updated grapher

fixed issue where grapher would fail with functions due to some negative values being undefined

src/user/bin/grapher.rs

@@ -1,5 +1,5 @@
 use alloc::string::{String, ToString};
-use alloc::vec;
+use alloc::{format, vec};
 use alloc::vec::Vec;
 use alloc::boxed::Box;
 use async_trait::async_trait;
@@ -9,41 +9,56 @@ use crate::std::application::{Application, Error};
 use crate::std::frame::Element;
 use crate::std::io::{Screen, Stdin};
 
+const OFFSET_X: i64 = 40;
+const OFFSET_Y: i64 = 12;
+
 pub struct Grapher {
-    points: Vec<Point>,
+    points: Vec<PointF64>,
+    frame: Vec<Vec<char>>,
 }
 
-struct Point {
-    x: i16,
-    y: i16,
+struct PointF64 {
+    x: f64,
+    y: f64,
 }
+struct PointI64 {
+    x: i64,
+    y: i64,
+}
+
 
 #[async_trait]
 impl Application for Grapher {
     fn new() -> Self {
         Self {
             points: Vec::new(),
+            frame:  vec![vec![' '; 80]; 25],
         }
     }
     async fn run(&mut self, args: Vec<String>) -> Result<(), Error> {
         let mut equation: String = args.into_iter().collect();
         use super::calc;
 
-        for x in -40..40 {
+        for x in -4000..4000 {
+            let x = x as f64 / 100.0;
+
             let new_eq = equation.chars().map(|c| {
-                if c == 'x' { x.to_string() } else { c.to_string() }
+                if c == 'x' { format!("({})", x) } else { c.to_string() }
             }).collect::<String>();
 
-            let y = calc::calc_outer(new_eq).map_err(|_| Error::ApplicationError(String::from("failed to calculate")))?;
+            let fx = calc::calc_outer(new_eq).map_err(|_| Error::ApplicationError(String::from("failed to calculate")));
 
-            self.points.push(Point {
+            if let Ok(y) = fx {
+                self.render_point(PointF64 {
                     x,
-                y: y as i16,
+                    y,
                 })
+            }
+
         };
 
         Screen::application_mode();
-        self.render();
+        self.display();
 
         loop {
             match Stdin::keystroke().await {
@@ -58,17 +73,27 @@ impl Application for Grapher {
 }
 
 impl Grapher {
-    fn render(&self) {
-        let mut frame: Vec<Vec<char>> = vec![vec![' '; 80]; 25];
 
-        self.points.iter().filter(|i| i.x >= -40 && i.x < 40 && i.y >= -12 && i.y <= 12).for_each(|i| {
-            let offset_x = i.x + 40;
-            let offset_y = i.y + 12;
-            //println!("{} {}", i.x, i.y);
-            frame[24-offset_y as usize][offset_x as usize] = '*';
-        });
+    fn render_point(&mut self, point: PointF64) {
 
-        let mut elem = Element::generate(frame, (80, 25));
+        let point = PointI64 {
+            x: point.x as i64,
+            y: point.y as i64,
+        };
+
+        if point.x < -40 || point.x >= 40 || point.y < -12 || point.y >= 12 {
+            return;
+        }
+
+        let offset_x = point.x + OFFSET_X;
+        let offset_y = point.y + OFFSET_Y;
+
+        self.frame[24-offset_y as usize][offset_x as usize] = '*';
+    }
+
+
+    fn display(&mut self) {
+        let mut elem = Element::generate(self.frame.clone(), (80, 25));
         elem.render((0, 0));
     }
 }

src/user/bin/shell.rs

@@ -58,7 +58,12 @@ pub async fn eventloop() {
 }
 
 fn handle_error(e: Error) {
+    if let Error::ApplicationError(s) = e {
+        println!("there was an error! exiting program!: {}", s);
+    } else {
         println!("there was an error! exiting program!");
+
+    }
 }
 
 async fn exec() -> Result<(), Error> {