Split env module into multiple files

src/env/parse.rs

@@ -0,0 +1,56 @@
+//! Functions for the `#[config(parse_env = ...)]` attribute.
+
+use std::str::FromStr;
+
+/// Splits the environment variable by separator `SEP`, parses each element
+/// with [`FromStr`] and collects everything via [`FromIterator`].
+///
+/// To avoid having to specify the separator via `::<>` syntax, see the
+/// other functions in this module.
+///
+/// [`FromStr`]: std::str::FromStr
+/// [`FromIterator`]: std::iter::FromIterator
+///
+///
+/// # Example
+///
+/// ```
+/// use confique::Config;
+///
+/// #[derive(Debug, confique::Config)]
+/// struct Conf {
+///     #[config(env = "PORTS", parse_env = confique::env::parse::list_by_sep::<',', _, _>)]
+///     ports: Vec<u16>,
+/// }
+///
+/// std::env::set_var("PORTS", "8080,8000,8888");
+/// let conf = Conf::builder().env().load()?;
+/// assert_eq!(conf.ports, vec![8080, 8000, 8888]);
+/// # Ok::<_, confique::Error>(())
+/// ```
+pub fn list_by_sep<const SEP: char, T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
+where
+    T: FromStr,
+    C: FromIterator<T>,
+{
+    input.split(SEP).map(T::from_str).collect()
+}
+
+
+macro_rules! specify_fn_wrapper {
+    ($fn_name:ident, $sep:literal) => {
+        #[doc = concat!("Like [`list_by_sep`] with `", $sep, "` separator.")]
+        pub fn $fn_name<T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
+        where
+            T: FromStr,
+            C: FromIterator<T>,
+        {
+            list_by_sep::<$sep, _, _>(input)
+        }
+    }
+}
+
+specify_fn_wrapper!(list_by_comma, ',');
+specify_fn_wrapper!(list_by_semicolon, ';');
+specify_fn_wrapper!(list_by_colon, ':');
+specify_fn_wrapper!(list_by_space, ' ');