add LidoError

Author: billythedummy

core/src/err.rs

@@ -0,0 +1,20 @@
+use core::{error::Error, fmt::Display};
+
+/// NB: this is not in the order defined by the program
+/// TODO: `seqconsts!()` this to make it so
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum LidoError {
+    CalculationFailure,
+    ExchangeRateNotUpdatedInThisEpoch,
+    InvalidAmount,
+    ValidatorWithMoreStakeExists,
+}
+
+impl Display for LidoError {
+    // Display=Debug, since this is just a simple str enum
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
+impl Error for LidoError {}

core/src/lib.rs

@@ -1,5 +1,6 @@
 #![cfg_attr(not(test), no_std)]
 
+mod err;
 mod instructions;
 mod internal_utils;
 mod keys;
@@ -8,6 +9,7 @@ mod quote;
 mod state;
 mod typedefs;
 
+pub use err::*;
 pub use instructions::*;
 pub use keys::*;
 pub use pda::*;