feat: accept functions for ignore_case and smart_case settings

Not because I see users passing functions that do particularly
interesting or useful things, but because this is the easiest way to
make Command-T look up `vim.o.ignorecase` and `vim.o.smartcase` lazily,
if the user does not provide an explicit `ignore_case` or `smart_case`
setting.

Motivated by:

- #431 (comment)

Author: wincent

doc/command-t.txt

@@ -501,11 +501,13 @@ whenever they match the search query.
 See also |commandt.setup.never_show_dot_files|.
 
                                                    *commandt.setup.ignore_case*
-                                                      boolean (default: none)
+                                          boolean or function (default: none)
 
-Ignore case when searching. When unset (which is the default), the value of
-Neovim's |'ignorecase'| setting is used instead. See also
-|commandt.setup.smart_case|.
+Either a boolean, or a function that returns a boolean, that instructs
+Command-T to ignore case when searching. When unset (which is the default),
+the value of Neovim's |'ignorecase'| setting is used instead.
+
+See also |commandt.setup.smart_case|.
 
                                            *commandt.setup.match_listing.icons*
                                           boolean or function (default: true)
@@ -667,12 +669,13 @@ output is buffered, it's possible that slightly more than `max_files` items
 may be returned.
 
                                                     *commandt.setup.smart_case*
-                                                      boolean (default: none)
+                                          boolean or function (default: none)
 
-Overrides the |commandt.setup.ignore_case| setting if the search pattern
-contains uppercase characters, forcing the match to be case-sensitive. If
-unset (which is the default), the value of Neovim's |'smartcase'| setting will
-be used instead.
+Either a boolean, or a function that returns a boolean, that instructs
+Command-T to override the |commandt.setup.ignore_case| setting if the search
+pattern contains uppercase characters, forcing the match to be case-sensitive.
+If unset (which is the default), the value of Neovim's |'smartcase'| setting
+will be used instead.
 
                                                       *commandt.setup.traverse*
                                                      string (default: 'none')

lua/wincent/commandt/init.lua

@@ -101,7 +101,16 @@ local options_spec = {
     },
     height = { kind = 'number' },
     ignore_case = {
-      kind = 'boolean',
+      kind = {
+        one_of = {
+          {
+            kind = 'boolean',
+          },
+          {
+            kind = 'function',
+          },
+        },
+      },
       optional = true,
     },
     mappings = {
@@ -237,7 +246,16 @@ local options_spec = {
     },
     selection_highlight = { kind = 'string' },
     smart_case = {
-      kind = 'boolean',
+      kind = {
+        one_of = {
+          {
+            kind = 'boolean',
+          },
+          {
+            kind = 'function',
+          },
+        },
+      },
       optional = true,
     },
     threads = {
@@ -438,7 +456,11 @@ local default_options = {
     },
   },
   height = 15,
-  ignore_case = nil, -- If nil, will infer from Neovim's `'ignorecase'`.
+
+  -- If nil, will infer from Neovim's `'ignorecase'`.
+  ignore_case = function()
+    return vim.o.ignorecase
+  end,
 
   -- Note that because of the way we merge mappings recursively, you can _add_
   -- or _replace_ a mapping easily, but to _remove_ it you have to assign it to
@@ -520,18 +542,21 @@ local default_options = {
     },
   },
   selection_highlight = 'PmenuSel',
-  smart_case = nil, -- If nil, will infer from Neovim's `'smartcase'`.
+
+  -- If nil, will infer from Neovim's `'smartcase'`.
+  smart_case = function()
+    return vim.o.smartcase
+  end,
+
   threads = nil, -- Let heuristic apply.
   traverse = 'none', -- 'file', 'pwd' or 'none'.
 }
 
 local _options = copy(default_options)
 
 -- Have to add some of these explicitly otherwise the ones with `nil` defaults
--- won't come through (eg. `ignore_case` etc).
+-- (eg. `threads`) won't come through.
 local allowed_options = concat(keys(default_options), {
-  'ignore_case',
-  'smart_case',
   'threads',
 })
 
@@ -588,14 +613,6 @@ local sanitize_options = function(options, base)
     options = merge(base, options)
   end
 
-  -- Inferred from Neovim settings if not explicitly set.
-  if options.ignore_case == nil then
-    options.ignore_case = vim.o.ignorecase
-  end
-  if options.smart_case == nil then
-    options.smart_case = vim.o.smartcase
-  end
-
   local validate = require('wincent.commandt.private.validate')
   errors = merge(errors, validate('', nil, options, options_spec, default_options))
   return options, errors

lua/wincent/commandt/private/lib.lua

@@ -4,6 +4,7 @@
 local ffi = require('ffi')
 
 local merge = require('wincent.commandt.private.merge')
+local toboolean = require('wincent.commandt.private.toboolean')
 
 local lib = {}
 
@@ -192,6 +193,12 @@ lib.matcher_new = function(scanner, options)
   if options.limit < 1 then
     error('limit must be > 0')
   end
+  if type(options.ignore_case) == 'function' then
+    options.ignore_case = toboolean(options.ignore_case())
+  end
+  if type(options.smart_case) == 'function' then
+    options.smart_case = toboolean(options.smart_case())
+  end
 
   local matcher = c.commandt_matcher_new(
     scanner,

lua/wincent/commandt/private/toboolean.lua

@@ -0,0 +1,8 @@
+-- SPDX-FileCopyrightText: Copyright 2025-present Greg Hurrell and contributors.
+-- SPDX-License-Identifier: BSD-2-Clause
+
+local function toboolean(value)
+  return not not value
+end
+
+return toboolean