refactor and func -> proc rename

source/strpool/strpool.hon

@@ -3,7 +3,13 @@ import "@std/arraylist"
 import "@std/hashmap"
 import "@std/testing"
 
-StringId :: alias usize
+# cross-cutting concern, hence global singleton (owned by main.hon)
+strings StringPool = undefined
+
+InternError :: enum { out_of_space }
+
+StringId :: alias u32
+NoId :: maxval!(StringId)
 
 StringPool :: struct {
 	ids hashmap.StringHashMap(StringId) # string → id
@@ -11,7 +17,7 @@ StringPool :: struct {
 	allocator mem.Allocator
 }
 
-init func(allocator mem.Allocator) StringPool {
+init proc(allocator mem.Allocator) StringPool {
 	return StringPool{
 		ids = hashmap.init(allocator),
 		strings = arraylist.init(allocator),
@@ -19,7 +25,7 @@ init func(allocator mem.Allocator) StringPool {
 	}
 }
 
-deinit func(pool @mut StringPool) void {
+deinit proc(pool @mut StringPool) void {
 	hashmap.deinit(&pool.ids)
 	for pool.strings.items |str| {
 		mem.free(pool.allocator, str)
@@ -27,10 +33,12 @@ deinit func(pool @mut StringPool) void {
 	arraylist.deinit(&pool.strings)
 }
 
-intern func(pool @mut StringPool, str []u8) StringId ! mem.AllocError {
+intern proc(pool @mut StringPool, str []u8) StringId ! (mem.AllocError | InternError) {
 	if hashmap.get(&pool.ids, str) |id| return id
 
-	id :: pool.strings.items.len
+	if (pool.strings.items.len >= usize(NoId)) return .out_of_space
+	id StringId :: StringId(pool.strings.items.len)
+
 	owned_str []mut u8 :: try mem.alloc(u8, pool.allocator, str.len)
 	errdefer mem.free(pool.allocator, owned_str)
 	memcopy!(owned_str, str)
@@ -48,12 +56,12 @@ intern func(pool @mut StringPool, str []u8) StringId ! mem.AllocError {
 	return id
 }
 
-get_str func(pool @StringPool, id StringId) ?[]u8 {
-	if (id >= pool.strings.items.len) return null
-	return pool.strings.items[id]
+get_str proc(pool @StringPool, id StringId) ?[]u8 {
+	if (usize(id) >= pool.strings.items.len) return null
+	return pool.strings.items[usize(id)]
 }
 
-get_id func(pool @StringPool, str []u8) ?StringId {
+get_id proc(pool @StringPool, str []u8) ?StringId {
 	return hashmap.get(&pool.ids, str)
 }