Implement xplr.util.version

Closes: https://github.com/sayanarijit/xplr/issues/540

docs/en/src/upgrade-guide.md

@@ -32,13 +32,13 @@ Knowing that we use the `{major}.{minor}.{patch}` versioning format,
 
 e.g.
 
-- `1.0.0` -> `1.0.x`: Bug fix (fully compatible).
+- `1.0.0` -> `1.0.x`: Patch (fully compatible).
 - `1.0.0` -> `1.x.x`: Only backwards compatible. You can't generally use for
   e.g. `app-1.0.0` with `config-1.1.0`. But vice versa is fine.
 - `1.0.0` -> `x.x.x`: Not compatible at all.
 
 Note that until we're `v1`, we'll be using the `{minor}` version number as
-`{major}`, and the `{patch}` fix number as `{minor}` to determine
+`{major}`, and the `{patch}` number as `{minor}` to determine
 compatibility.
 
 </details>

docs/en/src/xplr.util.md

@@ -1,3 +1,16 @@
+### xplr.util.version
+
+Get the current xplr version details.
+
+Type: function() -> { major: number, minor: number, patch: number }
+
+Example:
+
+```lua
+xplr.util.version()
+-- { major = 0, minor = 0, patch = 0 }
+```
+
 ### xplr.util.dirname
 
 Get the directory name of a given path.

src/lua/mod.rs

@@ -29,15 +29,15 @@ fn parse_version(version: &str) -> Result<(u16, u16, u16, Option<u16>)> {
 
     let major = configv.next().unwrap_or_default().parse::<u16>()?;
     let minor = configv.next().unwrap_or_default().parse::<u16>()?;
-    let bugfix = configv
+    let patch = configv
         .next()
         .and_then(|s| s.split('-').next())
         .unwrap_or_default()
         .parse::<u16>()?;
 
-    let beta = configv.next().unwrap_or_default().parse::<u16>().ok();
+    let pre = configv.next().unwrap_or_default().parse::<u16>().ok();
 
-    Ok((major, minor, bugfix, beta))
+    Ok((major, minor, patch, pre))
 }
 
 /// Check the config version and notify users.

src/lua/util.rs

@@ -1,3 +1,4 @@
+use crate::app::VERSION;
 use crate::explorer;
 use crate::lua;
 use crate::msg::in_::external::ExplorerConfig;
@@ -18,6 +19,7 @@ use std::process::Command;
 pub(crate) fn create_table(lua: &Lua) -> Result<Table> {
     let mut util = lua.create_table()?;
 
+    util = version(util, lua)?;
     util = dirname(util, lua)?;
     util = basename(util, lua)?;
     util = absolute(util, lua)?;
@@ -32,6 +34,42 @@ pub(crate) fn create_table(lua: &Lua) -> Result<Table> {
     Ok(util)
 }
 
+/// Get the xplr version details.
+///
+/// Type: function() -> { major: number, minor: number, patch: number }
+///
+/// Example:
+///
+/// ```lua
+/// xplr.util.version()
+/// -- { major = 0, minor = 0, patch = 0 }
+/// ```
+pub fn version<'a>(util: Table<'a>, lua: &Lua) -> Result<Table<'a>> {
+    #[derive(Debug, Default, Serialize, Deserialize)]
+    struct Version {
+        major: u16,
+        minor: u16,
+        patch: u16,
+    }
+
+    let func = lua.create_function(|lua, ()| {
+        let (major, minor, patch, _) =
+            lua::parse_version(VERSION).map_err(LuaError::custom)?;
+
+        let version = Version {
+            major,
+            minor,
+            patch,
+        };
+
+        let res = lua::serialize(lua, &version).map_err(LuaError::custom)?;
+        Ok(res)
+    })?;
+
+    util.set("version", func)?;
+    Ok(util)
+}
+
 /// Get the directory name of a given path.
 ///
 /// Type: function( path:string ) -> path:string|nil
@@ -215,8 +253,8 @@ pub fn from_json<'a>(util: Table<'a>, lua: &Lua) -> Result<Table<'a>> {
 /// -- }]]
 /// ```
 pub fn to_json<'a>(util: Table<'a>, lua: &Lua) -> Result<Table<'a>> {
-    #[derive(Debug, Default, Serialize, Deserialize, Clone, PartialEq, Eq)]
-    pub struct Options {
+    #[derive(Debug, Default, Serialize, Deserialize)]
+    struct Options {
         pretty: bool,
     }