Push checkmate through env

crates/compiler/checkmate/src/collector.rs

@@ -24,7 +24,7 @@ impl Collector {
         }
     }
 
-    pub fn unify(&mut self, subs: &s::Subs, to: s::Variable, from: s::Variable) {
+    pub fn unify(&mut self, subs: &s::Subs, from: s::Variable, to: s::Variable) {
         let to = to.as_schema(subs);
         let from = from.as_schema(subs);
         self.add_event(VariableEvent::Unify { to, from });
@@ -61,7 +61,7 @@ impl Collector {
         });
     }
 
-    pub fn start_unification(&mut self, subs: &s::Subs, left: &s::Variable, right: &s::Variable) {
+    pub fn start_unification(&mut self, subs: &s::Subs, left: s::Variable, right: s::Variable) {
         let left = left.as_schema(subs);
         let right = right.as_schema(subs);
         // TODO add mode
@@ -72,11 +72,32 @@ impl Collector {
             right,
             mode,
             subevents,
+            success: None,
         });
     }
 
-    pub fn end_unification(&mut self) {
+    pub fn end_unification(
+        &mut self,
+        subs: &s::Subs,
+        left: s::Variable,
+        right: s::Variable,
+        success: bool,
+    ) {
         let current_event = self.get_path_event();
+        match current_event {
+            Event::Unification {
+                left: l,
+                right: r,
+                success: s,
+                ..
+            } => {
+                assert_eq!(left.as_schema(subs), *l);
+                assert_eq!(right.as_schema(subs), *r);
+                assert!(s.is_none());
+                *s = Some(success);
+            }
+            _ => panic!("end_unification called when not in a unification"),
+        }
         assert!(matches!(current_event, Event::Unification { .. }));
         self.current_event_path.pop();
     }

crates/compiler/checkmate/src/lib.rs

@@ -5,6 +5,39 @@ mod schema;
 pub use collector::Collector;
 
 pub fn is_checkmate_enabled() -> bool {
-    let flag = std::env::var("ROC_CHECKMATE");
-    flag.as_deref() == Ok("1")
+    #[cfg(debug_assertions)]
+    {
+        let flag = std::env::var("ROC_CHECKMATE");
+        flag.as_deref() == Ok("1")
+    }
+    #[cfg(not(debug_assertions))]
+    {
+        false
+    }
+}
+
+#[macro_export]
+macro_rules! debug_checkmate {
+    ($opt_collector:expr, $cm:ident => $expr:expr) => {
+        #[cfg(debug_assertions)]
+        {
+            if let Some($cm) = $opt_collector.as_mut() {
+                $expr
+            }
+        }
+    };
+}
+
+#[macro_export]
+macro_rules! with_checkmate {
+    ($opt_collector:expr, { on => $on:expr, off => $off:expr, }) => {{
+        #[cfg(debug_assertions)]
+        {
+            $on
+        }
+        #[cfg(not(debug_assertions))]
+        {
+            $off
+        }
+    }};
 }

crates/compiler/checkmate/src/schema.rs

@@ -5,7 +5,7 @@ use serde::Serialize;
 #[derive(Serialize)]
 pub enum Constraint {}
 
-#[derive(Serialize)]
+#[derive(Serialize, Debug, PartialEq)]
 pub struct Variable(pub u32);
 
 #[derive(Serialize)]
@@ -197,6 +197,7 @@ pub enum Event {
         left: Variable,
         right: Variable,
         mode: UnificationMode,
+        success: Option<bool>,
         subevents: Vec<Event>,
     },
 }