Merge pull request #24 from icetemple/env-type-doc

Add documentation for env string

README.md

@@ -128,7 +128,6 @@ cargo test --all-features
 
 * **default** - ["primitives"]
 * **macro** - Activates `config!` macros for easy configure web application.
-* **array** - Add EnvString impl for vector type (uses optional `serde_json` package).
 * **primitives** - Group for features: `numbers` and `bool`.
 * **numbers** - Group for features: `int`, `uint` and `float`.
 * **int** - Group for features: `i8`, `i16`, `i32`, `i64`, `i128` and `isize`.
@@ -149,6 +148,7 @@ cargo test --all-features
 * **f32** - impl EnvString for `f32` type
 * **f64** - impl EnvString for `f64` type
 * **bool** - impl EnvString for `bool` type
+* **json_array** - Add EnvString impl for vector type (uses optional `serde_json` package). ⚠ **_DEPRECATED_**
 
 
 ## License

itconfig/Cargo.toml

@@ -26,8 +26,6 @@ default = ["primitives"]
 
 macro = ["itconfig-macro"]
 
-array = ["serde_json"]
-
 primitives = ["numbers", "bool"]
 numbers = ["int", "uint", "float"]
 int = ["i8", "i16", "i32", "i64", "i128", "isize"]
@@ -53,6 +51,9 @@ f64   = []
 
 bool  = []
 
+# deprecated since 1.1
+json_array = ["serde_json"]
+
 
 [badges]
 travis-ci = { repository = "icetemple/itconfig-rs" }

itconfig/src/envstr.rs

@@ -1,20 +1,71 @@
 use std::ops::Deref;
 
-#[doc(hidden)]
+/// Wrapper under String type.
+///
+/// When we read the environment variable, we automatically convert the value
+/// to EnvString and then convert it to your expected type.
+///
+#[derive(Debug, PartialEq, Clone)]
+pub struct EnvString(String);
+
+impl<T> From<T> for EnvString
+where
+    T: ToEnvString,
+{
+    fn from(val: T) -> Self {
+        val.to_env_string()
+    }
+}
+
+impl Deref for EnvString {
+    type Target = String;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+/// A trait for converting value to EnvString.
+///
+/// This trait automatically implemented for any type which implements the
+/// [`Display`] trait. As such, `ToEnvString` shouldn't be implemented directly:
+/// [`Display`] should be implemented instead, and you get the `ToEnvString`
+/// implementation for free.
+///
+/// [`Display`]: std::fmt::Display
 pub trait ToEnvString {
+    /// Converts the giving value to a `EnvString`.
+    ///
+    /// # Examples
+    ///
+    /// basic usage
+    ///
+    /// ```rust
+    /// # use itconfig::{EnvString, ToEnvString};
+    /// let i = 5;
+    /// let five = EnvString::from("5");
+    /// assert_eq!(five, i.to_env_string());
+    /// ```
     fn to_env_string(&self) -> EnvString;
 }
 
-#[doc(hidden)]
+/// Simple and safe type conversions that may fail in a controlled way under
+/// some circumstances.
+///
+/// This trait automatically implemented for all standard primitives. If you
+/// want to use your custom type in the library you need to implement
+/// `ToEnvString` and `FromEnvString` manually.
 pub trait FromEnvString: Sized {
+    /// The type returned in the event of a conversion error.
     type Err;
 
+    /// Performs the conversion.
     fn from_env_string(s: &EnvString) -> Result<Self, Self::Err>;
 }
 
 impl<T> ToEnvString for T
 where
-    T: ToString,
+    T: std::fmt::Display,
 {
     #[inline]
     fn to_env_string(&self) -> EnvString {
@@ -68,37 +119,6 @@ impl FromEnvString for bool {
     }
 }
 
-#[cfg(feature = "array")]
-#[derive(Debug)]
-pub enum ArrayEnvError {
-    InvalidType,
-    FailedToParse,
-}
-
-#[cfg(feature = "array")]
-impl<T> FromEnvString for Vec<T>
-where
-    T: FromEnvString,
-{
-    type Err = ArrayEnvError;
-
-    fn from_env_string(s: &EnvString) -> Result<Self, Self::Err> {
-        serde_json::from_str::<Vec<isize>>(s.trim())
-            .map(|vec| vec.iter().map(|v| v.to_string()).collect::<Vec<String>>())
-            .or_else(|_| serde_json::from_str::<Vec<String>>(s.trim()))
-            .map_err(|_| ArrayEnvError::InvalidType)
-            .and_then(|vec| {
-                vec.iter()
-                    .map(|v| {
-                        v.to_env_string()
-                            .parse::<T>()
-                            .map_err(|_| ArrayEnvError::FailedToParse)
-                    })
-                    .collect::<Result<Vec<T>, _>>()
-            })
-    }
-}
-
 impl FromEnvString for String {
     type Err = ();
 
@@ -115,20 +135,42 @@ impl FromEnvString for &'static str {
     }
 }
 
-#[doc(hidden)]
+//===========================================================================//
-#[derive(Debug, PartialEq, Clone)]
+// DEPRECATED                                                                //
-pub struct EnvString(String);
+//===========================================================================//
 
-impl EnvString {
+/// Error type for json array implementation
-    pub fn parse<T: FromEnvString>(&self) -> Result<T, T::Err> {
+#[cfg(feature = "json_array")]
-        FromEnvString::from_env_string(self)
+#[derive(Debug)]
-    }
+#[deprecated(since = "1.1.0")]
+pub enum ArrayEnvError {
+    /// Invalid type.
+    InvalidType,
+
+    /// Failed to parse environment variable
+    FailedToParse,
 }
 
-impl Deref for EnvString {
+#[cfg(feature = "json_array")]
-    type Target = String;
+#[allow(deprecated)]
+impl<T> FromEnvString for Vec<T>
+where
+    T: FromEnvString,
+{
+    type Err = ArrayEnvError;
 
-    fn deref(&self) -> &Self::Target {
+    fn from_env_string(s: &EnvString) -> Result<Self, Self::Err> {
-        &self.0
+        serde_json::from_str::<Vec<isize>>(s.trim())
+            .map(|vec| vec.iter().map(|v| v.to_string()).collect::<Vec<String>>())
+            .or_else(|_| serde_json::from_str::<Vec<String>>(s.trim()))
+            .map_err(|_| ArrayEnvError::InvalidType)
+            .and_then(|vec| {
+                vec.iter()
+                    .map(|v| {
+                        FromEnvString::from_env_string(&v.to_env_string())
+                            .map_err(|_| ArrayEnvError::FailedToParse)
+                    })
+                    .collect::<Result<Vec<T>, _>>()
+            })
     }
 }

itconfig/src/error.rs

@@ -1,9 +1,13 @@
 use std::error;
 use std::fmt;
 
+/// The error type for operations interacting with environment variables
 #[derive(Debug, PartialEq)]
 pub enum EnvError {
+    /// The specified environment variable was not present in the current process's environment.
     MissingVariable(String),
+
+    /// Failed to parse the specified environment variable.
     FailedToParse(String),
 }
 

itconfig/src/getenv.rs

@@ -1,4 +1,5 @@
-use crate::prelude::*;
+use crate::envstr::*;
+use crate::error::*;
 use std::env;
 
 /// Same as get_env but returns Option enum instead Result
@@ -151,17 +152,14 @@ where
         .and_then(|env_str| parse_env_variable(env_name, env_str))
 }
 
-#[doc(hidden)]
 fn parse_env_variable<T>(env_name: &str, env_str: EnvString) -> Result<T, EnvError>
 where
     T: FromEnvString,
 {
-    env_str
+    FromEnvString::from_env_string(&env_str)
-        .parse::<T>()
         .map_err(|_| EnvError::FailedToParse(env_name.to_string()))
 }
 
-#[doc(hidden)]
 fn make_panic<T>(e: EnvError) -> T {
     panic!("{}", e)
 }

itconfig/src/lib.rs

@@ -113,7 +113,6 @@
 //!
 //! * **default** - ["primitives"]
 //! * **macro** - Activates `config!` macros for easy configure web application.
-//! * **array** - Add EnvString impl for vector type (uses optional `serde_json` package).
 //! * **primitives** - Group for features: `numbers` and `bool`.
 //! * **numbers** - Group for features: `int`, `uint` and `float`.
 //! * **int** - Group for features: `i8`, `i16`, `i32`, `i64`, `i128` and `isize`.
@@ -134,12 +133,14 @@
 //! * **f32** - impl EnvString for `f32` type
 //! * **f64** - impl EnvString for `f64` type
 //! * **bool** - impl EnvString for `bool` type
+//! * **json_array** - Add EnvString impl for vector type (uses optional `serde_json` package). ⚠ **_DEPRECATED_**
 //!
 
 // Rustc lints.
 #![forbid(unsafe_code)]
 #![deny(
     missing_debug_implementations,
+    missing_docs,
     unstable_features,
     unused_imports,
     unused_qualifications
@@ -149,18 +150,14 @@
 
 /////////////////////////////////////////////////////////////////////////////
 
-pub mod envstr;
+mod envstr;
 mod error;
 mod getenv;
 
+pub use self::envstr::*;
 pub use self::error::*;
 pub use self::getenv::*;
 
-pub mod prelude {
-    pub use crate::envstr::*;
-    pub use crate::error::*;
-}
-
 #[cfg(feature = "macro")]
 extern crate itconfig_macro;
 #[cfg(feature = "macro")]