feat(vim.version): more coercion with strict=false

Problem:
"tmux 3.2a" (output from "tmux -V") is not parsed easily.

Solution:
With `strict=false`, discard everything before the first digit.

- rename Semver => Version
- rename vim.version.version() => vim.version._version()
- rename matches() => has()
- remove `opts` from cmp()

6 files changed, 373 insertions, 209 deletions

diff --git a/runtime/autoload/provider/clipboard.vim b/runtime/autoload/provider/clipboard.vim
index 98c80f1843..6d238ddb55 100644
--- a/runtime/autoload/provider/clipboard.vim
+++ b/runtime/autoload/provider/clipboard.vim
@@ -145,8 +145,8 @@ function! provider#clipboard#Executable() abort
     let s:paste['*'] = s:paste['+']
     return 'termux-clipboard'
   elseif !empty($TMUX) && executable('tmux')
-    let ver = matchlist(systemlist(['tmux', '-V'])[0], '\vtmux %(next-)?(\d+)\.(\d+)')
-    if len(ver) >= 3 && (ver[1] > 3 || (ver[1] == 3 && ver[2] >= 2))
+    let tmux_v = v:lua.vim.version.parse(system(['tmux', '-V']))
+    if !empty(tmux_v) && !v:lua.vim.version.lt(tmux_v, [3,2,0])
       let s:copy['+'] = ['tmux', 'load-buffer', '-w', '-']
     else
       let s:copy['+'] = ['tmux', 'load-buffer', '-']
diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index e7dcc79f4a..cec3c1303f 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -782,9 +782,6 @@ vim.api.{func}({...})                                                *vim.api*
     Example: call the "nvim_get_current_line()" API function: >lua
         print(tostring(vim.api.nvim_get_current_line()))
 
-vim.version()                                                    *vim.version*
-    Gets the version of the current Nvim build.
-
 vim.in_fast_event()                                      *vim.in_fast_event()*
     Returns true if the code is executing as part of a "fast" event handler,
     where most of the API is disabled. These are low-level events (e.g.
@@ -1391,8 +1388,7 @@ deprecate({name}, {alternative}, {version}, {plugin}, {backtrace})
     Parameters: ~
       • {name}         string Deprecated feature (function, API, etc.).
       • {alternative}  (string|nil) Suggested alternative feature.
-      • {version}      string Version when the deprecated function will be
-                       removed.
+      • {version}      string Version when the deprecated function will be removed.
       • {plugin}       string|nil Name of the plugin that owns the deprecated
                        feature. Defaults to "Nvim".
       • {backtrace}    boolean|nil Prints backtrace. Defaults to true.
@@ -2533,67 +2529,179 @@ trust({opts})                                             *vim.secure.trust()*
 ==============================================================================
 Lua module: version                                              *lua-version*
 
-cmp({v1}, {v2}, {opts})                                    *vim.version.cmp()*
-    Compares two strings ( `v1` and `v2` ) in semver format.
+
+The `vim.version` module provides functions for comparing versions and
+ranges conforming to the
+
+https://semver.org
+
+spec. Plugins, and plugin managers, can use this to check available tools
+and dependencies on the current system.
+
+Example: >lua
+
+  local v = vim.version.parse(vim.fn.system({'tmux', '-V'}), {strict=false})
+  if vim.version.gt(v, {3, 2, 0}) then
+    -- ...
+  end
+
+<
+
+*vim.version()* returns the version of the current Nvim process.
+
+VERSION RANGE SPEC *version-range*
+
+A version "range spec" defines a semantic version range which can be
+tested against a version, using |vim.version.range()|.
+
+Supported range specs are shown in the following table. Note: suffixed
+versions (1.2.3-rc1) are not matched. >
+
+  1.2.3             is 1.2.3
+  =1.2.3            is 1.2.3
+  >1.2.3            greater than 1.2.3
+  <1.2.3            before 1.2.3
+  >=1.2.3           at least 1.2.3
+  ~1.2.3            is >=1.2.3 <1.3.0       "reasonably close to 1.2.3"
+  ^1.2.3            is >=1.2.3 <2.0.0       "compatible with 1.2.3"
+  ^0.2.3            is >=0.2.3 <0.3.0       (0.x.x is special)
+  ^0.0.1            is =0.0.1               (0.0.x is special)
+  ^1.2              is >=1.2.0 <2.0.0       (like ^1.2.0)
+  ~1.2              is >=1.2.0 <1.3.0       (like ~1.2.0)
+  ^1                is >=1.0.0 <2.0.0       "compatible with 1"
+  ~1                same                    "reasonably close to 1"
+  1.x               same
+  1.*               same
+  1                 same
+  *                 any version
+  x                 same
+
+  1.2.3 - 2.3.4     is >=1.2.3 <=2.3.4
+
+  Partial right: missing pieces treated as x (2.3 => 2.3.x).
+  1.2.3 - 2.3       is >=1.2.3 <2.4.0
+  1.2.3 - 2         is >=1.2.3 <3.0.0
+
+  Partial left: missing pieces treated as 0 (1.2 => 1.2.0).
+  1.2 - 2.3.0       is 1.2.0 - 2.3.0
+
+<
+
+cmp({v1}, {v2})                                            *vim.version.cmp()*
+    Parses and compares two version version objects (the result of
+    |vim.version.parse()|, or specified literally as a `{major, minor, patch}`
+    tuple, e.g. `{1, 0, 3}`).
+
+    Example: >lua
+
+       if vim.version.cmp({1,0,3}, {0,2,1}) == 0 then
+         -- ...
+       end
+       local v1 = vim.version.parse('1.0.3-pre')
+       local v2 = vim.version.parse('0.2.1')
+       if vim.version.cmp(v1, v2) == 0 then
+         -- ...
+       end
+<
+
+    Note:
+        Per semver, build metadata is ignored when comparing two
+        otherwise-equivalent versions.
 
     Parameters: ~
-      • {v1}    (string) Version.
-      • {v2}    (string) Version to compare with v1.
-      • {opts}  (table|nil) Optional keyword arguments:
-                • strict (boolean): see `semver.parse` for details. Defaults
-                  to false.
+      • {v1}  Version|number[] Version object.
+      • {v2}  Version|number[] Version to compare with `v1` .
 
     Return: ~
-        (integer) `-1` if `v1 < v2`, `0` if `v1 == v2`, `1` if `v1 > v2`.
+        (integer) -1 if `v1 < v2`, 0 if `v1 == v2`, 1 if `v1 > v2`.
 
 eq({v1}, {v2})                                              *vim.version.eq()*
-    Returns `true` if `v1` are `v2` are equal versions.
+    Returns `true` if the given versions are equal.
 
     Parameters: ~
-      • {v1}  (string)
-      • {v2}  (string)
+      • {v1}  Version|number[]
+      • {v2}  Version|number[]
 
     Return: ~
         (boolean)
 
 gt({v1}, {v2})                                              *vim.version.gt()*
-    Returns `true` if `v1` is greater than `v2` .
+    Returns `true` if `v1 > v2` .
 
     Parameters: ~
-      • {v1}  (string)
-      • {v2}  (string)
+      • {v1}  Version|number[]
+      • {v2}  Version|number[]
 
     Return: ~
         (boolean)
 
+last({versions})                                          *vim.version.last()*
+    TODO: generalize this, move to func.lua
+
+    Parameters: ~
+      • {versions}  Version []
+
+    Return: ~
+        Version ?|ni
+
 lt({v1}, {v2})                                              *vim.version.lt()*
-    Returns `true` if `v1` is less than `v2` .
+    Returns `true` if `v1 < v2` .
 
     Parameters: ~
-      • {v1}  (string)
-      • {v2}  (string)
+      • {v1}  Version|number[]
+      • {v2}  Version|number[]
 
     Return: ~
         (boolean)
 
 parse({version}, {opts})                                 *vim.version.parse()*
-    Parses a semantic version string.
-
-    Ignores leading "v" and surrounding whitespace, e.g. "
-    v1.0.1-rc1+build.2", "1.0.1-rc1+build.2", "v1.0.1-rc1+build.2" and
-    "v1.0.1-rc1+build.2 " are all parsed as: >
+    Parses a semantic version string and returns a version object which can be
+    used with other `vim.version` functions. For example "1.0.1-rc1+build.2" returns: >
 
        { major = 1, minor = 0, patch = 1, prerelease = "rc1", build = "build.2" }
 <
 
     Parameters: ~
-      • {version}  (string) Version string to be parsed.
+      • {version}  (string) Version string to parse.
       • {opts}     (table|nil) Optional keyword arguments:
-                   • strict (boolean): Default false. If `true` , no coercion is attempted on input not strictly
-                     conforming to semver v2.0.0 ( https://semver.org/spec/v2.0.0.html ). E.g. `parse("v1.2")` returns nil.
+                   • strict (boolean): Default false. If `true`, no coercion
+                     is attempted on input not conforming to semver v2.0.0. If
+                     `false`, `parse()` attempts to coerce input such as
+                     "1.0", "0-x", "tmux 3.2a" into valid versions.
 
     Return: ~
-        (table|nil) parsed_version Parsed version table or `nil` if `version`
-        is invalid.
+        (table|nil) parsed_version Version object or `nil` if input is invalid.
+
+    See also: ~
+      • # https://semver.org/spec/v2.0.0.html
+
+range({spec})                                            *vim.version.range()*
+    Parses a semver |version-range| "spec" and returns a range object: >
+
+      {
+        from: Version
+        to: Version
+        has(v: string|Version)
+      }
+<
+
+    `:has()` checks if a version is in the range (inclusive `from` , exclusive `to` ). Example: >lua
+
+      local r = vim.version.range('1.0.0 - 2.0.0')
+      print(r:has('1.9.9'))  -- true
+      print(r:has('2.0.0'))  -- false
+<
+
+    Or use cmp(), eq(), lt(), and gt() to compare `.to` and `.from` directly: >lua
+
+      local r = vim.version.range('1.0.0 - 2.0.0')
+      print(vim.version.gt({1,0,3}, r.from) and vim.version.lt({1,0,3}, r.to))
+<
+
+    Parameters: ~
+      • {spec}  string Version range "spec"
+
+    See also: ~
+      • # https://github.com/npm/node-semver#ranges
 
  vim:tw=78:ts=8:sw=4:sts=4:et:ft=help:norl:
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 5ac6db6f84..c326ae15c7 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -65,8 +65,8 @@ NEW FEATURES                                                    *news-features*
 
 The following new APIs or features were added.
 
-• Added |vim.version| for parsing and comparing version strings conforming to
-  the semver specification, see |lua-version|.
+• Added |lua-version| for parsing and comparing version strings conforming to
+  the semver specification.
 
 • A new environment variable named NVIM_APPNAME enables configuring the
   directories where Neovim should find its configuration and state files. See
diff --git a/runtime/lua/vim/version.lua b/runtime/lua/vim/version.lua
index e79acf079b..8d8b0d6da7 100644
--- a/runtime/lua/vim/version.lua
+++ b/runtime/lua/vim/version.lua
@@ -1,9 +1,59 @@
-local M = {}
+--- @defgroup lua-version
+---
+--- @brief The \`vim.version\` module provides functions for comparing versions and ranges
+--- conforming to the https://semver.org spec. Plugins, and plugin managers, can use this to check
+--- available tools and dependencies on the current system.
+---
+--- Example:
+---   <pre>lua
+---   local v = vim.version.parse(vim.fn.system({'tmux', '-V'}), {strict=false})
+---   if vim.version.gt(v, {3, 2, 0}) then
+---     -- ...
+---   end
+---   </pre>
+---
+--- \*vim.version()\* returns the version of the current Nvim process.
+---
+--- VERSION RANGE SPEC \*version-range\*
+---
+--- A version "range spec" defines a semantic version range which can be tested against a version,
+--- using |vim.version.range()|.
+---
+--- Supported range specs are shown in the following table.
+--- Note: suffixed versions (1.2.3-rc1) are not matched.
+---   <pre>
+---   1.2.3             is 1.2.3
+---   =1.2.3            is 1.2.3
+---   >1.2.3            greater than 1.2.3
+---   <1.2.3            before 1.2.3
+---   >=1.2.3           at least 1.2.3
+---   ~1.2.3            is >=1.2.3 <1.3.0       "reasonably close to 1.2.3"
+---   ^1.2.3            is >=1.2.3 <2.0.0       "compatible with 1.2.3"
+---   ^0.2.3            is >=0.2.3 <0.3.0       (0.x.x is special)
+---   ^0.0.1            is =0.0.1               (0.0.x is special)
+---   ^1.2              is >=1.2.0 <2.0.0       (like ^1.2.0)
+---   ~1.2              is >=1.2.0 <1.3.0       (like ~1.2.0)
+---   ^1                is >=1.0.0 <2.0.0       "compatible with 1"
+---   ~1                same                    "reasonably close to 1"
+---   1.x               same
+---   1.*               same
+---   1                 same
+---   *                 any version
+---   x                 same
+---
+---   1.2.3 - 2.3.4     is >=1.2.3 <=2.3.4
+---
+---   Partial right: missing pieces treated as x (2.3 => 2.3.x).
+---   1.2.3 - 2.3       is >=1.2.3 <2.4.0
+---   1.2.3 - 2         is >=1.2.3 <3.0.0
+---
+---   Partial left: missing pieces treated as 0 (1.2 => 1.2.0).
+---   1.2 - 2.3.0       is 1.2.0 - 2.3.0
+---   </pre>
 
-local LazyM = {}
-M.LazyM = LazyM
+local M = {}
 
----@class Semver
+---@class Version
 ---@field [1] number
 ---@field [2] number
 ---@field [3] number
@@ -12,14 +62,14 @@ M.LazyM = LazyM
 ---@field patch number
 ---@field prerelease? string
 ---@field build? string
-local Semver = {}
-Semver.__index = Semver
+local Version = {}
+Version.__index = Version
 
-function Semver:__index(key)
-  return type(key) == 'number' and ({ self.major, self.minor, self.patch })[key] or Semver[key]
+function Version:__index(key)
+  return type(key) == 'number' and ({ self.major, self.minor, self.patch })[key] or Version[key]
 end
 
-function Semver:__newindex(key, value)
+function Version:__newindex(key, value)
   if key == 1 then
     self.major = value
   elseif key == 2 then
@@ -31,8 +81,8 @@ function Semver:__newindex(key, value)
   end
 end
 
----@param other Semver
-function Semver:__eq(other)
+---@param other Version
+function Version:__eq(other)
   for i = 1, 3 do
     if self[i] ~= other[i] then
       return false
@@ -41,7 +91,7 @@ function Semver:__eq(other)
   return self.prerelease == other.prerelease
 end
 
-function Semver:__tostring()
+function Version:__tostring()
   local ret = table.concat({ self.major, self.minor, self.patch }, '.')
   if self.prerelease then
     ret = ret .. '-' .. self.prerelease
@@ -52,8 +102,8 @@ function Semver:__tostring()
   return ret
 end
 
----@param other Semver
-function Semver:__lt(other)
+---@param other Version
+function Version:__lt(other)
   for i = 1, 3 do
     if self[i] > other[i] then
       return false
@@ -70,21 +120,32 @@ function Semver:__lt(other)
   return (self.prerelease or '') < (other.prerelease or '')
 end
 
----@param other Semver
-function Semver:__le(other)
+---@param other Version
+function Version:__le(other)
   return self < other or self == other
 end
 
----@param version string|number[]
----@param strict? boolean Reject "1.0", "0-x" or other non-conforming version strings
----@return Semver?
-function LazyM.version(version, strict)
+--- @private
+---
+--- Creates a new Version object. Not public currently.
+---
+--- @param version string|number[]|Version
+--- @param strict? boolean Reject "1.0", "0-x", "3.2a" or other non-conforming version strings
+--- @return Version?
+function M._version(version, strict) -- Adapted from https://github.com/folke/lazy.nvim
   if type(version) == 'table' then
+    if version.major then
+      return setmetatable(vim.deepcopy(version), Version)
+    end
     return setmetatable({
       major = version[1] or 0,
       minor = version[2] or 0,
       patch = version[3] or 0,
-    }, Semver)
+    }, Version)
+  end
+
+  if not strict then -- TODO: add more "scrubbing".
+    version = version:match('%d[^ ]*')
   end
 
   local prerel = version:match('%-([^+]*)')
@@ -110,11 +171,13 @@ function LazyM.version(version, strict)
       patch = patch == '' and 0 or tonumber(patch),
       prerelease = prerel ~= '' and prerel or nil,
       build = build ~= '' and build or nil,
-    }, Semver)
+    }, Version)
   end
 end
 
----@generic T: Semver
+---TODO: generalize this, move to func.lua
+---
+---@generic T: Version
 ---@param versions T[]
 ---@return T?
 function M.last(versions)
@@ -127,13 +190,15 @@ function M.last(versions)
   return last
 end
 
----@class SemverRange
----@field from Semver
----@field to? Semver
+---@class Range
+---@field from Version
+---@field to? Version
 local Range = {}
 
----@param version string|Semver
-function Range:matches(version)
+--- @private
+---
+---@param version string|Version
+function Range:has(version)
   if type(version) == 'string' then
     ---@diagnostic disable-next-line: cast-local-type
     version = M.parse(version)
@@ -146,8 +211,32 @@ function Range:matches(version)
   end
 end
 
----@param spec string
-function LazyM.range(spec)
+--- Parses a semver |version-range| "spec" and returns a range object:
+---   <pre>
+---   {
+---     from: Version
+---     to: Version
+---     has(v: string|Version)
+---   }
+---   </pre>
+---
+--- `:has()` checks if a version is in the range (inclusive `from`, exclusive `to`). Example:
+---   <pre>lua
+---   local r = vim.version.range('1.0.0 - 2.0.0')
+---   print(r:has('1.9.9'))  -- true
+---   print(r:has('2.0.0'))  -- false
+---   </pre>
+---
+--- Or use cmp(), eq(), lt(), and gt() to compare `.to` and `.from` directly:
+---   <pre>lua
+---   local r = vim.version.range('1.0.0 - 2.0.0')
+---   print(vim.version.gt({1,0,3}, r.from) and vim.version.lt({1,0,3}, r.to))
+---   </pre>
+---
+--- @see # https://github.com/npm/node-semver#ranges
+---
+--- @param spec string Version range "spec"
+function M.range(spec) -- Adapted from https://github.com/folke/lazy.nvim
   if spec == '*' or spec == '' then
     return setmetatable({ from = M.parse('0.0.0') }, { __index = Range })
   end
@@ -158,8 +247,8 @@ function LazyM.range(spec)
     local a = spec:sub(1, hyphen - 1)
     local b = spec:sub(hyphen + 3)
     local parts = vim.split(b, '.', { plain = true })
-    local ra = LazyM.range(a)
-    local rb = LazyM.range(b)
+    local ra = M.range(a)
+    local rb = M.range(b)
     return setmetatable({
       from = ra and ra.from,
       to = rb and (#parts == 3 and rb.from or rb.to),
@@ -209,40 +298,40 @@ function LazyM.range(spec)
 end
 
 ---@private
----@param v string
+---@param v string|Version
 ---@return string
 local function create_err_msg(v)
   if type(v) == 'string' then
     return string.format('invalid version: "%s"', tostring(v))
+  elseif type(v) == 'table' and v.major then
+    return string.format('invalid version: %s', vim.inspect(v))
   end
   return string.format('invalid version: %s (%s)', tostring(v), type(v))
 end
 
----@private
---- Throws an error if `version` cannot be parsed.
----@param v string
-local function assert_version(v, opt)
-  local rv = M.parse(v, opt)
-  if rv == nil then
-    error(create_err_msg(v))
-  end
-  return rv
-end
-
---- Parses and compares two version strings.
+--- Parses and compares two version version objects (the result of |vim.version.parse()|, or
+--- specified literally as a `{major, minor, patch}` tuple, e.g. `{1, 0, 3}`).
 ---
---- semver notes:
---- - Build metadata MUST be ignored when comparing versions.
+--- Example:
+--- <pre>lua
+---   if vim.version.cmp({1,0,3}, {0,2,1}) == 0 then
+---     -- ...
+---   end
+---   local v1 = vim.version.parse('1.0.3-pre')
+---   local v2 = vim.version.parse('0.2.1')
+---   if vim.version.cmp(v1, v2) == 0 then
+---     -- ...
+---   end
+--- </pre>
 ---
----@param v1 string Version.
----@param v2 string Version to compare with v1.
----@param opts table|nil Optional keyword arguments:
----                      - strict (boolean):  see `version.parse` for details. Defaults to false.
----@return integer `-1` if `v1 < v2`, `0` if `v1 == v2`, `1` if `v1 > v2`.
-function M.cmp(v1, v2, opts)
-  opts = opts or { strict = false }
-  local v1_parsed = assert_version(v1, opts)
-  local v2_parsed = assert_version(v2, opts)
+--- @note Per semver, build metadata is ignored when comparing two otherwise-equivalent versions.
+---
+---@param v1 Version|number[] Version object.
+---@param v2 Version|number[] Version to compare with `v1`.
+---@return integer -1 if `v1 < v2`, 0 if `v1 == v2`, 1 if `v1 > v2`.
+function M.cmp(v1, v2)
+  local v1_parsed = assert(M._version(v1), create_err_msg(v1))
+  local v2_parsed = assert(M._version(v2), create_err_msg(v1))
   if v1_parsed == v2_parsed then
     return 0
   end
@@ -252,58 +341,50 @@ function M.cmp(v1, v2, opts)
   return -1
 end
 
---- Parses a semantic version string.
----
---- Ignores leading "v" and surrounding whitespace, e.g. " v1.0.1-rc1+build.2",
---- "1.0.1-rc1+build.2", "v1.0.1-rc1+build.2" and "v1.0.1-rc1+build.2 " are all parsed as:
---- <pre>
----   { major = 1, minor = 0, patch = 1, prerelease = "rc1", build = "build.2" }
---- </pre>
----
----@param version string Version string to be parsed.
----@param opts table|nil Optional keyword arguments:
----                      - strict (boolean):  Default false. If `true`, no coercion is attempted on
----                      input not strictly conforming to semver v2.0.0
----                      (https://semver.org/spec/v2.0.0.html). E.g. `parse("v1.2")` returns nil.
----@return table|nil parsed_version Parsed version table or `nil` if `version` is invalid.
-function M.parse(version, opts)
-  if type(version) ~= 'string' then
-    error(create_err_msg(version))
-  end
-  opts = opts or { strict = false }
-
-  if opts.strict then
-    return LazyM.version(version, true)
-  end
-
-  version = vim.trim(version) -- TODO: add more "scrubbing".
-  return LazyM.version(version, false)
-end
-
----Returns `true` if `v1` are `v2` are equal versions.
----@param v1 string
----@param v2 string
+---Returns `true` if the given versions are equal.
+---@param v1 Version|number[]
+---@param v2 Version|number[]
 ---@return boolean
 function M.eq(v1, v2)
   return M.cmp(v1, v2) == 0
 end
 
----Returns `true` if `v1` is less than `v2`.
----@param v1 string
----@param v2 string
+---Returns `true` if `v1 < v2`.
+---@param v1 Version|number[]
+---@param v2 Version|number[]
 ---@return boolean
 function M.lt(v1, v2)
   return M.cmp(v1, v2) == -1
 end
 
----Returns `true` if `v1` is greater than `v2`.
----@param v1 string
----@param v2 string
+---Returns `true` if `v1 > v2`.
+---@param v1 Version|number[]
+---@param v2 Version|number[]
 ---@return boolean
 function M.gt(v1, v2)
   return M.cmp(v1, v2) == 1
 end
 
+--- Parses a semantic version string and returns a version object which can be used with other
+--- `vim.version` functions. For example "1.0.1-rc1+build.2" returns:
+--- <pre>
+---   { major = 1, minor = 0, patch = 1, prerelease = "rc1", build = "build.2" }
+--- </pre>
+---
+--- @see # https://semver.org/spec/v2.0.0.html
+---
+---@param version string Version string to parse.
+---@param opts table|nil Optional keyword arguments:
+---                      - strict (boolean):  Default false. If `true`, no coercion is attempted on
+---                      input not conforming to semver v2.0.0. If `false`, `parse()` attempts to
+---                      coerce input such as "1.0", "0-x", "tmux 3.2a" into valid versions.
+---@return table|nil parsed_version Version object or `nil` if input is invalid.
+function M.parse(version, opts)
+  assert(type(version) == 'string', create_err_msg(version))
+  opts = opts or { strict = false }
+  return M._version(version, opts.strict)
+end
+
 setmetatable(M, {
   __call = function()
     return vim.fn.api_info().version
diff --git a/test/functional/lua/version_spec.lua b/test/functional/lua/version_spec.lua
index 2fb02795b2..014fea5272 100644
--- a/test/functional/lua/version_spec.lua
+++ b/test/functional/lua/version_spec.lua
@@ -6,11 +6,8 @@ local exec_lua = helpers.exec_lua
 local matches = helpers.matches
 local pcall_err = helpers.pcall_err
 
-local version = require('vim.version')
-local Semver = version.LazyM
-
 local function v(ver)
-  return Semver.version(ver)
+  return vim.version._version(ver)
 end
 
 describe('version', function()
@@ -20,13 +17,13 @@ describe('version', function()
     eq({ major = 42, minor = 3, patch = 99 }, exec_lua("return vim.version.parse('v42.3.99')"))
   end)
 
-  describe('lazy semver version', function()
+  describe('_version()', function()
     local tests = {
       ['v1.2.3'] = { major = 1, minor = 2, patch = 3 },
       ['v1.2'] = { major = 1, minor = 2, patch = 0 },
       ['v1.2.3-prerelease'] = { major = 1, minor = 2, patch = 3, prerelease = 'prerelease' },
       ['v1.2-prerelease'] = { major = 1, minor = 2, patch = 0, prerelease = 'prerelease' },
-      ['v1.2.3-prerelease+build'] = { major = 1, minor = 2, patch = 3, prerelease = 'prerelease', build = "build" },
+      ['v1.2.3-prerelease+build'] = { major = 1, minor = 2, patch = 3, prerelease = 'prerelease', build = 'build' },
       ['1.2.3+build'] = { major = 1, minor = 2, patch = 3, build = 'build' },
     }
     for input, output in pairs(tests) do
@@ -36,7 +33,7 @@ describe('version', function()
     end
   end)
 
-  describe('lazy semver range', function()
+  describe('range', function()
     local tests = {
       ['1.2.3'] = { from = { 1, 2, 3 }, to = { 1, 2, 4 } },
       ['1.2'] = { from = { 1, 2, 0 }, to = { 1, 3, 0 } },
@@ -64,51 +61,34 @@ describe('version', function()
     for input, output in pairs(tests) do
       output.from = v(output.from)
       output.to = output.to and v(output.to)
+      local range = vim.version.range(input)
 
-      local range = Semver.range(input)
       it('parses ' .. input, function()
         eq(output, range)
       end)
 
       it('[from] in range ' .. input, function()
-        assert(range:matches(output.from))
+        assert(range:has(output.from))
       end)
 
       it('[from-1] not in range ' .. input, function()
         local lower = vim.deepcopy(range.from)
         lower.major = lower.major - 1
-        assert(not range:matches(lower))
+        assert(not range:has(lower))
       end)
 
-      it('[to] not in range ' .. input .. ' to:' .. tostring(range and range.to), function()
+      it('[to] not in range ' .. input .. ' to:' .. tostring(range.to), function()
         if range.to then
           assert(not (range.to < range.to))
-          assert(not range:matches(range.to))
+          assert(not range:has(range.to))
         end
       end)
     end
 
-    it("handles prerelease", function()
-      assert(not Semver.range('1.2.3'):matches('1.2.3-alpha'))
-      assert(Semver.range('1.2.3-alpha'):matches('1.2.3-alpha'))
-      assert(not Semver.range('1.2.3-alpha'):matches('1.2.3-beta'))
-    end)
-  end)
-
-  describe('lazy semver order', function()
-    it('is correct', function()
-      assert(v('v1.2.3') == v('1.2.3'))
-      assert(not (v('v1.2.3') < v('1.2.3')))
-      assert(v('v1.2.3') > v('1.2.3-prerelease'))
-      assert(v('v1.2.3-alpha') < v('1.2.3-beta'))
-      assert(v('v1.2.3-prerelease') < v('1.2.3'))
-      assert(v('v1.2.3') >= v('1.2.3'))
-      assert(v('v1.2.3') >= v('1.0.3'))
-      assert(v('v1.2.3') >= v('1.2.2'))
-      assert(v('v1.2.3') > v('1.2.2'))
-      assert(v('v1.2.3') > v('1.0.3'))
-      eq(version.last({ v('1.2.3'), v('2.0.0') }), v('2.0.0'))
-      eq(version.last({ v('2.0.0'), v('1.2.3') }), v('2.0.0'))
+    it('handles prerelease', function()
+      assert(not vim.version.range('1.2.3'):has('1.2.3-alpha'))
+      assert(vim.version.range('1.2.3-alpha'):has('1.2.3-alpha'))
+      assert(not vim.version.range('1.2.3-alpha'):has('1.2.3-beta'))
     end)
   end)
 
@@ -143,12 +123,11 @@ describe('version', function()
       { v1 = '1.0.0-beta.11',    v2 = '1.0.0-rc.1',       want = -1, },
     }
     for _, tc in ipairs(testcases) do
-      local want = ('v1 %s v2'):format(tc.want == 0 and '==' or (tc.want == 1 and '>' or '<'))
+      local msg = function(s) return ('v1 %s v2'):format(s == 0 and '==' or (s == 1 and '>' or '<')) end
       it(string.format('(v1 = %s, v2 = %s)', tc.v1, tc.v2),
         function()
-          local rv = version.cmp(tc.v1, tc.v2, { strict = true })
-          local got = ('v1 %s v2'):format(rv == 0 and '==' or (rv == 1 and '>' or '<'))
-          ok(tc.want == rv, want, got)
+          local rv = vim.version.cmp(tc.v1, tc.v2, { strict = true })
+          ok(tc.want == rv, msg(tc.want), msg(rv))
         end
       )
     end
@@ -157,47 +136,19 @@ describe('version', function()
   describe('parse()', function()
     describe('strict=true', function()
       local testcases = {
-        {
-          desc = 'Nvim version',
-          version = 'v0.9.0-dev-1233+g210120dde81e',
-          want = { major = 0, minor = 9, patch = 0, prerelease = 'dev-1233', build = 'g210120dde81e', },
-        },
-        {
-          desc = 'no leading v',
-          version = '10.20.123',
-          want = { major = 10, minor = 20, patch = 123, prerelease = nil, build = nil, },
-        },
-        {
-          desc = 'leading v',
-          version = 'v1.2.3',
-          want = { major = 1, minor = 2, patch = 3 },
-        },
-        {
-          desc = 'prerelease',
-          version = '1.2.3-alpha',
-          want = { major = 1, minor = 2, patch = 3, prerelease = 'alpha' },
-        },
-        {
-          desc = 'prerelease and other identifiers',
-          version = '1.2.3-alpha.1',
-          want = { major = 1, minor = 2, patch = 3, prerelease = 'alpha.1' },
-        },
-        {
-          desc = 'build',
-          version = '1.2.3+build.15',
-          want = { major = 1, minor = 2, patch = 3, build = 'build.15' },
-        },
-        {
-          desc = 'prerelease and build',
-          version = '1.2.3-rc1+build.15',
-          want = { major = 1, minor = 2, patch = 3, prerelease = 'rc1', build = 'build.15', },
-        },
+        { desc = 'Nvim version',         version = 'v0.9.0-dev-1233+g210120dde81e', want = { major = 0, minor = 9, patch = 0, prerelease = 'dev-1233', build = 'g210120dde81e', }, },
+        { desc = 'no v',                 version = '10.20.123', want = { major = 10, minor = 20, patch = 123, prerelease = nil, build = nil, }, },
+        { desc = 'with v',               version = 'v1.2.3', want = { major = 1, minor = 2, patch = 3 }, },
+        { desc = 'prerelease',           version = '1.2.3-alpha', want = { major = 1, minor = 2, patch = 3, prerelease = 'alpha' }, },
+        { desc = 'prerelease.x',         version = '1.2.3-alpha.1', want = { major = 1, minor = 2, patch = 3, prerelease = 'alpha.1' }, },
+        { desc = 'build.x',              version = '1.2.3+build.15', want = { major = 1, minor = 2, patch = 3, build = 'build.15' }, },
+        { desc = 'prerelease and build', version = '1.2.3-rc1+build.15', want = { major = 1, minor = 2, patch = 3, prerelease = 'rc1', build = 'build.15', }, },
       }
       for _, tc in ipairs(testcases) do
         it(
           string.format('%q: version = %q', tc.desc, tc.version),
           function()
-            eq(tc.want, version.parse(tc.version))
+            eq(tc.want, vim.version.parse(tc.version))
           end
         )
       end
@@ -211,12 +162,13 @@ describe('version', function()
         { version = '1-1.0',    want = { major = 1, minor = 0, patch = 0, prerelease = '1.0' }, },
         { version = 'v1.2.3  ', want = { major = 1, minor = 2, patch = 3 }, },
         { version = '  v1.2.3', want = { major = 1, minor = 2, patch = 3 }, },
+        { version = 'tmux 3.2a', want = { major = 3, minor = 2, patch = 0, }, },
       }
       for _, tc in ipairs(testcases) do
         it(
           string.format('version = %q', tc.version),
           function()
-            eq(tc.want, version.parse(tc.version, { strict = false }))
+            eq(tc.want, vim.version.parse(tc.version, { strict = false }))
           end
         )
       end
@@ -236,6 +188,8 @@ describe('version', function()
         { version = '1.2.3-%?' },
         { version = '1.2.3+%?' },
         { version = '1.2.3+build.0-rc1' },
+        { version = '3.2a', },
+        { version = 'tmux 3.2a', },
       }
 
       local function quote_empty(s)
@@ -244,7 +198,7 @@ describe('version', function()
 
       for _, tc in ipairs(testcases) do
         it(quote_empty(tc.version), function()
-          eq(nil, version.parse(tc.version, { strict = true }))
+          eq(nil, vim.version.parse(tc.version, { strict = true }))
         end)
       end
     end)
@@ -261,21 +215,42 @@ describe('version', function()
         it(string.format('(%s): %s', tc.desc, tostring(tc.version)), function()
           local expected = string.format(type(tc.version) == 'string'
             and 'invalid version: "%s"' or 'invalid version: %s', tostring(tc.version))
-          matches(expected, pcall_err(version.parse, tc.version, { strict = true }))
+          matches(expected, pcall_err(vim.version.parse, tc.version, { strict = true }))
         end)
       end
     end)
   end)
 
+  it('relational metamethods (== < >)', function()
+    assert(v('v1.2.3') == v('1.2.3'))
+    assert(not (v('v1.2.3') < v('1.2.3')))
+    assert(v('v1.2.3') > v('1.2.3-prerelease'))
+    assert(v('v1.2.3-alpha') < v('1.2.3-beta'))
+    assert(v('v1.2.3-prerelease') < v('1.2.3'))
+    assert(v('v1.2.3') >= v('1.2.3'))
+    assert(v('v1.2.3') >= v('1.0.3'))
+    assert(v('v1.2.3') >= v('1.2.2'))
+    assert(v('v1.2.3') > v('1.2.2'))
+    assert(v('v1.2.3') > v('1.0.3'))
+    eq(vim.version.last({ v('1.2.3'), v('2.0.0') }), v('2.0.0'))
+    eq(vim.version.last({ v('2.0.0'), v('1.2.3') }), v('2.0.0'))
+  end)
+
   it('lt()', function()
-    eq(true, version.lt('1', '2'))
+    eq(true, vim.version.lt('1', '2'))
+    eq(false, vim.version.lt({3}, {0, 7, 4}))
+    eq(false, vim.version.lt({major=3, minor=3, patch=0}, {3, 2, 0}))
   end)
 
   it('gt()', function()
-    eq(true, version.gt('2', '1'))
+    eq(true, vim.version.gt('2', '1'))
+    eq(true, vim.version.gt({3}, {0, 7, 4}))
+    eq(true, vim.version.gt({major=3, minor=3, patch=0}, {3, 2, 0}))
   end)
 
   it('eq()', function()
-    eq(true, version.eq('2', '2'))
+    eq(true, vim.version.eq('2', '2'))
+    eq(true, vim.version.eq({3, 1, 0}, '3.1.0'))
+    eq(true, vim.version.eq({major=3, minor=3, patch=0}, {3, 3, 0}))
   end)
 end)
diff --git a/test/functional/terminal/buffer_spec.lua b/test/functional/terminal/buffer_spec.lua
index 676be151ee..b983ea89d5 100644
--- a/test/functional/terminal/buffer_spec.lua
+++ b/test/functional/terminal/buffer_spec.lua
@@ -202,7 +202,7 @@ describe(':terminal buffer', function()
 
     -- Save the buffer number of the terminal for later testing.
     local tbuf = eval('bufnr("%")')
-    local exitcmd = helpers.is_os('win')
+    local exitcmd = is_os('win')
       and "['cmd', '/c', 'exit']"
       or "['sh', '-c', 'exit']"
     source([[