1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64

use std::collections::HashMap;

use proc_macro_hack::proc_macro_hack;
use rlua::{Result, Context, UserData, UserDataMethods, MetaMethod, Value, Table, RegistryKey};

#[proc_macro_hack]
pub use include_lua_macro::include_lua;

pub struct LuaModules {
    files: HashMap<String, (String, String)>,
    prefix: String,
}

impl LuaModules {
    #[doc(hidden)] // This is not a public API!
    pub fn __new(files: HashMap<String, (String, String)>, prefix: &str) -> LuaModules {
        LuaModules { files: files, prefix: prefix.to_string() }
    }
}

pub struct Searcher(LuaModules, RegistryKey);

impl UserData for Searcher {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
        methods.add_meta_method(MetaMethod::Call, |ctx, this, value: String| {
            Ok(match this.0.files.get(&value) {
                Some((source, path)) => {
                    Value::Function(ctx.load(source)
                        .set_name(&format!("{}\\{} (virtual)", &this.0.prefix, path))?
                        .set_environment(ctx.registry_value::<Table>(&this.1)?)?
                        .into_function()?
                    )
                }
                None => Value::Nil,
            })
        });
    }
}

pub trait ContextExt<'a> {
    fn add_modules(&self, modules: LuaModules) -> Result<()>;
    fn add_modules_with_env(&self, modules: LuaModules, environment: Table<'a>) -> Result<()>;
    fn make_searcher(&self, modules: LuaModules) -> Result<Searcher>;
    fn make_searcher_with_env(&self, modules: LuaModules, environment: Table<'a>) -> Result<Searcher>;
}

impl<'a> ContextExt<'a> for Context<'a> {
    fn add_modules(&self, modules: LuaModules) -> Result<()> {
        self.add_modules_with_env(modules, self.globals())
    }

    fn add_modules_with_env(&self, modules: LuaModules, environment: Table<'a>) -> Result<()> {
        let searchers: Table = self.globals().get::<_, Table>("package")?.get("searchers")?;
        searchers.set(searchers.len()? + 1, self.make_searcher_with_env(modules, environment)?)
    }

    fn make_searcher(&self, modules: LuaModules) -> Result<Searcher> {
        self.make_searcher_with_env(modules, self.globals())
    }

    fn make_searcher_with_env(&self, modules: LuaModules, environment: Table<'a>) -> Result<Searcher> {
        Ok(Searcher(modules, self.create_registry_value(environment)?))
    }
}