feat: converting error handing to anyhow (#49)

Author: DeveloperC286

Cargo.lock

@@ -19,6 +19,9 @@ pretty_env_logger = "0.5.0"
 # For custom errors.
 thiserror = "1.0.61"
 
+# For error handling.
+anyhow = "1.0.89"
+
 
 [dev-dependencies]
 # For parameterised testing.

Cargo.toml

@@ -3,7 +3,7 @@ use crate::evaluator::model::evaluation_error::EvaluationError;
 use crate::evaluator::model::object::Object;
 use crate::syntax_analysis::model::syntax_tree_node::*;
 
-mod model;
+pub mod model;
 
 mod expression;
 mod statement;

src/evaluator/mod.rs

@@ -1,3 +1,3 @@
 pub(super) mod environment;
 pub(super) mod evaluation_error;
-pub(super) mod object;
+pub mod object;

src/evaluator/model/mod.rs

@@ -2,14 +2,48 @@
 extern crate log;
 extern crate pretty_env_logger;
 
+use std::io::{stdin, stdout, Write};
+
+use anyhow::{Context, Result};
+
+use crate::evaluator::Evaluator;
+use crate::lexical_analysis::LexicalAnalysis;
+use crate::syntax_analysis::SyntaxAnalysis;
+
 mod evaluator;
-mod interpreter;
 mod lexical_analysis;
 mod syntax_analysis;
 
 fn main() {
     pretty_env_logger::init();
-    interpreter::repl();
+    trace!("Version {}.", env!("CARGO_PKG_VERSION"));
+    let mut evaluator = crate::evaluator::Evaluator::new();
+
+    loop {
+        if let Err(error) = repl(&mut evaluator) {
+            error!("{}", error);
+        }
+    }
+}
+fn repl(evaluator: &mut Evaluator) -> Result<()> {
+    print!(" >>> ");
+    let input = read()?;
+    let tokens = LexicalAnalysis::from(&input)?;
+    let abstract_syntax_tree = SyntaxAnalysis::from(tokens)?;
+    let object = evaluator.evaluate(abstract_syntax_tree)?;
+    println!("{:?}", object);
+    Ok(())
+}
+
+fn read() -> Result<String> {
+    let mut buffer = String::new();
+
+    let _ = stdout().flush();
+    stdin()
+        .read_line(&mut buffer)
+        .context("Unable to read user input from standard input.")?;
+
+    Ok(buffer)
 }
 
 #[cfg(test)]