added last result variable '$'

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "quickmath"
-version = "0.2.3"
+version = "0.2.4"
 edition = "2021"
 authors = [ "Valerie Wolfe <sleeplessval@gmail.com>" ]
 description = "A quick command-line math evaluator."

src/main.rs

@@ -10,9 +10,8 @@ use std::{
 
 use evalexpr::{
 	context_map,
-
 	eval_with_context_mut,
-
+	ContextWithMutableVariables,
 	HashMapContext,
 	Value
 };
@@ -89,37 +88,42 @@ fn main() {
 
 fn do_eval(i_expression: String, context: &mut HashMapContext) {
 	let expression = i_expression.as_str();
-	let i_result = eval_with_context_mut(expression, context);
-	if i_result.is_err() {
+	let result = eval_with_context_mut(expression, context);
+	if let Ok(result) = result {
+		//	display empty result
+		if result.is_empty() {
+			println!(
+				"{green}✓ {bold}{expression}",
+				bold = style::Bold,
+				green = color::Fg(color::Green)
+			);
+			return;
+		}
+
+		//	get appropriate symbol for result by type
+		let delimiter;
+		match result {
+			Value::Boolean(_bool)		=>	delimiter = "is",
+			Value::String(ref _str)		=>	delimiter = "=>",
+			_							=>	delimiter = "="
+		}
+		println!(
+			"{faint}{italic}{expression}{reset} {delimiter} {bold}{result}",
+			bold = style::Bold,
+			faint = style::Faint,
+			italic = style::Italic,
+			reset = style::Reset
+		);
+
+		//	set "last" variable
+		context.set_value("$".to_string(), result).ok();
+	} else {
 		println!(
 			"{red}✕ {bold}{expression}",
 			bold = style::Bold,
 			red = color::Fg(color::Red)
 		);
-		return;
 	}
-	let result = i_result.ok().unwrap();
-	if result.is_empty() {
-		println!(
-			"{green}✓ {bold}{expression}",
-			bold = style::Bold,
-			green = color::Fg(color::Green)
-		);
-		return;
-	}
-	let delimiter;
-	match result {
-		Value::Boolean(_bool)		=>	delimiter = "is",
-		Value::String(ref _str)		=>	delimiter = "=>",
-		_							=>	delimiter = "="
-	}
-	println!(
-		"{faint}{italic}{expression}{reset} {delimiter} {bold}{result}",
-		bold = style::Bold,
-		faint = style::Faint,
-		italic = style::Italic,
-		reset = style::Reset
-	);
 }
 
 fn reset() {