From b0602388e7663b22e9472646366982984f723b7b Mon Sep 17 00:00:00 2001
From: emma <emma@tebibyte.media>
Date: Sat, 13 Jul 2024 18:29:27 -0600
Subject: [PATCH] rpn(1): better comments

---
 src/rpn.rs | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/rpn.rs b/src/rpn.rs
index 2bfbbf5..784e323 100644
--- a/src/rpn.rs
+++ b/src/rpn.rs
@@ -57,7 +57,7 @@ extern crate sysexits;
 use sysexits::EX_DATAERR;
 
 #[derive(Clone, PartialEq, PartialOrd, Debug)]
-// enum CalcType is a type containing operations used in the calculator
+/* enum CalcType is a type containing operations used in the calculator */
 enum CalcType {
 	Add,
 	Subtract,
@@ -117,8 +117,8 @@ struct EvaluationError {
 	code: i32,
 }
 
-// I’m no math nerd but I want the highest possible approximation of 0.9
-// repeating and it seems this can give it to me
+/* I’m no math nerd but I want the highest possible approximation of 0.9
+ * repeating and it seems this can give it to me */
 const PRECISION_MOD: f64 = 0.9 + f64::EPSILON * 100.0;
 
 fn eval(
@@ -133,7 +133,7 @@ fn eval(
 		return Ok((stack, oper));
 	}
 
-	// Split the input into tokens.
+	/* Split the input into tokens. */
 	let mut toks: VecDeque<CalcType> = input
 		.split_whitespace()
 		.rev()
@@ -183,7 +183,7 @@ fn eval(
 	Ok((stack, oper))
 }
 
-// Round a float to the given precision level
+/* Round a float to the given precision level */
 fn round_precise(value: &f64, precision: usize) -> f64 {
 	let multiplier = 10_f64.powi(precision as i32);
 	(value * multiplier).round() / multiplier
@@ -193,11 +193,11 @@ fn main() -> ExitCode {
 	let argv = args().collect::<Vec<String>>();
 	let mut stack = VecDeque::new();
 	let mut buf = String::new();
-	// Set floating-point precision for correcting rounding errors based on
-	// machine epsilon
+	/* Set floating-point precision for correcting rounding errors based on
+	 * machine epsilon */
 	let precision = (-f64::EPSILON.log10() * PRECISION_MOD).ceil() as usize;
 	
-	if argv.get(1).is_none() {
+	if argv.get(1).is_none() { /* read from stdin */
 		while let Ok(_) = stdin().read_line(&mut buf) {
 			match eval(&buf.trim(), stack) {
 				Ok(s) => {
@@ -219,12 +219,13 @@ fn main() -> ExitCode {
 				},
 			};
 		}
-	} else {
+	} else { /* read from argv */
+		/* join argv into an owned String joined by spaces minus argv[0] */
 		let input = argv
 			.iter()
 			.skip(1)
 			.map(|x| x.to_owned())
-			.collect::<Vec<String>>()
+			.collect::<Vec<_>>()
 			.join(" ");
 
 		match eval(&input, stack) {
@@ -233,7 +234,7 @@ fn main() -> ExitCode {
 
 				let val = match stack.iter().last() {
 					Some(v) => v,
-					None => return ExitCode::from(0),
+					None => return ExitCode::SUCCESS,
 				};
 
 				println!("{}", round_precise(val, precision).to_string())
@@ -244,5 +245,5 @@ fn main() -> ExitCode {
 			},
 		};
 	}
-	ExitCode::from(0)
+	ExitCode::SUCCESS
 }