feat: add stall detection with halt and loop modes

README.md

@@ -92,6 +92,7 @@ You can also use the `home-manager` module to install and configure `trmt`. Firs
     config = {
       simulation = {
         autoplay = true;
+        mode = "halt";
         heads = 3;
         rule = "RL";
         speed_ms = 20;
@@ -193,6 +194,7 @@ https://github.com/user-attachments/assets/eefc272b-09b2-4c9c-93dc-984c1ae60ed0
 ```toml
 [simulation]
 autoplay = true                     # If true, simulation starts running automatically on launch, reset and config reload
+mode = "halt"                       # What happens when a run stalls or repeats exactly. "halt" = pause, "loop" = restart
 heads = 3                           # Number of heads on initialization
 rule = "RL"                         # Rules for the simulation
 speed_ms = 20                       # Simulation speed in milliseconds

examples/builders.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 6
 rule = "L1>1,R1>1:R1>1,R0>0"
 speed_ms = 8.0

examples/critter_highway.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 6
 rule = "WRSWNL"
 speed_ms = 10.0

examples/dotgrid.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 6
 rule = "R1>1,L0>2,U1>0:D0>0,R1>1:L0>1,R1>2"
 speed_ms = 30.0

examples/factory.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 4
 rule = "R1>1,L0>1:U1>0,D0>1"
 speed_ms = 5.0

examples/matrix.md

@@ -6,6 +6,7 @@ Inspired by [cmatrix](https://github.com/abishekvashok/cmatrix) and [unimatrix](
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 128
 rule = "S"
 speed_ms = 100.0

examples/pipedream.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 4
 rule = "DUWLWWRWD"
 speed_ms = 10.0

examples/scaffold.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 4
 rule = "DULNESWUNW"
 speed_ms = 10.0

examples/transistor.md

@@ -5,6 +5,7 @@
 ```toml
 [simulation]
 autoplay = true
+mode = "halt"
 heads = 5
 rule = "WUNRSL"
 speed_ms = 9.0

nix/modules/home-manager.nix

@@ -21,6 +21,7 @@ in {
         {
           simulation = {
             autoplay = true;
+            mode = "halt";
             heads = 3;
             rule = "RL";
             speed_ms = 20;
@@ -39,11 +40,12 @@ in {
             cell_char = "░░";
             randomize_heads = false;
             randomize_trails = false;
-            direction_based_chars = false
+            direction_based_chars = false;
           };
           controls = {
             quit = "q";
             toggle = " ";
+            step = ".";
             reset = "r";
             faster = "+";
             slower = "-";

src/config/mod.rs

@@ -7,7 +7,7 @@ use ratatui::style::Color;
 use serde::{Deserialize, Serialize};
 use std::{error::Error, fs, path::PathBuf};
 
-pub use simulation::SimulationConfig;
+pub use simulation::{SimulationConfig, SimMode};
 pub use display::{DisplayConfig, CharData};
 pub use controls::ControlsConfig;
 

src/config/simulation.rs

@@ -2,6 +2,14 @@ use serde::{Deserialize, Serialize};
 use rand::Rng;
 use std::collections::{HashSet};
 
+// What to do when detection proves a run is done
+#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum SimMode {
+    Halt,
+    Loop,
+}
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct SimulationConfig {
     #[serde(default = "autoplay")]
@@ -18,6 +26,8 @@ pub struct SimulationConfig {
     pub color_cells: bool,
     #[serde(default = "seed")]
     pub seed: Option<String>,
+    #[serde(default = "mode")]
+    pub mode: SimMode,
 }
 
 // Default functions
@@ -28,6 +38,7 @@ fn speed() -> f64 { 5.0 }
 fn trail_length() -> usize { 16 }
 fn color_cells() -> bool { true }
 fn seed() -> Option<String> { Some(String::new()) }
+fn mode() -> SimMode { SimMode::Halt }
 
 impl Default for SimulationConfig {
     fn default() -> Self {
@@ -39,6 +50,7 @@ impl Default for SimulationConfig {
             trail_length: trail_length(),
             color_cells: color_cells(),
             seed: seed(),
+            mode: mode(),
         }
     }
 }
@@ -166,7 +178,7 @@ impl SimulationConfig {
 
         transitions.join(",")
     }
-    
+
     // Score rules based on potential for interesting behavior
     fn score_rule_potential(rule: &str) -> i32 {
         let mut score = 0;
@@ -194,4 +206,22 @@ impl SimulationConfig {
 
         score
     }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn mode_parses_from_toml_and_defaults_to_halt() {
+        let parsed: SimulationConfig = toml::from_str("mode = \"loop\"").unwrap();
+        assert_eq!(parsed.mode, SimMode::Loop);
+        let empty: SimulationConfig = toml::from_str("").unwrap();
+        assert_eq!(empty.mode, SimMode::Halt);
+        assert_eq!(SimulationConfig::default().mode, SimMode::Halt);
+        assert!(toml::from_str::<SimulationConfig>("mode = \"disco\"").is_err());
+        // create_example_config serializes this, so the TOML name has to round-trip
+        let serialized = toml::to_string(&SimulationConfig::default()).unwrap();
+        assert!(serialized.contains("mode = \"halt\""), "{serialized}");
+    }
 }