Add impl_from! macro to shorten up error code

server/src/commands/build.rs

@@ -58,29 +58,12 @@ pub enum BuildError {
     BinaryModelEncodeError(rbx_binary::EncodeError)
 }
 
-impl From<ProjectLoadFuzzyError> for BuildError {
-    fn from(error: ProjectLoadFuzzyError) -> BuildError {
-        BuildError::ProjectLoadError(error)
-    }
-}
-
-impl From<io::Error> for BuildError {
-    fn from(error: io::Error) -> BuildError {
-        BuildError::IoError(error)
-    }
-}
-
-impl From<rbx_xml::EncodeError> for BuildError {
-    fn from(error: rbx_xml::EncodeError) -> BuildError {
-        BuildError::XmlModelEncodeError(error)
-    }
-}
-
-impl From<rbx_binary::EncodeError> for BuildError {
-    fn from(error: rbx_binary::EncodeError) -> BuildError {
-        BuildError::BinaryModelEncodeError(error)
-    }
-}
+impl_from!(BuildError {
+    ProjectLoadFuzzyError => ProjectLoadError,
+    io::Error => IoError,
+    rbx_xml::EncodeError => XmlModelEncodeError,
+    rbx_binary::EncodeError => BinaryModelEncodeError
+});
 
 pub fn build(options: &BuildOptions) -> Result<(), BuildError> {
     let output_kind = options.output_kind

server/src/commands/init.rs

@@ -15,11 +15,9 @@ pub enum InitError {
     ProjectInitError(#[fail(cause)] ProjectInitError)
 }
 
-impl From<ProjectInitError> for InitError {
-    fn from(error: ProjectInitError) -> InitError {
-        InitError::ProjectInitError(error)
-    }
-}
+impl_from!(InitError {
+    ProjectInitError => ProjectInitError,
+});
 
 #[derive(Debug)]
 pub struct InitOptions<'a> {

server/src/commands/serve.rs

@@ -26,11 +26,9 @@ pub enum ServeError {
    ProjectLoadError(#[fail(cause)] ProjectLoadFuzzyError),
 }
 
-impl From<ProjectLoadFuzzyError> for ServeError {
-    fn from(error: ProjectLoadFuzzyError) -> ServeError {
-        ServeError::ProjectLoadError(error)
-    }
-}
+impl_from!(ServeError {
+    ProjectLoadFuzzyError => ProjectLoadError,
+});
 
 pub fn serve(options: &ServeOptions) -> Result<(), ServeError> {
     info!("Looking for project at {}", options.fuzzy_project_path.display());

server/src/commands/upload.rs

@@ -35,29 +35,12 @@ pub enum UploadError {
     XmlModelEncodeError(rbx_xml::EncodeError),
 }
 
-impl From<ProjectLoadFuzzyError> for UploadError {
-    fn from(error: ProjectLoadFuzzyError) -> UploadError {
-        UploadError::ProjectLoadError(error)
-    }
-}
-
-impl From<io::Error> for UploadError {
-    fn from(error: io::Error) -> UploadError {
-        UploadError::IoError(error)
-    }
-}
-
-impl From<reqwest::Error> for UploadError {
-    fn from(error: reqwest::Error) -> UploadError {
-        UploadError::HttpError(error)
-    }
-}
-
-impl From<rbx_xml::EncodeError> for UploadError {
-    fn from(error: rbx_xml::EncodeError) -> UploadError {
-        UploadError::XmlModelEncodeError(error)
-    }
-}
+impl_from!(UploadError {
+    ProjectLoadFuzzyError => ProjectLoadError,
+    io::Error => IoError,
+    reqwest::Error => HttpError,
+    rbx_xml::EncodeError => XmlModelEncodeError,
+});
 
 #[derive(Debug)]
 pub struct UploadOptions<'a> {

server/src/impl_from.rs

@@ -0,0 +1,18 @@
+/// Implements 'From' for a list of variants, intended for use with error enums
+/// that are wrapping a number of errors from other methods.
+#[macro_export]
+macro_rules! impl_from {
+    (
+        $enum_name: ident {
+            $($error_type: ty => $variant_name: ident),* $(,)*
+        }
+    ) => {
+        $(
+            impl From<$error_type> for $enum_name {
+                fn from(error: $error_type) -> $enum_name {
+                    $enum_name::$variant_name(error)
+                }
+            }
+        )*
+    }
+}

server/src/lib.rs

@@ -1,3 +1,8 @@
+// Macros
+#[macro_use]
+pub mod impl_from;
+
+// Other modules
 pub mod commands;
 pub mod fs_watcher;
 pub mod imfs;