Add trim_selections primitive

doc/pages/keys.asciidoc

@@ -351,6 +351,9 @@ is a sequence of non whitespace characters
     convert spaces to tabs in current selections, uses the buffer tabstop
     option or the count parameter for tabstop
 
+*_*::
+    trim selections
+
 *<a-">*::
     rotate selections content, if specified, the count groups selections,
     so the following command

src/normal.cc

@@ -1618,6 +1618,22 @@ void spaces_to_tabs(Context& context, NormalParams params)
         SelectionList{ buffer, std::move(spaces) }.insert("\t"_str, InsertMode::Replace);
 }
 
+void trim_selections(Context& context, NormalParams)
+{
+    auto& buffer = context.buffer();
+    for (auto& sel : context.selections())
+    {
+        auto beg = buffer.iterator_at(sel.min());
+        auto end = buffer.iterator_at(sel.max());
+        while (beg != end and is_blank(*beg))
+            ++beg;
+        while (beg != end and is_blank(*end))
+            --end;
+        sel.min() = beg.coord();
+        sel.max() = end.coord();
+    }
+}
+
 SelectionList read_selections_from_register(char reg, Context& context)
 {
     if (not is_basic_alpha(reg) and reg != '^')
@@ -2166,6 +2182,8 @@ static const HashMap<Key, NormalCmd, MemoryDomain::Undefined, KeymapBackend> key
     { {'@'}, {"convert tabs to spaces in selections", tabs_to_spaces} },
     { {alt('@')}, {"convert spaces to tabs in selections", spaces_to_tabs} },
 
+    { {'_'}, {"trim selections", trim_selections} },
+
     { {'C'}, {"copy selection on next lines", copy_selections_on_next_lines<Forward>} },
     { {alt('C')}, {"copy selection on previous lines", copy_selections_on_next_lines<Backward>} },
 

test/normal/trim/cmd

@@ -0,0 +1 @@
+%<a-s>_<a-">

test/normal/trim/in

@@ -0,0 +1,3 @@
+line 1
+  line 2
+    line 3

test/normal/trim/out

@@ -0,0 +1,3 @@
+line 3
+  line 1
+    line 2

test/normal/trim/table/cmd

@@ -0,0 +1 @@
+_

test/normal/trim/table/in

@@ -0,0 +1,4 @@
+|       |       |        |                |
+|:------|------:|:------:|----------------|
+|%(foo )|%( bar)|%( qux )|%( pop )%( hip )|
+%(   kakoune   )

test/normal/trim/table/selections

@@ -0,0 +1 @@
+foo:bar:qux:pop:hip:kakoune