From 9738b3454639ddf3ae46186a5c6ba671fe9a6861 Mon Sep 17 00:00:00 2001
From: Bruce Hill <bruce@bruce-hill.com>
Date: Sun, 5 Oct 2025 16:24:59 -0400
Subject: Add serialization and deserialization by coercion to/from [Byte]

---
 src/compile/expressions.c |  6 ++++--
 src/compile/promotions.c  | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

(limited to 'src/compile')

diff --git a/src/compile/expressions.c b/src/compile/expressions.c
index 098ed4ca..4e6c720f 100644
--- a/src/compile/expressions.c
+++ b/src/compile/expressions.c
@@ -12,8 +12,10 @@
 public
 Text_t compile_maybe_incref(env_t *env, ast_t *ast, type_t *t) {
     if (is_idempotent(ast) && can_be_mutated(env, ast)) {
-        if (t->tag == ListType) return Texts("LIST_COPY(", compile_to_type(env, ast, t), ")");
-        else if (t->tag == TableType) return Texts("TABLE_COPY(", compile_to_type(env, ast, t), ")");
+        type_t *actual = get_type(env, ast);
+        if (t->tag == ListType && type_eq(t, actual)) return Texts("LIST_COPY(", compile_to_type(env, ast, t), ")");
+        else if (t->tag == TableType && type_eq(t, actual))
+            return Texts("TABLE_COPY(", compile_to_type(env, ast, t), ")");
     }
     return compile_to_type(env, ast, t);
 }
diff --git a/src/compile/promotions.c b/src/compile/promotions.c
index d453b764..68b4f64c 100644
--- a/src/compile/promotions.c
+++ b/src/compile/promotions.c
@@ -25,6 +25,21 @@ bool promote(env_t *env, ast_t *ast, Text_t *code, type_t *actual, type_t *neede
     type_t *more_complete = most_complete_type(actual, needed);
     if (more_complete) return true;
 
+    // Serialization/deserialization:
+    if (type_eq(needed, Type(ListType, Type(ByteType)))) {
+        *code = Texts("generic_serialize((", compile_declaration(actual, Text("[1]")), "){", *code, "}, ",
+                      compile_type_info(actual), ")");
+        return true;
+    } else if (type_eq(actual, Type(ListType, Type(ByteType)))) {
+        *code = Texts("({ ", compile_declaration(needed, Text("deserialized")),
+                      ";\n"
+                      "generic_deserialize(",
+                      *code, ", &deserialized, ", compile_type_info(needed),
+                      ");\n"
+                      "deserialized; })");
+        return true;
+    }
+
     // Optional promotion:
     if (needed->tag == OptionalType && type_eq(actual, Match(needed, OptionalType)->type)) {
         *code = promote_to_optional(actual, *code);
-- 
cgit v1.2.3