From 60f91bf9151915c2f683217555580b43d8a477c7 Mon Sep 17 00:00:00 2001
From: Dmitriy Pleshevskiy <dmitriy@ideascup.me>
Date: Sun, 29 Dec 2019 10:35:50 +0300
Subject: [PATCH] feat: improve macro

---
 README.md           |  2 +-
 itconfig/Cargo.toml |  2 +-
 itconfig/src/lib.rs | 67 ++++++++++++++-------------------------------
 3 files changed, 22 insertions(+), 49 deletions(-)

diff --git a/README.md b/README.md
index 7c923f3..4f896e0 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # itconfig
 [![Build Status](https://travis-ci.org/icetemple/itconfig-rs.svg?branch=master)](https://travis-ci.org/icetemple/itconfig-rs)
 [![Documentation](https://docs.rs/itconfig/badge.svg)](https://docs.rs/itconfig)
-[![Crates.io](https://img.shields.io/badge/crates.io-v0.5.0-orange.svg?longCache=true)](https://crates.io/crates/itconfig) 
+[![Crates.io](https://img.shields.io/badge/crates.io-v0.5.1-orange.svg?longCache=true)](https://crates.io/crates/itconfig) 
 [![Join the chat at https://gitter.im/icetemple/itconfig-rs](https://badges.gitter.im/icetemple/itconfig-rs.svg)](https://gitter.im/icetemple/itconfig-rs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 Easy build a configs from environment variables and use it in globally.
diff --git a/itconfig/Cargo.toml b/itconfig/Cargo.toml
index 6575af8..4feab02 100644
--- a/itconfig/Cargo.toml
+++ b/itconfig/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "itconfig"
-version = "0.5.0"
+version = "0.5.1"
 authors = ["Dmitriy Pleshevskiy <dmitriy@ideascup.me>"]
 description = "Easy build a configs from environment variables and use it in globally."
 categories = ["config", "web-programming"]
diff --git a/itconfig/src/lib.rs b/itconfig/src/lib.rs
index 0d1d734..2ded831 100644
--- a/itconfig/src/lib.rs
+++ b/itconfig/src/lib.rs
@@ -298,33 +298,11 @@ macro_rules! __itconfig_parse_variables {
         }
     };
 
-    // Find variable with default value
+    // Find variable
     (
         tokens = [
             $(#$meta:tt)*
-            $name:ident : $ty:ty => $default:expr,
-            $($rest:tt)*
-        ],
-        $($args:tt)*
-    ) => {
-        __itconfig_parse_variables! {
-            current_variable = {
-                unparsed_meta = [$(#$meta)*],
-                meta = [],
-                name = $name,
-                ty = $ty,
-                default = $default,
-            },
-            tokens = [$($rest)*],
-            $($args)*
-        }
-    };
-
-    // Find variable without default value
-    (
-        tokens = [
-            $(#$meta:tt)*
-            $name:ident : $ty:ty,
+            $name:ident : $ty:ty$( => $default:expr)?,
             $($rest:tt)*
         ],
         $($args:tt)*
@@ -335,6 +313,7 @@ macro_rules! __itconfig_parse_variables {
                 meta = [],
                 name = $name,
                 ty = $ty,
+                $(default = $default,)?
             },
             tokens = [$($rest)*],
             $($args)*
@@ -534,38 +513,18 @@ macro_rules! __itconfig_variable {
         }
     };
 
-    // Add method without default value
-    (
-        meta = $meta:tt,
-        name = $name:ident,
-        env_prefix = $env_prefix:expr,
-        env_name = $env_name:expr,
-        ty = $ty:ty,
-    ) => {
-        __itconfig_variable! {
-            meta = $meta,
-            name = $name,
-            env_prefix = $env_prefix,
-            env_name = $env_name,
-            ty = $ty,
-            default = panic!(format!(r#"Cannot read "{}" environment variable"#, $env_name)),
-        }
-    };
-
-    // Add method with default value
+    // Add method
     (
         meta = [$(#$meta:tt,)*],
         name = $name:ident,
         env_prefix = $env_prefix:expr,
         env_name = $env_name:expr,
         ty = $ty:ty,
-        default = $default:expr,
+        $(default = $default:expr,)?
     ) => {
         $(#$meta)*
         pub fn $name() -> $ty {
-            env::var($env_name)
-                .map(|val| EnvValue::from(val).into())
-                .unwrap_or_else(|_| $default)
+            env_or!($env_name$(, $default)?)
         }
     };
 
@@ -575,3 +534,17 @@ macro_rules! __itconfig_variable {
     };
 }
 
+
+#[macro_export]
+macro_rules! env_or {
+    ($env_name:expr) => {
+        env_or!($env_name, panic!(format!(r#"Cannot read "{}" environment variable"#, $env_name)));
+    };
+
+    ($env_name:expr, $default:expr) => {
+        env::var($env_name)
+            .map(|val| EnvValue::from(val).into())
+            .unwrap_or_else(|_| $default)
+    };
+}
+