feat: add ScriptValue::Map and create appropriate conversions in lua and rhai (#229)

feat: add hashmap support

Author: makspll

crates/languages/bevy_mod_scripting_lua/src/bindings/script_value.rs

@@ -38,7 +38,7 @@ impl From<LuaScriptValue> for ScriptValue {
 }
 
 impl FromLua for LuaScriptValue {
-    fn from_lua(value: mlua::Value, _lua: &mlua::Lua) -> mlua::Result<Self> {
+    fn from_lua(value: mlua::Value, lua: &mlua::Lua) -> mlua::Result<Self> {
         Ok(match value {
             Value::Nil => ScriptValue::Unit,
             Value::Boolean(b) => ScriptValue::Bool(b),
@@ -50,12 +50,34 @@ impl FromLua for LuaScriptValue {
             Value::Number(n) => ScriptValue::Float(n),
             Value::String(s) => ScriptValue::String(s.to_str()?.to_owned().into()),
             Value::Table(table) => {
-                let mut vec = Vec::with_capacity(table.len()? as usize);
-                for i in table.sequence_values() {
-                    let v: LuaScriptValue = i?;
-                    vec.push(v.into());
+                // check the key types, if strings then it's a map
+                let mut iter = table.pairs::<Value, LuaScriptValue>();
+
+                match iter.next() {
+                    Some(v) => {
+                        let (k, v) = v?;
+                        // if the key is a string, then it's a map
+                        if k.is_string() {
+                            let mut map = HashMap::new();
+                            map.insert(k.to_string()?, v.into());
+                            for pair in iter {
+                                let (k, v) = pair?;
+                                let str_: String = String::from_lua(k, lua)?;
+                                map.insert(str_, v.into());
+                            }
+                            return Ok(LuaScriptValue::from(ScriptValue::Map(map)));
+                        } else {
+                            // if the key is an integer, then it's a list
+                            let mut vec = Vec::with_capacity(table.len()? as usize);
+                            vec.push(v.into());
+                            for pair in iter {
+                                vec.push(pair?.1.into());
+                            }
+                            return Ok(LuaScriptValue::from(ScriptValue::List(vec)));
+                        }
+                    }
+                    None => return Ok(LuaScriptValue::from(ScriptValue::List(vec![]))),
                 }
-                ScriptValue::List(vec)
             }
             // Value::Thread(thread) => todo!(),
             Value::UserData(ud) => {

crates/languages/bevy_mod_scripting_lua/tests/data/hashmap/can_pass_and_return_hashmap.lua

@@ -0,0 +1,7 @@
+local map = make_hashmap({
+    key1 = 2,
+    key2 = 3,
+})
+
+assert(map["key1"] == 2, "map[\"key1\"] should be 2")
+assert(map["key2"] == 3, "map[\"key2\"] should be 3")

crates/languages/bevy_mod_scripting_rhai/src/bindings/script_value.rs

@@ -129,7 +129,7 @@ pub trait FromDynamic: Sized {
     fn from_dynamic(dynamic: Dynamic) -> Result<Self, Box<EvalAltResult>>;
 }
 
-#[allow(clippy::unwrap_used, clippy::todo)]
+#[allow(clippy::unwrap_used)]
 impl FromDynamic for ScriptValue {
     fn from_dynamic(dynamic: Dynamic) -> Result<Self, Box<EvalAltResult>> {
         match dynamic {
@@ -140,6 +140,18 @@ impl FromDynamic for ScriptValue {
             d if d.is_string() => Ok(ScriptValue::String(
                 d.into_immutable_string().unwrap().to_string().into(),
             )),
+            mut d if d.is_map() => Ok(ScriptValue::Map(
+                d.as_map_mut()
+                    .map_err(|_| {
+                        Box::new(EvalAltResult::ErrorSystem(
+                            "FromDynamic".to_string(),
+                            InteropError::invariant("d is proved to be a map").into(),
+                        ))
+                    })?
+                    .iter()
+                    .map(|(k, v)| Ok((k.to_string(), ScriptValue::from_dynamic(v.clone())?)))
+                    .collect::<Result<_, Box<EvalAltResult>>>()?,
+            )),
             d if d.is_array() => Ok(ScriptValue::List(
                 d.into_array()
                     .map_err(|_| InteropError::invariant("d is proved to be an array"))?
@@ -151,7 +163,13 @@ impl FromDynamic for ScriptValue {
                 if let Some(v) = d.try_cast::<RhaiReflectReference>() {
                     Ok(ScriptValue::Reference(v.0))
                 } else {
-                    todo!("from conversion not implemented yet")
+                    Err(Box::new(EvalAltResult::ErrorSystem(
+                        "FromDynamic".to_string(),
+                        Box::new(InteropError::impossible_conversion(std::any::TypeId::of::<
+                            ScriptValue,
+                        >(
+                        ))),
+                    )))
                 }
             }
         }

crates/languages/bevy_mod_scripting_rhai/tests/data/hashmap/can_pass_and_return_hashmap.rhai

@@ -0,0 +1,7 @@
+let my_map = make_hashmap.call(#{
+    key1: 2,
+    key2: 3,
+});
+
+assert(my_map["key1"] == 2, "map[\"key1\"] should be 2");
+assert(my_map["key2"] == 3, "map[\"key2\"] should be 3");

crates/script_integration_test_harness/src/test_functions.rs

@@ -1,4 +1,4 @@
-use std::sync::Arc;
+use std::{collections::HashMap, sync::Arc};
 
 use bevy::{
     app::App,
@@ -102,5 +102,6 @@ pub fn register_test_functions(world: &mut App) {
         );
 
     NamespaceBuilder::<GlobalNamespace>::new_unregistered(world)
-        .register("global_hello_world", || Ok("hi!"));
+        .register("global_hello_world", || Ok("hi!"))
+        .register("make_hashmap", |map: HashMap<String, usize>| map);
 }