Expose to_search_normalized to Lua, add test, and use in ListColumn (most useful for the `stocks` plugin)

docs/Lua API.rst

@@ -881,14 +881,23 @@ can be omitted.
   Convert a string from DF's CP437 encoding to the correct encoding for the
   DFHack console.
 
+.. warning::
+
+  When printing CP437-encoded text to the console (for example, names returned
+  from ``dfhack.TranslateName()``), use ``print(dfhack.df2console(text))`` to
+  ensure proper display on all platforms.
+
+
 * ``dfhack.utf2df(string)``
 
   Convert a string from UTF-8 to DF's CP437 encoding.
 
-**Note:** When printing CP437-encoded text to the console (for example, names
-returned from TranslateName()), use ``print(dfhack.df2console(text)`` to ensure
-proper display on all platforms.
+* ``dfhack.toSearchNormalized(string)``
 
+  Replace non-ASCII alphabetic characters in a CP437-encoded string with their
+  nearest ASCII equivalents, if possible, and returns a CP437-encoded string.
+  Note that the returned string may be longer than the input string. For
+  example, ``ä`` is replaced with ``a``, and ``æ`` is replaced with ``ae``.
 
 Gui module
 ----------

docs/changelog.txt

@@ -47,6 +47,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 - `createitem`: added an ``inspect`` subcommand to print the item and material tokens of existing items, which can be used to create additional matching items
 - `embark-assistant`: added support for searching for taller waterfalls (up to 50 z-levels tall)
 - `search`: added support for searching for names containing non-ASCII characters using their ASCII equivalents
+- `stocks`: added support for searching for items containing non-ASCII characters using their ASCII equivalents
 - `zone`: added an ``enumnick`` subcommand to assign enumerated nicknames (e.g "Hen 1", "Hen 2"...)
 - `zone`: added slaughter indication to ``uinfo`` output
 

library/LuaApi.cpp

@@ -1417,6 +1417,7 @@ static bool isMapLoaded() { return Core::getInstance().isMapLoaded(); }
 static std::string df2utf(std::string s) { return DF2UTF(s); }
 static std::string utf2df(std::string s) { return UTF2DF(s); }
 static std::string df2console(color_ostream &out, std::string s) { return DF2CONSOLE(out, s); }
+static std::string toSearchNormalized(std::string s) { return to_search_normalized(s); }
 
 #define WRAP_VERSION_FUNC(name, function) WRAPN(name, DFHack::Version::function)
 
@@ -1434,6 +1435,7 @@ static const LuaWrapper::FunctionReg dfhack_module[] = {
     WRAP(df2utf),
     WRAP(utf2df),
     WRAP(df2console),
+    WRAP(toSearchNormalized),
     WRAP_VERSION_FUNC(getDFHackVersion, dfhack_version),
     WRAP_VERSION_FUNC(getDFHackRelease, dfhack_release),
     WRAP_VERSION_FUNC(getDFHackBuildID, dfhack_build_id),

plugins/listcolumn.h

@@ -139,14 +139,14 @@ public:
     virtual void tokenizeSearch (vector<string> *dest, const string search)
     {
         if (!search.empty())
-            split_string(dest, search, " ");
+            split_string(dest, to_search_normalized(search), " ");
     }
 
     virtual bool showEntry(const ListEntry<T> *entry, const vector<string> &search_tokens)
     {
         if (!search_tokens.empty())
         {
-            string item_string = toLower(entry->text);
+            string item_string = to_search_normalized(entry->text);
             for (auto si = search_tokens.begin(); si != search_tokens.end(); si++)
             {
                 if (!si->empty() && item_string.find(*si) == string::npos &&
@@ -164,9 +164,9 @@ public:
         ListEntry<T> *prev_selected = (getDisplayListSize() > 0) ? display_list[highlighted_index] : NULL;
         display_list.clear();
 
-        search_string = toLower(search_string);
+        search_string = to_search_normalized(search_string);
         vector<string> search_tokens;
-        tokenizeSearch(&search_tokens, search_string);
+        tokenizeSearch(&search_tokens, to_search_normalized(search_string));
 
         for (size_t i = 0; i < list.size(); i++)
         {

test/encoding.lua

@@ -0,0 +1,8 @@
+function test.toSearchNormalized()
+    expect.eq(dfhack.toSearchNormalized(''), '')
+    expect.eq(dfhack.toSearchNormalized('abcd'), 'abcd')
+    expect.eq(dfhack.toSearchNormalized('ABCD'), 'abcd')
+    expect.eq(dfhack.toSearchNormalized(dfhack.utf2df('áçèîöü')), 'aceiou')
+    expect.eq(dfhack.toSearchNormalized(dfhack.utf2df('ÄÇÉÖÜÿ')), 'aceouy')
+    expect.eq(dfhack.toSearchNormalized(dfhack.utf2df('æÆ')), 'aeae')
+end