code and user experience improvements

src/lib.rs

@@ -30,7 +30,7 @@ pub struct ChartManager {
     min_y: f32,
     max_y: f32,
     num_interval: usize,
-    resolution: i32,
+    resolution: usize,
     back_cache: Cache<Vec<(f32, f32)>>,
     front_cache: Cache<(Vec<(f32, f32, f32)>, f32)>,
 }
@@ -39,7 +39,7 @@ pub struct ChartManager {
 impl ChartManager {
     pub fn new(
         func_str: String, min_x: f32, max_x: f32, min_y: f32, max_y: f32, num_interval: usize,
-        resolution: i32,
+        resolution: usize,
     ) -> Self {
         Self {
             func_str,
@@ -63,6 +63,7 @@ impl ChartManager {
         func
     }
 
+    // Tests function to make sure it's able to be parsed. Returns the string of the Error produced, or an empty string if it runs successfully.
     pub fn test_func(function_string: String) -> String {
         let new_func_str: String = add_asterisks(function_string.clone());
         let expr_result = new_func_str.parse();
@@ -87,13 +88,6 @@ impl ChartManager {
         "".to_string()
     }
 
-    // Recommends a possible solution to an error from method `test_func`
-    pub fn error_recommend(error_string: String) -> String {
-        match error_string.as_str() {
-            _ => "Make sure you're using proper syntax! Check the 'Frequent issues' for possible fixes."
-        }.to_string()
-    }
-
     #[inline]
     fn draw(
         &mut self, element: HtmlCanvasElement, dark_mode: bool
@@ -192,7 +186,7 @@ impl ChartManager {
     #[allow(clippy::too_many_arguments)]
     pub fn update(
         &mut self, canvas: HtmlCanvasElement, func_str_new: String, min_x: f32, max_x: f32, min_y: f32,
-        max_y: f32, num_interval: usize, resolution: i32, dark_mode: bool
+        max_y: f32, num_interval: usize, resolution: usize, dark_mode: bool
     ) -> Result<ChartOutput, JsValue> {
         let func_str: String = add_asterisks(func_str_new);
 
@@ -204,20 +198,6 @@ impl ChartManager {
             | (max_y != self.max_y);
 
 
-        if 0 > resolution {
-            panic!("resolution cannot be less than 0");
-        }
-
-        if underlying_update {
-            if min_x >= max_x {
-                panic!("min_x is greater than (or equal to) than max_x!");
-            }
-
-            if min_y >= max_y {
-                panic!("min_y is greater than (or equal to) than max_y!");
-            }
-        }
-
         if underlying_update | (self.resolution != resolution) {
             self.back_cache.invalidate();
         }

src/misc.rs

@@ -2,9 +2,11 @@ use wasm_bindgen::prelude::*;
 
 pub type DrawResult<T> = Result<T, Box<dyn std::error::Error>>;
 
-// EXTREMELY Janky function that tries to put asterisks in the proper places to be parsed. This is so cursed
+// EXTREMELY Janky function that tries to put asterisks in the proper places to be parsed. This is so cursed. But it works, and I hopefully won't ever have to touch it again. 
+// One limitation though, variables with multiple characters like `pi` cannot be multiplied (like `pipipipi` won't result in `pi*pi*pi*pi`). But that's such a niche use case (and that same thing could be done by using exponents) that it doesn't really matter.
 pub fn add_asterisks(function_in: String) -> String {
     let function = function_in.replace("log10(", "log("); // replace log10 with log
+    let valid_variables: Vec<char> = "xe".chars().collect();
     let letters: Vec<char>= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".chars().collect();
     let numbers: Vec<char> = "0123456789".chars().collect();
     let function_chars: Vec<char> = function.chars().collect();
@@ -12,6 +14,7 @@ pub fn add_asterisks(function_in: String) -> String {
     let mut output_string: String = String::new();
     let mut prev_chars: Vec<char> = Vec::new();
     for c in function_chars.clone() {
+        let mut add_asterisk: bool = false;
         let prev_chars_len = prev_chars.len();
         let curr_i: usize = func_chars_len-prev_chars_len;
 
@@ -41,32 +44,37 @@ pub fn add_asterisks(function_in: String) -> String {
         let prev_pi = (prev_prev_char == 'p') && (prev_char == 'i');
         let for_pi = (for_char == 'i') && (c == 'p');
 
+        
         if prev_char == ')' {
             if (c == '(') | numbers.contains(&c) | letters.contains(&c) {
-                output_string += "*";
+                add_asterisk = true;
             }
         } else if c == '(' {
-            if ((prev_char == 'x') | (prev_char == 'e') | (prev_char == ')') | numbers.contains(&prev_char)) && !letters.contains(&prev_prev_char) {
-                output_string += "*";
+            if (valid_variables.contains(&prev_char) | (prev_char == ')') | numbers.contains(&prev_char)) && !letters.contains(&prev_prev_char) {
+                add_asterisk = true;
             } else if prev_pi {
-                output_string += "*";
+                add_asterisk = true;
             }
         } else if numbers.contains(&prev_char) {
             if (c == '(') | letters.contains(&c) | for_pi {
-                output_string += "*";
+                add_asterisk = true;
             }
         } else if letters.contains(&c) {
             if numbers.contains(&prev_char) {
-                output_string += "*";
-            } else if ((c == 'x') | (c == 'e')) && ((prev_char == 'x') | (prev_char == 'e')) | prev_pi {
-                output_string += "*";
+                add_asterisk = true;
+            } else if (valid_variables.contains(&prev_char) && valid_variables.contains(&c)) | prev_pi {
+                add_asterisk = true;
             }
         } else if numbers.contains(&c) {
             if letters.contains(&prev_char) | prev_pi {
-                output_string += "*";
+                add_asterisk = true;
             }
         }
 
+        if add_asterisk {
+            output_string += "*";
+        }
+
         prev_chars.push(c);
         output_string += &c.to_string();
     }
@@ -153,6 +161,7 @@ impl<T> Cache<T> {
     pub fn is_valid(&self) -> bool { self.valid }
 }
 
+// Tests to make sure my cursed function works as intended
 #[test]
 fn asterisk_test() {
     assert_eq!(&add_asterisks("2x".to_string()), "2*x");