get roller working correctly

src/bin/dicebot-roll.rs

@@ -1,9 +1,13 @@
+use axfive_matrix_dicebot::dice::parser::parse_element_expression;
+use axfive_matrix_dicebot::roll::{Roll, Rolled};
 use std::error::Error;
 
-fn main() -> Result<(), Box<dyn Error>> {
-    let _roll_string = std::env::args().skip(1).collect::<Vec<String>>().join(" ");
-    // first regex needs to be different because the sign is mandatory for the rest
-    //let expression = parse_expression(&roll_string);
-    //println!("{:?}", expression);
+fn main() -> Result<(), String> {
+    let roll_string = std::env::args().skip(1).collect::<Vec<String>>().join(" ");
+    let (_tail, expression) = match parse_element_expression(&roll_string) {
+        Ok(response) => response,
+        Err(e) => return Err(e.to_string()),
+    };
+    println!("{}", expression.roll());
     Ok(())
 }

src/dice/parser.rs

@@ -7,7 +7,7 @@ use nom::{
     tag, IResult,
 };
 
-use crate::dice::{Dice, Element, SignedElement, ElementExpression};
+use crate::dice::{Dice, Element, ElementExpression, SignedElement};
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 enum Sign {
@@ -78,7 +78,7 @@ fn parse_signed_element(input: &str) -> IResult<&str, SignedElement> {
 }
 
 // Parse a full element expression.  Eats whitespace.
-fn parse_element_expression(input: &str) -> IResult<&str, ElementExpression> {
+pub fn parse_element_expression(input: &str) -> IResult<&str, ElementExpression> {
     named!(first_element(&str) -> SignedElement, alt!(
             parse_signed_element => { |e| e } |
             parse_element => { |e| SignedElement::Positive(e) }
@@ -180,4 +180,3 @@ mod tests {
         );
     }
 }
-

src/roll.rs

@@ -1,5 +1,8 @@
 use rand::prelude::*;
+use std::ops::{Deref, DerefMut};
 use crate::dice;
+use std::fmt;
+use std::string::ToString;
 
 pub trait Roll {
     type Output;
@@ -7,33 +10,237 @@ pub trait Roll {
     fn roll(&self) -> Self::Output;
 }
 
-impl Roll for dice::Dice {
-    type Output = u32; 
+pub trait Rolled {
+    fn rolled_value(&self) -> i32;
+}
 
-    fn roll(&self) -> u32 {
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct DiceRoll(Vec<u32>);
+
+impl DiceRoll {
+    pub fn rolls(&self) -> &[u32] {
+        &self.0
+    }
+
+    pub fn total(&self) -> u32 {
+        self.0.iter().sum()
+    }
+}
+
+impl Rolled for DiceRoll {
+    fn rolled_value(&self) -> i32 {
+        self.total() as i32
+    }
+}
+
+impl fmt::Display for DiceRoll {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.rolled_value())?;
+        let rolls = self.rolls();
+        let mut iter = rolls.iter();
+        if let Some(first) = iter.next() {
+            write!(f, " ({}", first)?;
+            for roll in iter {
+                write!(f, " + {}", roll)?;
+            }
+            write!(f, ")")?;
+        }
+        Ok(())
+    }
+}
+
+impl Roll for dice::Dice {
+    type Output = DiceRoll; 
+
+    fn roll(&self) -> DiceRoll {
         let mut rng = rand::thread_rng();
-        (0..self.count).map(|_| rng.gen_range(1, self.sides + 1)).sum()
+        let rolls = (0..self.count).map(|_| rng.gen_range(1, self.sides + 1)).collect();
+        DiceRoll(rolls)
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum ElementRoll {
+    Dice(DiceRoll),
+    Bonus(u32),
+}
+
+impl Rolled for ElementRoll {
+    fn rolled_value(&self) -> i32 {
+        match self {
+            ElementRoll::Dice(d) => d.rolled_value(),
+            ElementRoll::Bonus(b) => *b as i32,
+        }
     }
 }
 
 impl Roll for dice::Element {
-    type Output = u32; 
+    type Output = ElementRoll; 
 
-    fn roll(&self) -> u32 {
+    fn roll(&self) -> ElementRoll {
         match self {
-            dice::Element::Dice(d) => d.roll(),
-            dice::Element::Bonus(b) => *b,
+            dice::Element::Dice(d) => ElementRoll::Dice(d.roll()),
+            dice::Element::Bonus(b) => ElementRoll::Bonus(*b),
+        }
+    }
+}
+
+impl fmt::Display for ElementRoll {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ElementRoll::Dice(d) => write!(f, "{}", d),
+            ElementRoll::Bonus(b) => write!(f, "{}", b),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum SignedElementRoll {
+    Positive(ElementRoll),
+    Negative(ElementRoll),
+}
+
+impl Rolled for SignedElementRoll {
+    fn rolled_value(&self) -> i32 {
+        match self {
+            SignedElementRoll::Positive(e) => e.rolled_value(),
+            SignedElementRoll::Negative(e) => -e.rolled_value(),
         }
     }
 }
 
 impl Roll for dice::SignedElement {
-    type Output = i32; 
+    type Output = SignedElementRoll; 
 
-    fn roll(&self) -> i32 {
+    fn roll(&self) -> SignedElementRoll {
         match self {
-            dice::SignedElement::Positive(e) => e.roll() as i32,
-            dice::SignedElement::Negative(e) => -(e.roll() as i32),
+            dice::SignedElement::Positive(e) => SignedElementRoll::Positive(e.roll()),
+            dice::SignedElement::Negative(e) => SignedElementRoll::Negative(e.roll()),
         }
     }
 }
+
+impl fmt::Display for SignedElementRoll {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            SignedElementRoll::Positive(e) => write!(f, "{}", e),
+            SignedElementRoll::Negative(e) => write!(f, "-{}", e),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct ElementExpressionRoll(Vec<SignedElementRoll>);
+
+impl Deref for ElementExpressionRoll {
+    type Target = Vec<SignedElementRoll>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ElementExpressionRoll {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl Rolled for ElementExpressionRoll {
+    fn rolled_value(&self) -> i32 {
+        self.iter().map(Rolled::rolled_value).sum()
+    }
+}
+
+impl Roll for dice::ElementExpression {
+    type Output = ElementExpressionRoll; 
+
+    fn roll(&self) -> ElementExpressionRoll {
+        ElementExpressionRoll(self.iter().map(Roll::roll).collect())
+    }
+}
+
+impl fmt::Display for ElementExpressionRoll {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.len() > 1 {
+            write!(f, "{}", self.rolled_value())?;
+            let mut iter = self.0.iter();
+            if let Some(first) = iter.next() {
+                write!(f, " ({}", first)?;
+                for roll in iter {
+                    match roll {
+                        SignedElementRoll::Positive(e) => write!(f, " + {}", e)?,
+                        SignedElementRoll::Negative(e) => write!(f, " - {}", e)?,
+                    }
+                }
+                write!(f, ")")?;
+            }
+            Ok(())
+        } else if self.len() > 0 {
+            // For a single item, just show the inner item to avoid redundancy
+            let first = self.0.iter().next().unwrap();
+            write!(f, "{}", first)
+        } else {
+            write!(f, "0")
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn dice_roll_display_test() {
+        assert_eq!(DiceRoll(vec![1, 3, 4]).to_string(), "8 (1 + 3 + 4)");
+        assert_eq!(DiceRoll(vec![]).to_string(), "0");
+        assert_eq!(DiceRoll(vec![4, 7, 2, 10]).to_string(), "23 (4 + 7 + 2 + 10)");
+    }
+
+    #[test]
+    fn element_roll_display_test() {
+        assert_eq!(ElementRoll::Dice(DiceRoll(vec![1, 3, 4])).to_string(), "8 (1 + 3 + 4)");
+        assert_eq!(ElementRoll::Bonus(7).to_string(), "7");
+    }
+
+    #[test]
+    fn signed_element_roll_display_test() {
+        assert_eq!(SignedElementRoll::Positive(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))).to_string(), "8 (1 + 3 + 4)");
+        assert_eq!(SignedElementRoll::Negative(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))).to_string(), "-8 (1 + 3 + 4)");
+        assert_eq!(SignedElementRoll::Positive(ElementRoll::Bonus(7)).to_string(), "7");
+        assert_eq!(SignedElementRoll::Negative(ElementRoll::Bonus(7)).to_string(), "-7");
+    }
+
+    #[test]
+    fn element_expression_roll_display_test() {
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Positive(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))),
+            ]).to_string(), "8 (1 + 3 + 4)");
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Negative(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))),
+            ]).to_string(), "-8 (1 + 3 + 4)");
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Positive(ElementRoll::Bonus(7)),
+            ]).to_string(), "7");
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Negative(ElementRoll::Bonus(7)),
+            ]).to_string(), "-7");
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Positive(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))),
+                SignedElementRoll::Negative(ElementRoll::Dice(DiceRoll(vec![1, 2]))),
+                SignedElementRoll::Positive(ElementRoll::Bonus(4)),
+                SignedElementRoll::Negative(ElementRoll::Bonus(7)),
+            ]).to_string(), "2 (8 (1 + 3 + 4) - 3 (1 + 2) + 4 - 7)");
+        assert_eq!(
+            ElementExpressionRoll(vec![
+                SignedElementRoll::Negative(ElementRoll::Dice(DiceRoll(vec![1, 3, 4]))),
+                SignedElementRoll::Positive(ElementRoll::Dice(DiceRoll(vec![1, 2]))),
+                SignedElementRoll::Negative(ElementRoll::Bonus(4)),
+                SignedElementRoll::Positive(ElementRoll::Bonus(7)),
+            ]).to_string(), "-2 (-8 (1 + 3 + 4) + 3 (1 + 2) - 4 + 7)");
+    }
+}