added errors for interaction with environments

Author: stepkun

CHANGELOG.md

@@ -16,20 +16,19 @@ especially the [Rust flavour](https://doc.rust-lang.org/cargo/reference/semver.h
 
 ### Removed
 
-## [0.2.0] - 2025-??-??
+## [0.2.0] - 2025-08-29
 
 ### Added
+- error handling necessary for interacting with `Environment`s
 
 ### Changed
 - contribution modalities
-- separated error handling for trait `Environment`
+- moved `Environment` into own submodule
 
 ### Fixed
 - solved open todo!()'s
 - non static lifetime for enum registration function
 
-### Removed
-
 ## [0.1.4] - 2025-08-11
 
 ### Changed

README.md

@@ -8,7 +8,7 @@ The implementation follows the pattern of `clox` as described in Part III of [cr
 ## Usage
 
 ```rust
-use tinyscript::{Runtime, DefaultEnvironment};
+use tinyscript::{Runtime, environment::DefaultEnvironment};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut runtime = Runtime::default();

src/environment.rs

@@ -53,6 +53,22 @@ pub enum Error {
 		/// Name of the variable
 		name: ConstString,
 	},
+
+	/// An external error when setting the variable.
+	EnvVarSet {
+		/// Name of the variable
+		name: ConstString,
+		/// Cause of error
+		cause: ConstString,
+	},
+
+	/// An error when casting the type of the variable.
+	EnvVarTypeCast {
+		/// Name of the variable
+		name: ConstString,
+		/// Expected type ofthe variable
+		var_type: ConstString,
+	},
 }
 
 impl core::error::Error for Error {
@@ -74,6 +90,8 @@ impl core::fmt::Debug for Error {
 			Self::EnvVarNotDefined { name } => write!(f, "EnvVarNotDefined({name})"),
 			Self::EnvVarUnknownType { name } => write!(f, "EnvVarlUnknownTType({name})"),
 			Self::EnvVarWrongType { name } => write!(f, "EnvVarWrongType({name})"),
+			Self::EnvVarSet { name, cause } => write!(f, "EnvVarSet({name}, {cause})"),
+			Self::EnvVarTypeCast { name, var_type } => write!(f, "EnvVarTypeCast({name}, {var_type})"),
 		}
 	}
 }
@@ -92,6 +110,10 @@ impl core::fmt::Display for Error {
 					"the type of the environment variable {name} does not match its former definition"
 				)
 			}
+			Self::EnvVarSet { name, cause } => {
+				write!(f, "setting environment variable {name} failed: {cause}")
+			}
+			Self::EnvVarTypeCast { name, var_type } => write!(f, "cast of variable {name} to {var_type} failed"),
 		}
 	}
 }

src/lib.rs

@@ -15,7 +15,6 @@ pub mod execution;
 pub mod runtime;
 
 // flatten
-pub use environment::{DefaultEnvironment, Environment};
 pub use error::Error;
 pub use execution::Chunk;
 pub use runtime::{Runtime, SharedRuntime};