From 9c3cae740664a5043bacfa0b82eace8ed8239bee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EC=A0=95=EC=8B=9C=EC=9B=90?= <sebastianrcnt@yonsei.ac.kr>
Date: Sun, 16 Aug 2026 21:16:14 +0900
Subject: [PATCH] add M7 semantic foundation

---
 fec/src/m7.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 fec/src/m7.h

diff --git a/fec/src/m7.h b/fec/src/m7.h
new file mode 100644
index 0000000..ad0f968
--- /dev/null
+++ b/fec/src/m7.h
@@ -0,0 +1,31 @@
+#ifndef FE_M7_H
+#define FE_M7_H
+
+#include "types.h"
+
+typedef enum FeM7ContextKind {
+    FE_M7_CONTEXT_NONE = 0,
+    FE_M7_CONTEXT_SUCCESS,
+    FE_M7_CONTEXT_FAILURE
+} FeM7ContextKind;
+
+typedef enum FeM7LazyKind {
+    FE_M7_LAZY_NONE = 0,
+    FE_M7_LAZY_ORELSE,
+    FE_M7_LAZY_CATCH
+} FeM7LazyKind;
+
+FeType *fe_m7_optional_type(FeTypeCtx *ctx, FeType *payload);
+int fe_m7_optional_uses_niche(const FeType *payload);
+int fe_m7_can_contextual_null(const FeType *expected);
+
+FeType *fe_m7_error_union_type(FeTypeCtx *ctx, FeType *error_type,
+                               FeType *value_type);
+FeType *fe_m7_error_type(FeTypeCtx *ctx, const FeType *error_union);
+FeM7ContextKind fe_m7_error_context(FeTypeCtx *ctx, const FeType *expected,
+                                    const FeType *actual);
+
+FeM7LazyKind fe_m7_lazy_kind(const FeNode *node);
+int fe_m7_is_try(const FeNode *node);
+
+#endif