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author | kyren <kerriganw@gmail.com> | 2017-12-04 01:04:12 -0500 |
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committer | kyren <kerriganw@gmail.com> | 2017-12-04 01:04:12 -0500 |
commit | 0c644e71369893d49f8d3e0214dcbe3774207bcf (patch) | |
tree | baddda6a8a0f170348cdfb45f300fc2cabb2d5b7 /src/value.rs | |
parent | a44b6b5170829599dd1e12ec5dc21923cf2f078b (diff) | |
download | mlua-0c644e71369893d49f8d3e0214dcbe3774207bcf.zip |
more reorganization in an attempt to shrink the size of lua.rs
Diffstat (limited to 'src/value.rs')
-rw-r--r-- | src/value.rs | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/value.rs b/src/value.rs new file mode 100644 index 0000000..b3b4f2f --- /dev/null +++ b/src/value.rs @@ -0,0 +1,138 @@ +use std::str; +use std::ops::{Deref, DerefMut}; +use std::iter::FromIterator; +use std::collections::VecDeque; + +use error::*; +use types::{Integer, LightUserData, Number}; +use string::String; +use table::Table; +use function::Function; +use thread::Thread; +use userdata::AnyUserData; +use lua::Lua; + +/// A dynamically typed Lua value. +#[derive(Debug, Clone)] +pub enum Value<'lua> { + /// The Lua value `nil`. + Nil, + /// The Lua value `true` or `false`. + Boolean(bool), + /// A "light userdata" object, equivalent to a raw pointer. + LightUserData(LightUserData), + /// An integer number. + /// + /// Any Lua number convertible to a `Integer` will be represented as this variant. + Integer(Integer), + /// A floating point number. + Number(Number), + /// An interned string, managed by Lua. + /// + /// Unlike Rust strings, Lua strings may not be valid UTF-8. + String(String<'lua>), + /// Reference to a Lua table. + Table(Table<'lua>), + /// Reference to a Lua function (or closure). + Function(Function<'lua>), + /// Reference to a Lua thread (or coroutine). + Thread(Thread<'lua>), + /// Reference to a userdata object that holds a custom type which implements `UserData`. + /// Special builtin userdata types will be represented as other `Value` variants. + UserData(AnyUserData<'lua>), + /// `Error` is a special builtin userdata type. When received from Lua it is implicitly cloned. + Error(Error), +} +pub use self::Value::Nil; + +impl<'lua> Value<'lua> { + pub(crate) fn type_name(&self) -> &'static str { + match *self { + Value::Nil => "nil", + Value::Boolean(_) => "boolean", + Value::LightUserData(_) => "light userdata", + Value::Integer(_) => "integer", + Value::Number(_) => "number", + Value::String(_) => "string", + Value::Table(_) => "table", + Value::Function(_) => "function", + Value::Thread(_) => "thread", + Value::UserData(_) | Value::Error(_) => "userdata", + } + } +} + +/// Trait for types convertible to `Value`. +pub trait ToLua<'lua> { + /// Performs the conversion. + fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>>; +} + +/// Trait for types convertible from `Value`. +pub trait FromLua<'lua>: Sized { + /// Performs the conversion. + fn from_lua(lua_value: Value<'lua>, lua: &'lua Lua) -> Result<Self>; +} + +/// Multiple Lua values used for both argument passing and also for multiple return values. +#[derive(Debug, Clone)] +pub struct MultiValue<'lua>(VecDeque<Value<'lua>>); + +impl<'lua> MultiValue<'lua> { + /// Creates an empty `MultiValue` containing no values. + pub fn new() -> MultiValue<'lua> { + MultiValue(VecDeque::new()) + } +} + +impl<'lua> FromIterator<Value<'lua>> for MultiValue<'lua> { + fn from_iter<I: IntoIterator<Item = Value<'lua>>>(iter: I) -> Self { + MultiValue(VecDeque::from_iter(iter)) + } +} + +impl<'lua> IntoIterator for MultiValue<'lua> { + type Item = Value<'lua>; + type IntoIter = <VecDeque<Value<'lua>> as IntoIterator>::IntoIter; + + fn into_iter(self) -> Self::IntoIter { + self.0.into_iter() + } +} + +impl<'lua> Deref for MultiValue<'lua> { + type Target = VecDeque<Value<'lua>>; + + fn deref(&self) -> &Self::Target { + &self.0 + } +} + +impl<'lua> DerefMut for MultiValue<'lua> { + fn deref_mut(&mut self) -> &mut Self::Target { + &mut self.0 + } +} + +/// Trait for types convertible to any number of Lua values. +/// +/// This is a generalization of `ToLua`, allowing any number of resulting Lua values instead of just +/// one. Any type that implements `ToLua` will automatically implement this trait. +pub trait ToLuaMulti<'lua> { + /// Performs the conversion. + fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>>; +} + +/// Trait for types that can be created from an arbitrary number of Lua values. +/// +/// This is a generalization of `FromLua`, allowing an arbitrary number of Lua values to participate +/// in the conversion. Any type that implements `FromLua` will automatically implement this trait. +pub trait FromLuaMulti<'lua>: Sized { + /// Performs the conversion. + /// + /// In case `values` contains more values than needed to perform the conversion, the excess + /// values should be ignored. This reflects the semantics of Lua when calling a function or + /// assigning values. Similarly, if not enough values are given, conversions should assume that + /// any missing values are nil. + fn from_lua_multi(values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self>; +} |