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-rw-r--r--README.md41
1 files changed, 37 insertions, 4 deletions
diff --git a/README.md b/README.md
index 1b58b91..425f706 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,8 @@ However it is rare to use this repository directly.
Once you've loaded fengari, you can use the JS API:
-```javascript
+```js
+const luaconf = fengari.luaconf;
const lua = fengari.lua;
const lauxlib = fengari.lauxlib;
const lualib = fengari.lualib;
@@ -45,16 +46,21 @@ Fengari implements Lua 5.3 semantics and will hopefully follow future Lua releas
Lua strings are 8-bits clean and can embed `\0`. Which means that invalid UTF-8/16 strings are valid Lua strings. Lua functions like `string.dump` even use strings as a way of storing binary data.
-To address that issue, Fengari uses [`Uint8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array) objects containing the raw bytes to implement lua strings. To push a JS string on the stack you can use `lua_pushliteral` which will convert it to an array of bytes before pushing it. To get a Lua string on the stack as a JS string you can use `lua_tojsstring` which will attempt to convert it to a UTF-16 JS string. The latter won't give you what you expect if the Lua string is not a valid UTF-16 sequence. You can also convert strings with `lua.to_luastring`, `lua.to_jsstring` and `lua.to_uristring`.
+To address that issue, Fengari uses [`Uint8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array) objects containing the raw bytes to implement lua strings. To push a JS string on the stack you can use `lua_pushliteral` which will convert it to an array of bytes before pushing it. To get a Lua string on the stack as a JS string you can use `lua_tojsstring` which will attempt to convert it to a UTF-16 JS string. The latter won't give you what you expect if the Lua string is not a valid UTF-16 sequence. You can also convert strings with `luastring_of`, `to_luastring`, `to_jsstring` and `to_uristring`.
+
### Integers
The JS number type is always a double, and hence cannot accurately represent integers with more than 53 bits. As such, we've taken the route of a rarely used define (`LUA_INT_TYPE=LUA_INT_LONG`) in the PUC-Rio sources, where floats are doubles, but integers are 32 bits.
+
### `require` and `package.loadlib`
In the browser `require` and `package.loadlib` try to find a file by making synchronous XHR requests.
+`require` has been extended to allow searchers to yield.
+
+
### _Missing_ features
- `lua_gc`/`collectgarbage`: Fengari relies on the JS garbage collector and does not implement its own.
@@ -66,11 +72,21 @@ In the browser `require` and `package.loadlib` try to find a file by making sync
- `os.execute`
- `debug.debug()` doesn't work from web workers due to lack of a method to get synchronous user input
- [Weak tables](http://www.lua.org/manual/5.3/manual.html#2.5.2)
+- `__gc` metamethods
-### _Differences_ from C API
+### _Differences_
+- `package.jspath` instead of `package.cpath`
+- `LUA_JSPATH_DEFAULT` instead of `LUA_CPATH_DEFAULT` (and contains .js extensions rather than .so or .dll extensions)
- `lua_tointegerx` and `lua_tonumberx` do not have out-parameters indicating conversion success. Instead, ``false`` is returned when conversion fails.
+- `luaL_execresult` takes an extra argument: an error object. The error object should have a fields `status`, `signal` and `errno`.
+- `luaL_fileresult` takes an extra argument: an error object. The error object should have a field `errno`.
+
+
+### Configuring
+
+Some luaconf options can be chosen at library load time. Fengari looks for `process.env.FENGARICONF` and if it exists, parses it as a JSON string.
## Extensions
@@ -115,9 +131,25 @@ var p = lua_toproxy(L, 1);
p(L);
````
+
+### `fengari` library
+
+A library containing metadata about the fengari release.
+
+ - `AUTHORS`
+ - `COPYRIGHT`
+ - `RELEASE`
+ - `VERSION`
+ - `VERSION_MAJOR`
+ - `VERSION_MINOR`
+ - `VERSION_NUM`
+ - `VERSION_RELEASE`
+
+This library is automatically loaded by `luaL_openlibs` into the global `"fengari"`.
+
+
## NYI
-- `math.randomseed()`
- `io.input()`: partially implemented
- `io.lines()`
- `io.open()`
@@ -130,6 +162,7 @@ p(L);
- `file:setvbuf()`
- `file:__gc()`
+
## References
- [Source code for Lua 5.3](lua.org/source/5.3/)