPPER] = 'Uppercase_Mapping';
 
     # Some of these need a little more explanation.  The $PERL_DECIMAL_DIGIT
     # field does not lead to an official Unicode property, but is used in
@@ -9784,26 +9784,35 @@ sub filter_arabic_shaping_line {
 
 sub setup_special_casing {
     # SpecialCasing.txt contains the non-simple case change mappings.  The
-    # simple ones are in UnicodeData.txt, and should already have been read
-    # in.
-    # This routine initializes the full mappings to the simple, then as each
-    # line is processed, it overrides the simple ones.
+    # simple ones are in UnicodeData.txt, which should already have been read
+    # in to the full property data structures, so as to initialize these with
+    # the simple ones.  Then the SpecialCasing.txt entries overwrite the ones
+    # which have different full mappings.
+
+    # This routine sees if the simple mappings are to be output, and if so,
+    # copies what has already been put into the full mapping tables, while
+    # they still contain only the simple mappings.
+
+    # The reason it is done this way is that the simple mappings are probably
+    # not going to be output, so it saves work to initialize the full tables
+    # with the simple mappings, and then overwrite those relatively few
+    # entries in them that have different full mappings, and thus skip the
+    # simple mapping tables altogether.
 
     my $file= shift;
     Carp::carp_extra_args(\@_) if main::DEBUG && @_;
 
     # For each of the case change mappings...
     foreach my $case ('lc', 'tc', 'uc') {
+        my $full = property_ref($case);
+        unless (defined $full && ! $full->is_empty) {
+            Carp::my_carp_bug("Need to process UnicodeData before SpecialCasing.  Only special casing will be generated.");
+        }
 
         # The simple version's name in each mapping merely has an 's' in front
         # of the full one's
         my $simple = property_ref('s' . $case);
-        unless (defined $simple && ! $simple->is_empty) {
-            Carp::my_carp_bug("Need to process UnicodeData before SpecialCasing.  Only special casing will be generated.");
-        }
-
-        # Initialize the full case mappings with the simple ones.
-        property_ref($case)->initialize($simple);
+        $simple->initialize($case) if $simple->to_output_map();
     }
 
     return;