Add a FromStr impl to the xed_enum! macro

src/error.rs

@@ -83,17 +83,17 @@ impl std::error::Error for Error {}
 
 /// Error for when converting an integer to an enum fails.
 #[derive(Copy, Clone, Debug)]
-pub struct InvalidEnumValue {
-    value: u32,
+pub struct InvalidEnumValue<T = u32> {
+    value: T,
     name: &'static str,
 }
 
-impl InvalidEnumValue {
-    pub(crate) fn new(value: u32, name: &'static str) -> Self {
+impl<T> InvalidEnumValue<T> {
+    pub(crate) fn new(value: T, name: &'static str) -> Self {
         Self { value, name }
     }
 
-    pub fn value(self) -> u32 {
+    pub fn value(self) -> T {
         self.value
     }
 
@@ -102,13 +102,13 @@ impl InvalidEnumValue {
     }
 }
 
-impl fmt::Display for InvalidEnumValue {
+impl<T: fmt::Debug> fmt::Display for InvalidEnumValue<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?} is not a valid value for {}", self.value, self.name)
     }
 }
 
-impl std::error::Error for InvalidEnumValue {}
+impl<T: fmt::Debug> std::error::Error for InvalidEnumValue<T> {}
 
 // #[derive(Copy, Clone, Debug)]
 // pub struct DisassembleError(());

src/macros/xed_enum.rs

@@ -99,6 +99,39 @@ macro_rules! xed_enum {
             }
         }
 
+        impl std::str::FromStr for $name {
+            type Err = crate::InvalidEnumValue<String>;
+
+            fn from_str(s: &str) -> Result<Self, Self::Err> {
+                let mut owned = String::with_capacity(s.len() + 1);
+                owned.push_str(s);
+                owned.push('\0');
+
+                let cstr = match std::ffi::CStr::from_bytes_with_nul(owned.as_bytes()) {
+                    Ok(cstr) => cstr,
+                    Err(_) => {
+                        owned.pop();
+                        return Err(crate::InvalidEnumValue::new(owned, stringify!($name)));
+                    }
+                };
+
+                let variant = unsafe {
+                    paste::paste!($crate::macros::first!(
+                        $( [ xed_sys::[< str2 $enum_name >](cstr.as_ptr()) ] )?
+                        [ xed_sys::[< str2 $base:lower _enum_t >](cstr.as_ptr()) ]
+                    ))
+                };
+
+                match Self::from_raw(variant) {
+                    Some(value) => Ok(value),
+                    None => {
+                        owned.pop();
+                        Err(crate::InvalidEnumValue::new(owned, stringify!($name)))
+                    }
+                }
+            }
+        }
+
         paste::paste! {
             #[test]
             fn [< $name:snake:lower _up_to_date >]() {