Added diceroll/modifier grouping

src/lib.rs

@@ -1,16 +1,17 @@
 use regex::Regex;
 use thiserror::Error;
 use anyhow::Result;
+use rand::Rng;
 
 #[cfg(test)]
 mod lib_test;
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 enum DiceFilter {
   DropLowest(i32), DropHighest(i32), KeepLowest(i32), KeepHighest(i32),
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 enum Segment {
   DiceRoll{
     op: char,
@@ -87,3 +88,48 @@ fn parse_dice_segments(cmd: &str) -> Result<Vec<Segment>> {
 
   regex.captures_iter(cmd).map(construct_dice_segment).collect()
 }
+
+#[derive(Debug, PartialEq, Clone)]
+struct RollWithModifier {
+  diceroll: Segment,
+  modifiers: Vec<Segment>
+}
+
+fn group_modifiers_to_dicerolls(segments: &[Segment]) -> Vec<RollWithModifier> {
+  let mut results = Vec::new();
+
+  let mut current_diceroll : Option<Segment> = None;
+  let mut current_modifiers = Vec::new();
+
+  for segment in segments {
+    if let Segment::DiceRoll {..} = segment {
+      if let Option::Some(current) = current_diceroll {
+        let with_modifier = RollWithModifier {
+          diceroll: current.clone(),
+          modifiers: current_modifiers.clone(),
+        };
+
+        current_modifiers.clear();
+
+        results.push(with_modifier);
+      }
+      current_diceroll = Some(segment.clone());
+    }
+    else if let Segment::Modifier { .. } = segment {
+      current_modifiers.push(segment.clone());
+    }
+  }
+
+  if let Option::Some(current) = current_diceroll {
+    let with_modifier = RollWithModifier {
+      diceroll: current.clone(),
+      modifiers: current_modifiers.clone(),
+    };
+
+    current_modifiers.clear();
+
+    results.push(with_modifier);
+  }
+
+  results
+}

src/lib_test.rs

@@ -1,7 +1,7 @@
 use super::*;
 
 #[test]
-fn test_roll_dice() {
+fn test_parse_dice_segments() {
   let mut results = parse_dice_segments("2d6").expect("Failed to unpack results");
   
   assert_eq!(results, vec![ Segment::DiceRoll{ op: '+', count: 2, size: 6, filter: None } ]);
@@ -34,3 +34,27 @@ fn test_roll_dice() {
     Segment::Modifier{ op: '/', amount: 2 },
   ]);
 }
+
+#[test]
+fn test_group_modifiers_to_dicerolls() {
+  let mut segments = parse_dice_segments("2d20 / 2 + 2 + 4d6 * 2 * 2").expect("Failed to unpack results");
+
+  let mut results = group_modifiers_to_dicerolls(&segments);
+
+  assert_eq!(results, vec![
+    RollWithModifier{
+      diceroll: Segment::DiceRoll{ op: '+', count: 2, size: 20, filter: None },
+      modifiers: vec![
+        Segment::Modifier{ op: '/', amount: 2 },
+        Segment::Modifier{ op: '+', amount: 2 },
+      ]
+    },
+    RollWithModifier{
+      diceroll: Segment::DiceRoll{ op: '+', count: 4, size: 6, filter: None },
+      modifiers: vec![
+        Segment::Modifier{ op: '*', amount: 2 },
+        Segment::Modifier{ op: '*', amount: 2 },
+      ]
+    },
+  ]);
+}