feat(ex.location): the new component to show cursor location

.

README.md

@@ -11,6 +11,7 @@ for `lualine.nvim` with additional components.
  - [🧩 Provided components](#provided-components)
     - [ex.spellcheck](#exspellcheck)
     - [ex.cwd](#excwd)
+    - [ex.location](#exlocation)
     - [ex.relative_filename](#exrelative_filename)
     - [ex.git.branch](#exgitbranch)
     - [ex.lsp.single](#exlspsingle)
@@ -137,6 +138,34 @@ sections = {
 The absolute value of the {depth} will be decreased until the length of the path becomes less then
 {max_length}.
 
+### ex.location
+
+This component shows the current cursor position in configurable format. Comparing to the default
+`location` component, this component can show total number of lines, and may be flexibly configured.
+
+| pattern | example |
+|:---:|:---:|
+| `'%2C:%-3L/%T'` | <img height=18 alt="ex location" src="https://github.com/dokwork/lualine-ex/assets/6939832/743ffc33-a5f4-4f95-9204-e217fa9cdbf7"> |
+| `'%3L:%-2C'` | <img  height=18  alt="ex location-2" src="https://github.com/dokwork/lualine-ex/assets/6939832/2e9dfa90-7363-4a99-a8d1-c1cc9033d5f7"> |
+
+
+```lua
+sections = {
+  lualine_a = {
+    {
+      'ex.location',
+
+      -- The pattern to show the cursor position. Here three possible specifiers:
+      --  'L' means 'line' - the number of the line where is the cursor now;
+      --  'C' means 'column' - the number of the virtual column where is the cursor now;
+      --  'T' means 'total' - the total count of lines in the current buffer;
+      -- Every specifier can be used in similar maner to %d in the {string.format} function.
+      -- The pattern similar to the default 'location' component is '%3L:%-2C'
+      pattern = '%2C:%-3L/%T'
+    }
+  }
+}
+```
 
 ### ex.relative_filename
 

lua/lualine/components/ex/location.lua

@@ -0,0 +1,31 @@
+local log = require('plenary.log').new({ plugin = 'ex.location' })
+
+local Location = require('lualine.ex.component'):extend({
+    pattern = '%2C:%-3L/%T',
+})
+
+function Location:post_init()
+    self.__substitutions = {}
+    self.__pattern = string.gsub(self.options.pattern, '(%%%-?%d*[LCT]+)', function(template)
+        return string.gsub(template, '([LCT])', function(value)
+            table.insert(self.__substitutions, value)
+            return 'd'
+        end)
+    end)
+    log.debug(self.__substitutions)
+    log.debug(self.__pattern)
+end
+
+function Location:update_status()
+    local values = {
+        L = vim.fn.line('.'),
+        C = vim.fn.virtcol('.'),
+        T = vim.fn.line('$'),
+    }
+    local substitutions = vim.tbl_map(function(key)
+        return values[key]
+    end, self.__substitutions)
+    return string.format(self.__pattern, unpack(substitutions))
+end
+
+return Location

tests/components/location_spec.lua

@@ -0,0 +1,47 @@
+local l = require('tests.ex.lualine')
+local t = require('tests.ex.busted') --:ignore_all_tests()
+
+local eq = assert.are.equal
+
+local orig = {
+    line = vim.fn.line,
+    virtcol = vim.fn.virtcol,
+}
+local mock = {
+    line = {},
+    virtcol = {},
+}
+
+local component_name = 'ex.location'
+describe(component_name, function()
+    before_each(function()
+        vim.fn.line = function(arg)
+            return mock.line[arg]
+        end
+        vim.fn.virtcol = function(arg)
+            return mock.virtcol[arg]
+        end
+    end)
+
+    after_each(function()
+        vim.fn.line = orig.line
+        vim.fn.virtcol = orig.virtcol
+    end)
+
+    describe('default patter', function()
+        it('should show {line}:{column}/{total}', function()
+            mock.virtcol['.'] = 11
+            mock.line['.'] = 222
+            mock.line['$'] = 3333
+            local component = l.render_component(component_name)
+            eq('11:222/3333', component)
+        end)
+        it('should fill numbers by space', function()
+            mock.virtcol['.'] = 1
+            mock.line['.'] = 2
+            mock.line['$'] = 3
+            local component = l.render_component(component_name)
+            eq(' 1:2  /3', component)
+        end)
+    end)
+end)