From 993aca2c5f62b3c839c133f96b07f8f26e4451c7 Mon Sep 17 00:00:00 2001
From: Teoxoy <28601907+Teoxoy@users.noreply.github.com>
Date: Fri, 22 Nov 2019 20:41:18 +0100
Subject: [PATCH] change API to allow for parsing code once then executing
 multiple times

---
 README.md     | 12 +++++++-----
 package.json  |  2 +-
 src/index.ts  | 32 +++++++++++++++++++++-----------
 tests/test.js |  8 ++++----
 4 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/README.md b/README.md
index 02ada4a..e542184 100644
--- a/README.md
+++ b/README.md
@@ -44,17 +44,19 @@ const luaEnv = luainjs.createEnv({
 })
 ```
 
-### Run a script or file
+### Execute a script or file
 
 ```js
-luaEnv.run('print(\'Hello world!\')')
+const luaScript = luaEnv.parse('print(\'Hello world!\')')
+const returnValue = luaScript.exec()
 ```
 
 ```js
-luaEnv.runfile('somefile.lua')
+const luaScript = luaEnv.parseFile('somefile.lua')
+const returnValue = luaScript.exec()
 ```
 
-`runfile` uses `config.fileExists` and `config.loadFile`
+`parseFile` uses `config.fileExists` and `config.loadFile`
 
 ### Create a global library
 
@@ -69,7 +71,7 @@ function helloBuilder(name) {
 const myLib = new luainjs.Table({ helloBuilder })
 luaEnv.loadLib('myLib', myLib)
 
-const helloStr = luaEnv.run(`return myLib.helloBuilder('John')`)
+const helloStr = luaEnv.parse(`return myLib.helloBuilder('John')`).exec()
 console.log(helloStr)
 ```
 
diff --git a/package.json b/package.json
index edc82d9..43303ca 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "lua-in-js",
-    "version": "2.1.1",
+    "version": "2.2.0",
     "description": "A Lua to JS transpiler/runtime",
     "keywords": [
         "lua",
diff --git a/src/index.ts b/src/index.ts
index 324b138..7e4fccf 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -11,7 +11,11 @@ import { libString, metatable as stringMetatable } from './lib/string'
 import { getLibOS } from './lib/os'
 import { getLibPackage } from './lib/package'
 import { LuaType, ensureArray, Config } from './utils'
-import { parse } from './parser'
+import { parse as parseScript } from './parser'
+
+interface Script {
+    exec: () => LuaType
+}
 
 const call = (f: Function | Table, ...args: LuaType[]): LuaType[] => {
     if (f instanceof Function) return ensureArray(f(...args))
@@ -49,8 +53,8 @@ const execChunk = (_G: Table, chunk: string, chunkName?: string): LuaType[] => {
 function createEnv(
     config: Config = {}
 ): {
-    run: (script: string) => LuaType
-    runfile: (path: string) => LuaType
+    parse: (script: string) => Script
+    parseFile: (path: string) => Script
     loadLib: (name: string, value: Table) => void
 } {
     const cfg: Config = {
@@ -63,7 +67,7 @@ function createEnv(
     const _G = createG(cfg, execChunk)
 
     const { libPackage, _require } = getLibPackage(
-        (content, moduleName) => execChunk(_G, parse(content), moduleName)[0],
+        (content, moduleName) => execChunk(_G, parseScript(content), moduleName)[0],
         cfg
     )
     const loaded = libPackage.get('loaded') as Table
@@ -82,19 +86,25 @@ function createEnv(
 
     _G.rawset('require', _require)
 
-    const run = (script: string): LuaType => execChunk(_G, parse(script))[0]
-    const runfile = (filename: string): LuaType => {
-        if (!cfg.fileExists) throw new LuaError('runfile requires the config.fileExists function')
-        if (!cfg.loadFile) throw new LuaError('runfile requires the config.loadFile function')
+    const parse = (code: string): Script => {
+        const script = parseScript(code)
+        return {
+            exec: () => execChunk(_G, script)[0]
+        }
+    }
+
+    const parseFile = (filename: string): Script => {
+        if (!cfg.fileExists) throw new LuaError('parseFile requires the config.fileExists function')
+        if (!cfg.loadFile) throw new LuaError('parseFile requires the config.loadFile function')
 
         if (!cfg.fileExists(filename)) throw new LuaError('file not found')
 
-        return run(cfg.loadFile(filename))
+        return parse(cfg.loadFile(filename))
     }
 
     return {
-        run,
-        runfile,
+        parse,
+        parseFile,
         loadLib
     }
 }
diff --git a/tests/test.js b/tests/test.js
index 3782604..062c99d 100644
--- a/tests/test.js
+++ b/tests/test.js
@@ -11,7 +11,7 @@ let exitCode = 0
         loadFile: p => fs.readFileSync(path.join(rootPath, p), { encoding: 'utf8' }),
         osExit: code => (exitCode += code)
     })
-    luaEnv.runfile('test-runner.lua')
+    luaEnv.parseFile('test-runner.lua').exec()
 }
 
 // TODO: make more official lua 5.3 tests pass (most of them don't pass because they `require "debug"`)
@@ -22,8 +22,8 @@ let exitCode = 0
         loadFile: p => fs.readFileSync(path.join(rootPath, p), { encoding: 'utf8' }),
         osExit: code => process.exit(code)
     })
-    luaEnv.runfile('goto.lua')
-    luaEnv.runfile('bwcoercion.lua')
+    luaEnv.parseFile('goto.lua').exec()
+    luaEnv.parseFile('bwcoercion.lua').exec()
 }
 
 {
@@ -34,7 +34,7 @@ let exitCode = 0
     }
     const myLib = new luainjs.Table({ helloBuilder })
     luaEnv.loadLib('myLib', myLib)
-    const str = luaEnv.run(`return myLib.helloBuilder('John')`)
+    const str = luaEnv.parse(`return myLib.helloBuilder('John')`).exec()
     if (str !== 'Hello John!') {
         throw Error("Strings don't match!")
     }