From ed51ebc916a0806f4c78513ec947bc0b2db8219e Mon Sep 17 00:00:00 2001
From: Xie Yuheng <xyheme@gmail.com>
Date: Mon, 1 Apr 2024 07:54:58 +0800
Subject: [PATCH] =?UTF-8?q?[lang1]=20=E6=94=AF=E6=8C=81=20`(import)`?=
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---
 TODO.md                     |  1 -
 src/lang1/mod/index.ts      |  1 +
 src/lang1/mod/modResolve.ts |  5 +++++
 src/lang1/run/execute.ts    |  7 ++++++-
 src/lang1/run/importOne.ts  | 29 +++++++++++++++++++++++++++++
 5 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 src/lang1/mod/modResolve.ts
 create mode 100644 src/lang1/run/importOne.ts

diff --git a/TODO.md b/TODO.md
index 205a765..e7d048f 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,4 +1,3 @@
-[lang1] 支持 `(import)`
 [lang1] test `(import)`
 
 > [lang0] 支持直接递归函数与相互递归函数，不能判断等价的地方就不判断。
diff --git a/src/lang1/mod/index.ts b/src/lang1/mod/index.ts
index bb33960..30cdcc6 100644
--- a/src/lang1/mod/index.ts
+++ b/src/lang1/mod/index.ts
@@ -1,4 +1,5 @@
 export * from "./Mod.js"
+export * from "./modResolve.js"
 export * from "./createMod.js"
 export * from "./modDefine.js"
 export * from "./modFind.js"
diff --git a/src/lang1/mod/modResolve.ts b/src/lang1/mod/modResolve.ts
new file mode 100644
index 0000000..5288b72
--- /dev/null
+++ b/src/lang1/mod/modResolve.ts
@@ -0,0 +1,5 @@
+import { type Mod } from "./index.js"
+
+export function modResolve(mod: Mod, href: string): URL {
+  return new URL(href, mod.url)
+}
diff --git a/src/lang1/run/execute.ts b/src/lang1/run/execute.ts
index 518620e..ab01d9f 100644
--- a/src/lang1/run/execute.ts
+++ b/src/lang1/run/execute.ts
@@ -2,6 +2,7 @@ import { formatExp } from "../format/formatExp.js"
 import { modDefine, type Mod } from "../mod/index.js"
 import { reduce } from "../reduce/reduce.js"
 import { type Stmt } from "../stmt/Stmt.js"
+import { importOne } from "./importOne.js"
 
 export function execute(mod: Mod, stmt: Stmt): null | string {
   switch (stmt["@kind"]) {
@@ -20,7 +21,11 @@ export function execute(mod: Mod, stmt: Stmt): null | string {
     }
 
     case "Import": {
-      throw new Error("TODO")
+      for (const entry of stmt.entries) {
+        importOne(mod, stmt.path, entry)
+      }
+
+      return null
     }
   }
 }
diff --git a/src/lang1/run/importOne.ts b/src/lang1/run/importOne.ts
new file mode 100644
index 0000000..c1f036c
--- /dev/null
+++ b/src/lang1/run/importOne.ts
@@ -0,0 +1,29 @@
+import { modDefine, modFind, modResolve } from "../mod/index.js"
+import type { Mod } from "../mod/Mod.js"
+import type { ImportEntry } from "../stmt/Stmt.js"
+import { executeMod } from "./executeMod.js"
+
+export function importOne(mod: Mod, path: string, entry: ImportEntry): void {
+  const url = modResolve(mod, path)
+  if (url.href === mod.url.href) {
+    throw new Error(`I can not circular import: ${path}`)
+  }
+
+  const found = mod.loadedMods.get(url.href)
+  if (found === undefined) {
+    throw new Error(`Mod is not loaded: ${path}`)
+  }
+
+  executeMod(found.mod)
+
+  const { name, rename } = entry
+
+  const def = modFind(found.mod, name)
+  if (def === undefined) {
+    throw new Error(
+      `I can not import undefined name: ${name}, from path: ${path}`,
+    )
+  }
+
+  modDefine(mod, rename || name, def)
+}