From 9f55a12ab2efb1df00c68105a5a7f1520047b20a Mon Sep 17 00:00:00 2001
From: Griffin Berlstein <griffin@berlste.in>
Date: Thu, 16 May 2024 12:52:18 -0400
Subject: [PATCH] par stuff (#2043)

---
 .../src/flatten/structures/environment/env.rs | 32 ++++++++++++++++++-
 .../structures/environment/program_counter.rs | 16 +++++++---
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/interp/src/flatten/structures/environment/env.rs b/interp/src/flatten/structures/environment/env.rs
index b0e5b82e97..22907eca5a 100644
--- a/interp/src/flatten/structures/environment/env.rs
+++ b/interp/src/flatten/structures/environment/env.rs
@@ -578,6 +578,9 @@ impl<'a> Simulator<'a> {
         // program counter as the size
         let mut leaf_nodes = vec![];
 
+        let mut par_map = std::mem::take(self.env.pc.par_map_mut());
+        let mut new_nodes = vec![];
+
         self.env.pc.vec_mut().retain_mut(|node| {
             // just considering a single node case for the moment
             match &self.env.ctx.primary[node.control_node_idx] {
@@ -590,7 +593,29 @@ impl<'a> Simulator<'a> {
                         node.mutate_into_next(self.env.ctx)
                     }
                 }
-                ControlNode::Par(_par) => todo!("not ready for par yet"),
+                ControlNode::Par(par) => {
+                    if par_map.contains_key(node) {
+                        let count = par_map.get_mut(node).unwrap();
+                        *count -= 1;
+                        if *count == 0 {
+                            par_map.remove(node);
+                            node.mutate_into_next(self.env.ctx)
+                        } else {
+                            false
+                        }
+                    } else {
+                        par_map.insert(
+                            node.clone(),
+                            par.stms().len().try_into().expect(
+                                "More than (2^16 - 1 threads) in a par block. Are you sure this is a good idea?",
+                            ),
+                        );
+                        new_nodes.extend(
+                            par.stms().iter().map(|x| node.new_retain_comp(*x)),
+                        );
+                        false
+                    }
+                }
                 ControlNode::If(i) => {
                     if i.cond_group().is_some() {
                         todo!("if statement has a with clause")
@@ -675,6 +700,11 @@ impl<'a> Simulator<'a> {
             }
         });
 
+        // insert all the new nodes from the par into the program counter
+        self.env.pc.vec_mut().extend(new_nodes);
+        // return the par map to the program counter
+        *self.env.pc.par_map_mut() = par_map;
+
         self.undef_all_ports();
 
         for node in &leaf_nodes {
diff --git a/interp/src/flatten/structures/environment/program_counter.rs b/interp/src/flatten/structures/environment/program_counter.rs
index f93b01fbf9..c67c5d51e5 100644
--- a/interp/src/flatten/structures/environment/program_counter.rs
+++ b/interp/src/flatten/structures/environment/program_counter.rs
@@ -145,7 +145,7 @@ impl SearchPath {
                         // par's child count should be decremented. The latter
                         // seems more promising but I need to think on it more
 
-                        todo!("need to deal with par")
+                        return Some(*node);
                     }
                     ControlNode::If(_) => {
                         // there is nothing to do when ascending to an if as it
@@ -322,7 +322,7 @@ pub type ChildCount = u16;
 #[derive(Debug, Default)]
 pub(crate) struct ProgramCounter {
     vec: Vec<ControlPoint>,
-    _par_map: HashMap<ControlPoint, ChildCount>,
+    par_map: HashMap<ControlPoint, ChildCount>,
 }
 
 // we need a few things from the program counter
@@ -349,7 +349,7 @@ impl ProgramCounter {
 
         Self {
             vec,
-            _par_map: HashMap::new(),
+            par_map: HashMap::new(),
         }
     }
 
@@ -365,9 +365,17 @@ impl ProgramCounter {
         self.vec.iter_mut()
     }
 
-    pub(crate) fn vec_mut(&mut self) -> &mut Vec<ControlPoint> {
+    pub fn vec_mut(&mut self) -> &mut Vec<ControlPoint> {
         &mut self.vec
     }
+
+    pub fn par_map_mut(&mut self) -> &mut HashMap<ControlPoint, ChildCount> {
+        &mut self.par_map
+    }
+
+    pub fn _par_map(&self) -> &HashMap<ControlPoint, ChildCount> {
+        &self.par_map
+    }
 }
 
 impl<'a> IntoIterator for &'a ProgramCounter {