Patch to version 0.4.0 (#257)

* uncomment test

* Add random test for logistic regression

* linting

* Bump version

* Add test for logistic regression

* linting

* initial commit

* final

* final-clean

* Bump to 0.4.0

* Fix linter

* cleanup

* Update CHANDELOG with breaking changes

* Update CHANDELOG date

* Add functional methods to DenseMatrix implementation

* linting

* add type declaration in test

* Fix Wasm tests failing

* linting

* fix tests

* linting

* Add type annotations on BBDTree constructor

* fix clippy

* fix clippy

* fix tests

* bump version

* run fmt. fix changelog

---------

Co-authored-by: Edmund Cape <edmund@Edmunds-MacBook-Pro.local>

src/error/mod.rs

@@ -32,6 +32,8 @@ pub enum FailedError {
     SolutionFailed,
     /// Error in input parameters
     ParametersError,
+    /// Invalid state error (should never happen)
+    InvalidStateError,
 }
 
 impl Failed {
@@ -64,6 +66,22 @@ impl Failed {
         }
     }
 
+    /// new instance of `FailedError::ParametersError`
+    pub fn input(msg: &str) -> Self {
+        Failed {
+            err: FailedError::ParametersError,
+            msg: msg.to_string(),
+        }
+    }
+
+    /// new instance of `FailedError::InvalidStateError`
+    pub fn invalid_state(msg: &str) -> Self {
+        Failed {
+            err: FailedError::InvalidStateError,
+            msg: msg.to_string(),
+        }
+    }
+
     /// new instance of `err`
     pub fn because(err: FailedError, msg: &str) -> Self {
         Failed {
@@ -97,6 +115,7 @@ impl fmt::Display for FailedError {
             FailedError::DecompositionFailed => "Decomposition failed",
             FailedError::SolutionFailed => "Can't find solution",
             FailedError::ParametersError => "Error in input, check parameters",
+            FailedError::InvalidStateError => "Invalid state, this should never happen", // useful in development phase of lib
         };
         write!(f, "{failed_err_str}")
     }