Merge pull request #7 from sile/remove-thiserror

Replace `thiserror` crate with manual error trait implementations

Author: sile

Cargo.toml

@@ -14,7 +14,6 @@ license = "MIT"
 rand = "0.8"
 rand_distr = "0.4"
 statrs = "0.15"
-thiserror = "1"
 
 [dev-dependencies]
 anyhow = "1"

src/lib.rs

@@ -296,21 +296,36 @@ struct Trial {
 }
 
 /// Possible errors during [`TpeOptimizerBuilder::build`].
-#[derive(Debug, Clone, thiserror::Error)]
+#[derive(Debug, Clone)]
 pub enum BuildError {
-    #[error("the value of `gamma` must be in the range from 0.0 to 1.0")]
     /// The value of `gamma` must be in the range from `0.0` to `1.0`.
     GammaOutOfRange,
 
-    #[error("the value of `candidates` must be a positive integer")]
     /// The value of `candidates` must be a positive integer.
     ZeroCandidates,
 }
 
+impl std::fmt::Display for BuildError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            BuildError::GammaOutOfRange => {
+                write!(
+                    f,
+                    "the value of `gamma` must be in the range from 0.0 to 1.0"
+                )
+            }
+            BuildError::ZeroCandidates => {
+                write!(f, "the value of `candidates` must be a positive integer")
+            }
+        }
+    }
+}
+
+impl std::error::Error for BuildError {}
+
 /// Possible errors during [`TpeOptimizer::tell`].
-#[derive(Debug, Clone, thiserror::Error)]
+#[derive(Debug, Clone)]
 pub enum TellError {
-    #[error("the parameter value {param} is out of the range {range}")]
     /// The parameter value is out of the range.
     ParamOutOfRange {
         /// Actual parameter value.
@@ -319,11 +334,29 @@ pub enum TellError {
         range: Range,
     },
 
-    #[error("NaN value is not allowed")]
     /// NaN value is not allowed.
     NanValue,
 }
 
+impl std::fmt::Display for TellError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            TellError::ParamOutOfRange { param, range } => {
+                write!(
+                    f,
+                    "the parameter value {} is out of the range {}",
+                    param, range
+                )
+            }
+            TellError::NanValue => {
+                write!(f, "NaN value is not allowed")
+            }
+        }
+    }
+}
+
+impl std::error::Error for TellError {}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/range.rs

@@ -49,13 +49,22 @@ impl Range {
 }
 
 /// Possible errors during [`Range`] construction.
-#[derive(Debug, Clone, thiserror::Error)]
+#[derive(Debug, Clone)]
 pub enum RangeError {
-    #[error("not a finite range")]
     /// Not a finite range.
     NonFiniteRange,
 
-    #[error("an empty range")]
     /// An empty range.
     EmptyRange,
 }
+
+impl std::fmt::Display for RangeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RangeError::NonFiniteRange => write!(f, "not a finite range"),
+            RangeError::EmptyRange => write!(f, "an empty range"),
+        }
+    }
+}
+
+impl std::error::Error for RangeError {}