added rustyline

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "quickmath"
-version = "0.2.3"
+version = "0.3.0"
 edition = "2021"
 authors = [ "Valerie Wolfe <sleeplessval@gmail.com>" ]
 description = "A quick command-line math evaluator."
@@ -14,6 +14,7 @@ path = "src/main.rs"
 
 [dependencies]
 evalexpr = "11.0.0"
+rustyline = "14.0.0"
 termion = "1.5.6"
 
 [profile.release]

src/helper.rs

@@ -15,7 +15,7 @@ pub fn fix(arg: &Value) -> EvalResult {
 
 	let count = args.len();
 	if count != 2 {
-		return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2, actual: count });
+		return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2..=2, actual: count });
 	}
 
 	let float = args[0].as_float()?;
@@ -63,7 +63,7 @@ pub fn logarithm(arg: &Value) -> EvalResult {
 			output = value.log(base).into();
 		},
 		_ => {
-			return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2, actual: count });
+			return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2..=2, actual: count });
 		}
 	}
 	return Ok(output);

src/main.rs

@@ -1,7 +1,6 @@
 use std::{
 	env,
 	io::{
-		stdin,
 		stdout,
 
 		Write
@@ -16,6 +15,7 @@ use evalexpr::{
 	HashMapContext,
 	Value
 };
+use rustyline::DefaultEditor;
 use termion::{
 	color,
 	style
@@ -62,33 +62,27 @@ fn main() {
 		for expression in expressions {
 			match expression.as_str() {
 				"help"	=>	help_text(),
-				_		=>	do_eval(expression, &mut context)
+				_		=>	do_eval(&expression, &mut context)
 			}
 		}
 	} else {
+		let mut rl = DefaultEditor::new().unwrap();
 		//	enter interactive mode if no args are given
 		println!("{}quickmaths v{}{}\n{}Interactive Mode{}", style::Bold, VERSION, style::Reset, style::Faint, style::Reset);
 		loop {
-			print!("> ");
-			stdout().flush().unwrap();
-			let mut i_line = String::new();
-			let line_result = stdin().read_line(&mut i_line);
-			if line_result.is_err() {
-				break;
-			}
-			let line = i_line.trim().to_string();
-			match line.as_str() {
-				""		|
-				"exit"	=>	break,
-				_		=>	do_eval(line, &mut context)
+			match rl.readline("> ").as_deref() {
+				Ok("")		|
+				Ok("exit")	|
+				Err(_)		=>	break,
+
+				Ok(line)	=>	do_eval(line, &mut context),
 			}
 			reset();
 		}
 	}
 }
 
-fn do_eval(i_expression: String, context: &mut HashMapContext) {
-	let expression = i_expression.as_str();
+fn do_eval(expression: &str, context: &mut HashMapContext) {
 	let i_result = eval_with_context_mut(expression, context);
 	if i_result.is_err() {
 		println!(