Add buffer -matching switch

src/buffer_manager.cc

@@ -7,6 +7,7 @@
 #include "file.hh"
 #include "ranges.hh"
 #include "string.hh"
+#include "regex.hh"
 
 namespace Kakoune
 {
@@ -79,6 +80,24 @@ Buffer& BufferManager::get_buffer(StringView name)
     return *res;
 }
 
+Buffer* BufferManager::get_buffer_matching_ifp(const Regex& regex)
+{
+    for (auto& buf : m_buffers | reverse())
+    {
+        if (StringView name = buf->name(); regex_match(name.begin(), name.end(), regex))
+            return buf.get();
+    }
+    return nullptr;
+}
+
+Buffer& BufferManager::get_buffer_matching(const Regex& regex)
+{
+    Buffer* res = get_buffer_matching_ifp(regex);
+    if (not res)
+        throw runtime_error{format("no buffer matching '{}'", regex.str())};
+    return *res;
+}
+
 Buffer& BufferManager::get_first_buffer()
 {
     if (all_of(m_buffers, [](auto& b) { return (b->flags() & Buffer::Flags::Debug); }))

src/buffer_manager.hh

@@ -28,6 +28,9 @@ public:
     Buffer* get_buffer_ifp(StringView name);
     Buffer& get_buffer(StringView name);
 
+    Buffer* get_buffer_matching_ifp(const Regex& regex);
+    Buffer& get_buffer_matching(const Regex& regex);
+
     void arrange_buffers(ConstArrayView<String> first_ones);
 
     Buffer& get_first_buffer();

src/commands.cc

@@ -847,13 +847,17 @@ const CommandDesc buffer_cmd = {
     "buffer",
     "b",
     "buffer <name>: set buffer to edit in current client",
-    single_param,
+    {
+        { { "matching", { {}, "treat the argument as a regex" } } },
+        ParameterDesc::Flags::None, 1, 1
+    },
     CommandFlags::None,
     CommandHelper{},
     make_completer(menu(complete_buffer_name<true>)),
     [](const ParametersParser& parser, Context& context, const ShellContext&)
     {
-        Buffer& buffer = BufferManager::instance().get_buffer(parser[0]);
+        Buffer& buffer = parser.get_switch("matching") ? BufferManager::instance().get_buffer_matching(Regex{parser[0]})
+                                                       : BufferManager::instance().get_buffer(parser[0]);
         if (&buffer != &context.buffer())
         {
             context.push_jump();