Remove thiserror (extracted from #64) (#70)

Remove the thiserror crate and replace with the same code that would be
generated.

This change was authored by @overcat in #64, and has been extracted to commit
separately.

Co-authored-by: Jun Luo <[email protected]>

Cargo.toml

@@ -8,7 +8,7 @@ license = "Apache-2.0"
 readme = "README.md"
 version = "0.0.10"
 edition = "2021"
-rust-version = "1.67.0"
+rust-version = "1.81.0"
 
 [features]
 default = []
@@ -28,5 +28,4 @@ proptest = "1.0.0"
 
 [dependencies]
 data-encoding = "2.6.0"
-thiserror = "1.0.36"
 clap = { version = "4.2.4", default-features = false, features = ["std", "derive", "usage", "help"], optional = true }

src/bin/stellar-strkey/decode.rs

@@ -3,12 +3,21 @@ use std::str::FromStr;
 use clap::Args;
 use stellar_strkey::DecodeError;
 
-#[derive(thiserror::Error, Debug)]
+#[derive(Debug)]
 pub enum Error {
-    #[error("decoding {0:?}: {1}")]
     Decode(String, DecodeError),
 }
 
+impl core::fmt::Display for Error {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        match self {
+            Error::Decode(s, inner) => f.write_fmt(format_args!("decoding {s:?}: {inner}")),
+        }
+    }
+}
+
+impl core::error::Error for Error {}
+
 #[derive(Args, Debug, Clone)]
 #[command()]
 pub struct Cmd {

src/error.rs

@@ -1,6 +1,15 @@
-#[derive(thiserror::Error, Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
 pub enum DecodeError {
     // TODO: Add meaningful errors for each problem that can occur.
-    #[error("the strkey is invalid")]
     Invalid,
 }
+
+impl core::fmt::Display for DecodeError {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        match self {
+            DecodeError::Invalid {} => f.write_str("the strkey is invalid"),
+        }
+    }
+}
+
+impl core::error::Error for DecodeError {}