patch 8.0.0519: character classes are not well tested
Problem: Character classes are not well tested. They can differ between
platforms.
Solution: Add tests. In the documentation make clear which classes depend
on what library function. Only use :cntrl: and :graph: for ASCII.
(Kazunobu Kuriyama, Dominique Pelle, closes #1560)
Update the documentation.
diff --git a/runtime/doc/pattern.txt b/runtime/doc/pattern.txt
index 1496604..090ca64 100644
--- a/runtime/doc/pattern.txt
+++ b/runtime/doc/pattern.txt
@@ -1085,25 +1085,27 @@
- A character class expression is evaluated to the set of characters
belonging to that character class. The following character classes
are supported:
- Name Contents ~
-*[:alnum:]* [:alnum:] ASCII letters and digits
-*[:alpha:]* [:alpha:] ASCII letters
-*[:blank:]* [:blank:] space and tab characters
-*[:cntrl:]* [:cntrl:] control characters
-*[:digit:]* [:digit:] decimal digits
-*[:graph:]* [:graph:] printable characters excluding space
-*[:lower:]* [:lower:] lowercase letters (all letters when
+ Name Func Contents ~
+*[:alnum:]* [:alnum:] isalnum ASCII letters and digits
+*[:alpha:]* [:alpha:] isalpha ASCII letters
+*[:blank:]* [:blank:] space and tab
+*[:cntrl:]* [:cntrl:] iscntrl ASCII control characters
+*[:digit:]* [:digit:] decimal digits '0' to '9'
+*[:graph:]* [:graph:] isgraph ASCII printable characters excluding
+ space
+*[:lower:]* [:lower:] (1) lowercase letters (all letters when
'ignorecase' is used)
-*[:print:]* [:print:] printable characters including space
-*[:punct:]* [:punct:] ASCII punctuation characters
-*[:space:]* [:space:] whitespace characters
-*[:upper:]* [:upper:] uppercase letters (all letters when
+*[:print:]* [:print:] (2) printable characters including space
+*[:punct:]* [:punct:] ispunct ASCII punctuation characters
+*[:space:]* [:space:] whitespace characters: space, tab, CR,
+ NL, vertical tab, form feed
+*[:upper:]* [:upper:] (3) uppercase letters (all letters when
'ignorecase' is used)
-*[:xdigit:]* [:xdigit:] hexadecimal digits
-*[:return:]* [:return:] the <CR> character
-*[:tab:]* [:tab:] the <Tab> character
-*[:escape:]* [:escape:] the <Esc> character
-*[:backspace:]* [:backspace:] the <BS> character
+*[:xdigit:]* [:xdigit:] hexadecimal digits: 0-9, a-f, A-F
+*[:return:]* [:return:] the <CR> character
+*[:tab:]* [:tab:] the <Tab> character
+*[:escape:]* [:escape:] the <Esc> character
+*[:backspace:]* [:backspace:] the <BS> character
The brackets in character class expressions are additional to the
brackets delimiting a collection. For example, the following is a
plausible pattern for a UNIX filename: "[-./[:alnum:]_~]\+" That is,
@@ -1114,6 +1116,13 @@
regexp engine. See |two-engines|. In the future these items may
work for multi-byte characters. For now, to get all "alpha"
characters you can use: [[:lower:][:upper:]].
+
+ The "Func" column shows what library function is used. The
+ implementation depends on the system. Otherwise:
+ (1) Uses islower() for ASCII and Vim builtin rules for other
+ characters when built with the |+multi_byte| feature.
+ (2) Uses Vim builtin rules
+ (3) As with (1) but using isupper()
*/[[=* *[==]*
- An equivalence class. This means that characters are matched that
have almost the same meaning, e.g., when ignoring accents. This