From 9b26559c8273fd4de6aa6a740d6472a665446274 Mon Sep 17 00:00:00 2001
From: Charlie Stanton <charlie@shtanton.xyz>
Date: Tue, 25 Apr 2023 09:26:34 +0100
Subject: Refines storing and loading to use ids generated when the subex is
 compiled instead of the runes

---
 subex/main.go | 49 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 11 deletions(-)

(limited to 'subex/main.go')

diff --git a/subex/main.go b/subex/main.go
index 5aedd09..635b1de 100644
--- a/subex/main.go
+++ b/subex/main.go
@@ -4,26 +4,53 @@ import (
 	"main/walk"
 )
 
+type Transducer struct {
+	storeSize int
+	initialState SubexState
+}
+
+type StoreItem struct {}
 // Where slots are stored
-type Store map[rune][]walk.Atom
+type Store [][]walk.Atom
 // Return a new store with all the data from this one
 func (store Store) clone() Store {
-	newStore := make(Store)
-	for key, val := range store {
-		newStore[key] = val
-	}
+	newStore := make([][]walk.Atom, len(store))
+	copy(newStore, store)
 	return newStore
 }
 // Return a copy of this store but with an additional slot set
-func (store Store) withValue(key rune, value []walk.Atom) Store {
+func (store Store) withValue(key int, value []walk.Atom) Store {
 	newStore := store.clone()
 	newStore[key] = value
 	return newStore
 }
 
+type SlotMap struct {
+	nextId int
+	ids map[rune]int
+}
+func (m *SlotMap) getId(slot rune) int {
+	id, exists := m.ids[slot]
+	if exists {
+		return id
+	}
+	id = m.nextId
+	m.nextId++
+	m.ids[slot] = id
+	return id
+}
+
 // Compile the SubexAST into a transducer SubexState that can be run
-func CompileTransducer(transducerAst SubexAST) SubexState {
-	return transducerAst.compileWith(&SubexNoneState{})
+func CompileTransducer(transducerAst SubexAST) Transducer {
+	slotMap := SlotMap {
+		nextId: 0,
+		ids: make(map[rune]int),
+	}
+	initial := transducerAst.compileWith(&SubexNoneState{}, &slotMap)
+	return Transducer {
+		storeSize: slotMap.nextId,
+		initialState: initial,
+	}
 }
 
 // An immutable stack for outputting to
@@ -93,14 +120,14 @@ func pruneStates(states []SubexBranch) (newStates []SubexBranch) {
 }
 
 // Run the subex transducer
-func RunTransducer(transducer SubexState, input []walk.Atom) (output []walk.Atom, err bool) {
+func RunTransducer(transducer Transducer, input []walk.Atom) (output []walk.Atom, err bool) {
 	states := []SubexBranch{{
-		state: transducer,
+		state: transducer.initialState,
 		outputStack: OutputStack {
 			head: nil,
 			tail: nil,
 		},
-		store: make(Store),
+		store: make([][]walk.Atom, transducer.storeSize),
 	}}
 	for _, piece := range input {
 		var newStates []SubexBranch
-- 
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