Various code improvements

src/calc.rs

@@ -2,15 +2,11 @@ pub mod constants;
 pub mod errors;
 pub mod operations;
 
-use constants::CalculatorConstant;
+use constants::{
-use constants::CalculatorConstants;
+    CalculatorConstant, CalculatorConstants, CalculatorConstantsIter, CalculatorMacro,
-use constants::CalculatorConstantsIter;
+    CalculatorMacros, CalculatorMacrosIter, CalculatorRegisters, CalculatorRegistersIter,
-use constants::CalculatorMacro;
+};
-use constants::CalculatorMacros;
+use errors::{CalculatorError, CalculatorResult};
-use constants::CalculatorMacrosIter;
-use constants::CalculatorRegisters;
-use constants::CalculatorRegistersIter;
-use errors::CalculatorError;
 use operations::CalculatorOperation;
 use std::collections::VecDeque;
 
@@ -108,7 +104,7 @@ impl<'a> Calculator<'a> {
         self.registers.iter()
     }
 
-    pub fn push_constant(&mut self, key: char) -> Result<(), CalculatorError> {
+    pub fn push_constant(&mut self, key: char) -> CalculatorResult<()> {
         match self.constants.get(&key) {
             Some(CalculatorConstant { value, .. }) => {
                 let value = *value;
@@ -117,7 +113,7 @@ impl<'a> Calculator<'a> {
             None => Err(CalculatorError::NoSuchConstant),
         }
     }
-    pub fn push_register(&mut self, key: char) -> Result<(), CalculatorError> {
+    pub fn push_register(&mut self, key: char) -> CalculatorResult<()> {
         match self.registers.get(&key) {
             Some(f) => {
                 let f = *f;
@@ -127,7 +123,7 @@ impl<'a> Calculator<'a> {
         }
     }
     // TODO: Use hashmap
-    pub fn save_register(&mut self, key: char) -> Result<(), CalculatorError> {
+    pub fn save_register(&mut self, key: char) -> CalculatorResult<()> {
         let f = self.pop()?;
         self.registers.insert(key, f);
         Ok(())
@@ -139,13 +135,13 @@ impl<'a> Calculator<'a> {
         }
     }
 
-    pub fn push(&mut self, f: f64) -> Result<(), CalculatorError> {
+    pub fn push(&mut self, f: f64) -> CalculatorResult<()> {
         self.direct_state_change(CalculatorStateChange {
             pop: OpArgs::None,
             push: OpArgs::Unary(f),
         })
     }
-    pub fn pop(&mut self) -> Result<f64, CalculatorError> {
+    pub fn pop(&mut self) -> CalculatorResult<f64> {
         let f = self.checked_get(0)?;
         self.direct_state_change(CalculatorStateChange {
             pop: OpArgs::Unary(f),
@@ -157,7 +153,7 @@ impl<'a> Calculator<'a> {
         &self.stack
     }
     //TODO: VecDeque could have other types
-    pub fn op(&mut self, op: CalculatorOperation) -> Result<(), CalculatorError> {
+    pub fn op(&mut self, op: CalculatorOperation) -> CalculatorResult<()> {
         let state_change = match op {
             CalculatorOperation::Add => self.binary_op(|[a, b]| OpArgs::Unary(b + a)),
             CalculatorOperation::Subtract => self.binary_op(|[a, b]| OpArgs::Unary(b - a)),
@@ -210,7 +206,7 @@ impl<'a> Calculator<'a> {
     fn unary_op(
         &mut self,
         op: impl FnOnce(f64) -> OpArgs,
-    ) -> Result<CalculatorStateChange, CalculatorError> {
+    ) -> CalculatorResult<CalculatorStateChange> {
         let arg = self
             .stack
             .get(0)
@@ -223,7 +219,7 @@ impl<'a> Calculator<'a> {
     fn binary_op(
         &mut self,
         op: impl FnOnce([f64; 2]) -> OpArgs,
-    ) -> Result<CalculatorStateChange, CalculatorError> {
+    ) -> CalculatorResult<CalculatorStateChange> {
         let args: [f64; 2] = [
             *self
                 .stack
@@ -240,7 +236,7 @@ impl<'a> Calculator<'a> {
         })
     }
 
-    fn direct_state_change(&mut self, c: CalculatorStateChange) -> Result<(), CalculatorError> {
+    fn direct_state_change(&mut self, c: CalculatorStateChange) -> CalculatorResult<()> {
         let result = self.apply_state_change(c, true);
         if result.is_ok() {
             // Clear the redo buffer since this was a direct state change
@@ -253,7 +249,7 @@ impl<'a> Calculator<'a> {
         &mut self,
         c: CalculatorStateChange,
         forward: bool,
-    ) -> Result<(), CalculatorError> {
+    ) -> CalculatorResult<()> {
         let (to_pop, to_push) = if forward {
             (&c.pop, &c.push)
         } else {
@@ -313,7 +309,7 @@ impl<'a> Calculator<'a> {
         Ok(())
     }
 
-    fn stack_eq(&self, idx: usize, value: f64) -> Result<(), CalculatorError> {
+    fn stack_eq(&self, idx: usize, value: f64) -> CalculatorResult<()> {
         if (self.checked_get(idx)? - value).abs() > f64::EPSILON {
             Err(CalculatorError::CorruptStateChange(format!(
                 "Stack index {} should be {}, but is {}",
@@ -326,7 +322,7 @@ impl<'a> Calculator<'a> {
         }
     }
 
-    fn checked_get(&self, idx: usize) -> Result<f64, CalculatorError> {
+    fn checked_get(&self, idx: usize) -> CalculatorResult<f64> {
         match self.stack.get(idx) {
             None => Err(CalculatorError::NotEnoughStackEntries),
             Some(r) => Ok(*r),

src/calc/errors.rs

@@ -1,5 +1,7 @@
 use std::fmt;
 
+pub type CalculatorResult<T> = Result<T, CalculatorError>;
+
 pub enum CalculatorError {
     ArithmeticError,
     NotEnoughStackEntries,

src/calc/operations.rs

@@ -1,4 +1,4 @@
-use super::errors::CalculatorError;
+use super::errors::{CalculatorError, CalculatorResult};
 
 pub enum CalculatorOperation {
     Add,
@@ -31,7 +31,7 @@ pub enum CalculatorOperation {
 }
 
 impl CalculatorOperation {
-    pub fn from_char(key: char) -> Result<CalculatorOperation, CalculatorError> {
+    pub fn from_char(key: char) -> CalculatorResult<CalculatorOperation> {
         match key {
             '+' => Ok(CalculatorOperation::Add),
             '-' => Ok(CalculatorOperation::Subtract),

src/main.rs

@@ -4,7 +4,7 @@
 mod calc;
 mod util;
 
-use calc::errors::CalculatorError;
+use calc::errors::{CalculatorError, CalculatorResult};
 use calc::operations::CalculatorOperation;
 use calc::Calculator;
 use std::cmp;
@@ -251,7 +251,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     }
 }
 
-fn handle_key(app: &mut App, events: &Events, key: Key) -> Result<bool, CalculatorError> {
+fn handle_key(app: &mut App, events: &Events, key: Key) -> CalculatorResult<bool> {
     match &app.state {
         AppState::Calculator => match key {
             Key::Char('q') => {
@@ -275,17 +275,22 @@ fn handle_key(app: &mut App, events: &Events, key: Key) -> Result<bool, Calculat
             Key::Char(c @ '0'..='9') => {
                 app.input.push(c);
             }
-            Key::Char(c @ 'e') | Key::Char(c @ '.') => {
+            Key::Char('e') => {
                 if app.input.is_empty() {
-                    if let Ok(f) = app.calculator.pop() {
+                    let f = app
+                        .calculator
+                        .pop()
+                        .or(Err(CalculatorError::NotEnoughStackEntries))?;
                     app.input = f.to_string();
-                    } else {
-                        return Err(CalculatorError::NotEnoughStackEntries);
-                    }
                 }
 
-                if !app.input.contains(c) {
+                if !app.input.contains('e') {
-                    app.input.push(c);
+                    app.input.push('e');
+                }
+            }
+            Key::Char('.') => {
+                if !app.input.contains('.') {
+                    app.input.push('.');
                 }
             }
             Key::Char('\n') | Key::Char(' ') => {
@@ -366,14 +371,14 @@ fn handle_key(app: &mut App, events: &Events, key: Key) -> Result<bool, Calculat
                 if !app.input.is_empty() {
                     //TODO: A better way to do this
                     //Can use calc_operation in the future. Already performs this check
-                    if let Ok(f) = app.input.parse::<f64>() {
+                    let f = app
-                        match app.calculator.push(f) {
+                        .input
-                            Ok(()) => app.input.clear(),
+                        .parse::<f64>()
-                            Err(e) => return Err(e),
+                        .or(Err(CalculatorError::ParseError))?;
-                        }
+                    app.calculator.push(f).and_then(|()| {
-                    } else {
+                        app.input.clear();
-                        return Err(CalculatorError::ParseError);
+                        Ok(())
-                    }
+                    })?;
                 }
 
                 // TODO: Handle macros internally to the calculator
@@ -387,15 +392,15 @@ fn handle_key(app: &mut App, events: &Events, key: Key) -> Result<bool, Calculat
     return Ok(false);
 }
 
-fn calc_operation(app: &mut App, c: char) -> Result<(), CalculatorError> {
+fn calc_operation(app: &mut App, c: char) -> CalculatorResult<()> {
     let op = CalculatorOperation::from_char(c)?;
     if !app.input.is_empty() {
-        if let Ok(f) = app.input.parse::<f64>() {
+        let f = app
+            .input
+            .parse::<f64>()
+            .or(Err(CalculatorError::ParseError))?;
         app.calculator.push(f)?;
         app.input.clear();
-        } else {
-            return Err(CalculatorError::ParseError);
-        }
     }
 
     app.calculator.op(op)