Merge pull request #7 from chanced/impl-std-error

adds missing `impl std::error::Error`s to `Error`, `NotFoundError`, `MalformedError`

Author: chanced

Cargo.toml

@@ -1,23 +1,22 @@
 [package]
-name = "jsonptr"
-version = "0.3.4"
-edition = "2021"
-description = "Data structures and logic for resolving, assigning, and deleting by JSON Pointers (RFC 6901)"
+authors       = ["chance dinkins"]
+description   = "Data structures and logic for resolving, assigning, and deleting by JSON Pointers (RFC 6901)"
 documentation = "https://docs.rs/jsonptr"
-keywords = ["json-pointer", "rfc-6901", "6901"]
-license = "MIT OR Apache-2.0"
-repository = "https://github.com/chanced/jsonptr"
-homepage = "https://github.com/chanced/jsonptr"
-authors = ["chance dinkins"]
-
+edition       = "2021"
+homepage      = "https://github.com/chanced/jsonptr"
+keywords      = ["json-pointer", "rfc-6901", "6901"]
+license       = "MIT OR Apache-2.0"
+name          = "jsonptr"
+repository    = "https://github.com/chanced/jsonptr"
+version       = "0.3.4"
 
 [dependencies]
-serde_json = { version = "1.0", default-features = false, features = ["alloc"] }
-serde = { version = "1.0", default-features = false, features = ["alloc"] }
-url = { version = "2", optional = true }
-uniresid = { version = "0.1.4", optional = true }
 fluent-uri = { version = "0.1.4", optional = true, default-features = false }
+serde      = { version = "1.0", default-features = false, features = ["alloc"] }
+serde_json = { version = "1.0", default-features = false, features = ["alloc"] }
+uniresid   = { version = "0.1.4", optional = true }
+url        = { version = "2", optional = true }
 
 [features]
 default = []
-std = ["serde/std", "serde_json/std", "fluent-uri?/std"]
+std     = ["serde/std", "serde_json/std", "fluent-uri?/std"]

src/error.rs

@@ -85,6 +85,9 @@ impl Display for Error {
     }
 }
 
+#[cfg(feature = "std")]
+impl std::error::Error for Error {}
+
 /// Represents an error that occurs when attempting to resolve a `Pointer` that
 /// encounters a leaf node (i.e. a scalar / null value) which is not the root
 /// of the `Pointer`.
@@ -106,6 +109,10 @@ pub struct UnresolvableError {
     /// `Object` or an `Array`.
     pub leaf: Option<Token>,
 }
+
+#[cfg(feature = "std")]
+impl std::error::Error for UnresolvableError {}
+
 impl UnresolvableError {
     /// Creates a new `UnresolvableError` with the given `Pointer`.
     pub fn new(pointer: Pointer) -> Self {
@@ -298,6 +305,8 @@ impl Display for NotFoundError {
         )
     }
 }
+#[cfg(feature = "std")]
+impl std::error::Error for NotFoundError {}
 
 /// Returned from `Pointer::replace_token` when the provided index is out of
 /// bounds.
@@ -312,6 +321,7 @@ pub struct ReplaceTokenError {
 }
 #[cfg(feature = "std")]
 impl std::error::Error for ReplaceTokenError {}
+
 impl Display for ReplaceTokenError {
     fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
         write!(