From 0e69681ab82dfdaf7a0ec3b30249f588640ca617 Mon Sep 17 00:00:00 2001
From: Austen Adler <agadler@austenadler.com>
Date: Thu, 29 Apr 2021 22:08:33 -0400
Subject: [PATCH] Use method 1 for macro undos

---
 src/calc.rs | 96 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 56 insertions(+), 40 deletions(-)

diff --git a/src/calc.rs b/src/calc.rs
index 9a862d7..cf49dba 100644
--- a/src/calc.rs
+++ b/src/calc.rs
@@ -20,6 +20,7 @@ enum OpArgs {
 struct CalculatorStateChange {
     pop: OpArgs,
     push: OpArgs,
+    within_macro: bool,
 }
 
 pub struct Calculator<'a> {
@@ -171,6 +172,12 @@ impl<'a> Calculator<'a> {
                 // The macro needs to run in normal mode
                 self.state = CalculatorState::Normal;
 
+                // Add a no-op undo event as a stopgap for undo/redo operations (fixes undo after multiple macros running)
+                // self.direct_state_change(CalculatorStateChange {
+                //     pop: OpArgs::None,
+                //     push: OpArgs::None,
+                //     within_macro: self.within_macro(),
+                // })?;
                 // Record that we are running macro c
                 self.active_macros.insert(c);
                 for c in value.chars() {
@@ -271,36 +278,6 @@ impl<'a> Calculator<'a> {
         self.registers.iter()
     }
 
-    // pub fn push_constant(&mut self, key: char) -> CalculatorResult<()> {
-    //     match self.constants.get(&key) {
-    //         Some(CalculatorConstant { value, .. }) => {
-    //             let value = *value;
-    //             self.push(value)
-    //         }
-    //         None => Err(CalculatorError::NoSuchConstant(key)),
-    //     }
-    // }
-    // pub fn push_register(&mut self, key: char) -> CalculatorResult<()> {
-    //     match self.registers.get(&key) {
-    //         Some(f) => {
-    //             let f = *f;
-    //             self.push(f)
-    //         }
-    //         None => Err(CalculatorError::NoSuchRegister),
-    //     }
-    // }
-    // pub fn save_register(&mut self, key: char) -> CalculatorResult<()> {
-    //     let f = self.pop()?;
-    //     self.registers.insert(key, f);
-    //     Ok(())
-    // }
-    // pub fn get_macro(&mut self, key: char) -> Result<&CalculatorMacro<'a>, CalculatorError> {
-    //     match self.macros.get(&key) {
-    //         Some(m) => Ok(m),
-    //         None => Err(CalculatorError::NoSuchMacro(key)),
-    //     }
-    // }
-
     pub fn flush_l(&mut self) -> CalculatorResult<bool> {
         if self.l.is_empty() {
             Ok(false)
@@ -311,10 +288,14 @@ impl<'a> Calculator<'a> {
             Ok(true)
         }
     }
+    fn within_macro(&self) -> bool {
+        !self.active_macros.is_empty()
+    }
     fn push(&mut self, f: f64) -> CalculatorResult<()> {
         self.direct_state_change(CalculatorStateChange {
             pop: OpArgs::None,
             push: OpArgs::Unary(f),
+            within_macro: self.within_macro(),
         })
     }
     fn pop(&mut self) -> CalculatorResult<f64> {
@@ -322,6 +303,7 @@ impl<'a> Calculator<'a> {
         self.direct_state_change(CalculatorStateChange {
             pop: OpArgs::Unary(f),
             push: OpArgs::None,
+            within_macro: self.within_macro(),
         })?;
         Ok(f)
     }
@@ -366,18 +348,50 @@ impl<'a> Calculator<'a> {
             CalculatorOperation::Pow => self.binary_op(|[a, b]| OpArgs::Unary(b.powf(a))),
             CalculatorOperation::E => self.binary_op(|[a, b]| OpArgs::Unary(b * 10.0f64.powf(a))),
             CalculatorOperation::Undo => {
-                let s = self
-                    .undo_buf
-                    .pop()
-                    .ok_or_else(|| CalculatorError::EmptyHistory(String::from("undo")))?;
-                return self.apply_state_change(s, false);
+                let mut undone_already = false;
+                loop {
+                    if undone_already {
+                        let s = self
+                            .undo_buf
+                            .last()
+                            .ok_or_else(|| CalculatorError::EmptyHistory(String::from("undo")))?;
+                        if !s.within_macro {
+                            return Ok(());
+                        }
+                    }
+
+                    let s = self
+                        .undo_buf
+                        .pop()
+                        .ok_or_else(|| CalculatorError::EmptyHistory(String::from("undo")))?;
+                    let stop = !s.within_macro;
+                    self.apply_state_change(s, false)?;
+                    if stop {
+                        return Ok(());
+                    }
+                    undone_already = true;
+                }
             }
             CalculatorOperation::Redo => {
-                let s = self
-                    .redo_buf
-                    .pop()
-                    .ok_or_else(|| CalculatorError::EmptyHistory(String::from("redo")))?;
-                return self.apply_state_change(s, true);
+                let mut redone_already = false;
+                loop {
+                    let s = match self.redo_buf.pop() {
+                        None => {
+                            if redone_already {
+                                return Ok(());
+                            }
+                            return Err(CalculatorError::EmptyHistory(String::from("redo")));
+                        }
+                        Some(s) => {
+                            let stop = !s.within_macro;
+                            self.apply_state_change(s, true)?;
+                            if stop {
+                                return Ok(());
+                            }
+                            redone_already = true;
+                        }
+                    };
+                }
             }
             // Macros are a no-op as an operator
             CalculatorOperation::Macro(_) => {
@@ -399,6 +413,7 @@ impl<'a> Calculator<'a> {
         Ok(CalculatorStateChange {
             pop: OpArgs::Unary(*arg),
             push: op(*arg),
+            within_macro: self.within_macro(),
         })
     }
     fn binary_op(
@@ -418,6 +433,7 @@ impl<'a> Calculator<'a> {
         Ok(CalculatorStateChange {
             pop: OpArgs::Binary(args),
             push: op(args),
+            within_macro: self.within_macro(),
         })
     }