improve comparisons

src/lexer.rs

@@ -12,27 +12,19 @@ use crate::FunctionIdentifier::{Cbrt, Ceil, Cos, Exp, Abs, Floor, Ln, Log, Round
 use crate::units::Unit;
 use crate::units::Unit::*;
 use unicode_segmentation::{Graphemes, UnicodeSegmentation};
+use std::cmp::Ordering;
 
 fn is_word_char_str(input: &str) -> bool {
-  let x = match input {
-    "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L"
+  matches!(input, "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L"
     | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X"
-    | "Y" | "Z" => true,
-    "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l"
+    | "Y" | "Z" | "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l"
     | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x"
-    | "y" | "z" => true,
-    "Ω" | "Ω" | "µ" | "μ" => true,
-    _ => false,
-  };
-  return x;
+    | "y" | "z" | "Ω" | "Ω" | "µ" | "μ")
+
 }
 
 fn is_numeric_str(input: &str) -> bool {
-  match input {
-    "." => true,
-    "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" => true,
-    _ => false,
-  }
+  matches!(input, "." | "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9")
 }
 
 /// Read next characters as a word, otherwise return empty string.
@@ -54,7 +46,7 @@ fn read_word_plain(chars: &mut Peekable<Graphemes>) -> String {
 fn read_word(first_c: &str, lexer: &mut Lexer) -> String {
   let chars = &mut lexer.chars;
   let mut word = first_c.trim().to_owned();
-  if word == "" {
+  if word.is_empty() {
     // skip whitespace
     while let Some(current_char) = chars.peek() {
       if current_char.trim().is_empty() {
@@ -71,7 +63,7 @@ fn read_word(first_c: &str, lexer: &mut Lexer) -> String {
       break;
     }
   }
-  if word != "" {
+  if !word.is_empty() {
     match *chars.peek().unwrap_or(&"") {
       "2" | "²" => {
         word += "2";
@@ -633,15 +625,19 @@ pub fn lex(input: &str, remove_trailing_operator: bool, default_degree: Unit) ->
   }
   let tokens = &mut lexer.tokens;
   // auto insert missing parentheses in first and last position
-  if lexer.left_paren_count > lexer.right_paren_count {
-    let missing_right_parens = lexer.left_paren_count - lexer.right_paren_count;
-    for _ in 0..missing_right_parens {
-      tokens.push(Token::Operator(RightParen));
+  match lexer.left_paren_count.cmp(&lexer.right_paren_count) {
+    Ordering::Less => {
+      let missing_left_parens = lexer.right_paren_count - lexer.left_paren_count;
+      for _ in 0..missing_left_parens {
+        tokens.insert(0, Token::Operator(LeftParen));
+      }
     }
-  } else if lexer.left_paren_count < lexer.right_paren_count {
-    let missing_left_parens = lexer.right_paren_count - lexer.left_paren_count;
-    for _ in 0..missing_left_parens {
-      tokens.insert(0, Token::Operator(LeftParen));
+    Ordering::Equal => {}
+    Ordering::Greater => {
+      let missing_right_parens = lexer.left_paren_count - lexer.right_paren_count;
+      for _ in 0..missing_right_parens {
+        tokens.push(Token::Operator(RightParen));
+      }
     }
   }
 

src/lib.rs

@@ -232,20 +232,20 @@ pub fn eval(input: &str, allow_trailing_operators: bool, default_degree: Unit, v
   match lexer::lex(input, allow_trailing_operators, default_degree) {
     Ok(tokens) => {
       let lex_time = Instant::now().duration_since(lex_start).as_nanos() as f32;
-      if verbose == true { println!("Lexed TokenVector: {:?}", tokens); }
+      if verbose { println!("Lexed TokenVector: {:?}", tokens); }
 
       let parse_start = Instant::now();
       match parser::parse(&tokens) {
         Ok(ast) => {
           let parse_time = Instant::now().duration_since(parse_start).as_nanos() as f32;
-          if verbose == true { println!("Parsed AstNode: {:#?}", ast); }
+          if verbose { println!("Parsed AstNode: {:#?}", ast); }
 
           let eval_start = Instant::now();
           match evaluator::evaluate(&ast) {
             Ok(answer) => {
               let eval_time = Instant::now().duration_since(eval_start).as_nanos() as f32;
 
-              if verbose == true {
+              if verbose {
                 println!("Evaluated value: {} {:?}", answer.value, answer.unit);
                 println!("\u{23f1}  {:.3}ms lexing", lex_time/1000.0/1000.0);
                 println!("\u{23f1}  {:.3}ms parsing", parse_time/1000.0/1000.0);

src/units.rs

@@ -544,15 +544,13 @@ fn actual_multiply(left: Number, right: Number, swapped: bool) -> Result<Number,
     // 1 watt * 1 second = 1 joule
     let result = (left.value * left.unit.weight()) * (right.value * right.unit.weight() / Unit::Second.weight());
     match right.unit {
-      Second => return Ok(to_ideal_joule_unit(Number::new(result, Joule))),
-      _ => return Ok(to_ideal_unit(Number::new(result, Joule))),
-    };
-  } else {
-    if swapped == true {
-      Err(format!("Cannot multiply {:?} and {:?}", right.unit, left.unit))
-    } else {
-      actual_multiply(right, left, true)
+      Second => Ok(to_ideal_joule_unit(Number::new(result, Joule))),
+      _ => Ok(to_ideal_unit(Number::new(result, Joule))),
     }
+  } else if swapped {
+    Err(format!("Cannot multiply {:?} and {:?}", right.unit, left.unit))
+  } else {
+    actual_multiply(right, left, true)
   }
 }