From 9072e14686d0578b71e77426dd06c7270deb2267 Mon Sep 17 00:00:00 2001
From: T6 <t6@t6.fyi>
Date: Mon, 26 Feb 2024 09:33:03 -0500
Subject: [PATCH] add `Host::encode_tree` api, skipping intermediate `Def`
 representation (#64)

---
 src/host.rs | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/host.rs b/src/host.rs
index 2edcd684..fe879034 100644
--- a/src/host.rs
+++ b/src/host.rs
@@ -3,7 +3,7 @@
 
 use crate::{
   ast::{Book, Net, Tree},
-  run::{self, Addr, Def, Instruction, InterpretedDef, LabSet, Mode, Port, Tag, TrgId, Wire},
+  run::{self, Addr, Def, Instruction, InterpretedDef, LabSet, Mode, Port, Tag, Trg, TrgId, Wire},
   util::create_var,
 };
 use std::{
@@ -102,6 +102,51 @@ impl Host {
 
     net
   }
+
+  pub fn encode_tree<M: Mode>(&self, net: &mut run::Net<M>, trg: Trg, tree: &Tree) {
+    EncodeState { host: self, net, vars: Default::default() }.encode(trg, tree);
+
+    struct EncodeState<'c, 'n, M: Mode> {
+      host: &'c Host,
+      net: &'c mut run::Net<'n, M>,
+      vars: HashMap<&'c str, Trg>,
+    }
+
+    impl<'c, 'n, M: Mode> EncodeState<'c, 'n, M> {
+      fn encode(&mut self, trg: Trg, tree: &'c Tree) {
+        match tree {
+          Tree::Era => self.net.link_trg_port(trg, Port::ERA),
+          Tree::Num { val } => self.net.link_trg_port(trg, Port::new_num(*val)),
+          Tree::Ref { nam } => self.net.link_trg_port(trg, Port::new_ref(&self.host.defs[nam])),
+          Tree::Ctr { lab, lft, rgt } => {
+            let (l, r) = self.net.do_ctr(*lab, trg);
+            self.encode(l, lft);
+            self.encode(r, rgt);
+          }
+          Tree::Op2 { opr, lft, rgt } => {
+            let (l, r) = self.net.do_op2(*opr, trg);
+            self.encode(l, lft);
+            self.encode(r, rgt);
+          }
+          Tree::Op1 { opr, lft, rgt } => {
+            let r = self.net.do_op1(*opr, *lft, trg);
+            self.encode(r, rgt);
+          }
+          Tree::Mat { sel, ret } => {
+            let (s, r) = self.net.do_mat(trg);
+            self.encode(s, sel);
+            self.encode(r, ret);
+          }
+          Tree::Var { nam } => match self.vars.entry(nam) {
+            Entry::Occupied(e) => self.net.link_trg(e.remove(), trg),
+            Entry::Vacant(e) => {
+              e.insert(trg);
+            }
+          },
+        }
+      }
+    }
+  }
 }
 
 /// See [`Host::readback`].