Improved the internals of the LuaDeviceConfig macro and improve the

usability of the macro

Cargo.lock

@@ -110,6 +110,7 @@ dependencies = [
 name = "automation_macro"
 version = "0.1.0"
 dependencies = [
+ "itertools 0.12.1",
  "proc-macro2",
  "quote",
  "syn 2.0.60",

automation_macro/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 proc-macro = true
 
 [dependencies]
+itertools = "0.12.1"
 proc-macro2 = "1.0.81"
 quote = "1.0.36"
-syn = { version = "2.0.60", features = ["extra-traits"] }
+syn = { version = "2.0.60", features = ["extra-traits", "full"] }

automation_macro/src/lib.rs

@@ -1,7 +1,11 @@
+use itertools::Itertools;
 use proc_macro2::TokenStream;
-use quote::quote;
+use quote::{quote, quote_spanned};
+use syn::parse::{Parse, ParseStream};
 use syn::punctuated::Punctuated;
-use syn::{parse_macro_input, DeriveInput, Token};
+use syn::spanned::Spanned;
+use syn::token::Paren;
+use syn::{parenthesized, parse_macro_input, DeriveInput, Expr, LitStr, Result, Token};
 
 #[proc_macro_derive(LuaDevice, attributes(config))]
 pub fn lua_device_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
@@ -53,129 +57,110 @@ fn impl_lua_device_macro(ast: &syn::DeriveInput) -> TokenStream {
     gen
 }
 
-#[derive(Debug)]
+mod kw {
-enum Arg {
+    syn::custom_keyword!(device_config);
-    Flatten,
+    syn::custom_keyword!(flatten);
-    UserData,
+    syn::custom_keyword!(from_lua);
-    Rename(String),
+    syn::custom_keyword!(rename);
-    With(TokenStream),
+    syn::custom_keyword!(with);
-    Default(Option<syn::Ident>),
+    syn::custom_keyword!(from);
-}
+    syn::custom_keyword!(default);
-
-impl syn::parse::Parse for Arg {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-        let arg = match input.parse::<syn::Ident>()?.to_string().as_str() {
-            "flatten" => Arg::Flatten,
-            "user_data" => Arg::UserData,
-            "rename" => {
-                input.parse::<Token![=]>()?;
-                let lit = input.parse::<syn::Lit>()?;
-                if let syn::Lit::Str(lit_str) = lit {
-                    Arg::Rename(lit_str.value())
-                } else {
-                    panic!("Expected literal string");
-                }
-            }
-            "with" => {
-                input.parse::<Token![=]>()?;
-                let lit = input.parse::<syn::Lit>()?;
-                if let syn::Lit::Str(lit_str) = lit {
-                    let token_stream: TokenStream = lit_str.parse()?;
-                    Arg::With(token_stream)
-                } else {
-                    panic!("Expected literal string");
-                }
-            }
-            "default" => {
-                if input.parse::<Token![=]>().is_ok() {
-                    let func = input.parse::<syn::Ident>()?;
-                    Arg::Default(Some(func))
-                } else {
-                    Arg::Default(None)
-                }
-            }
-            name => todo!("Handle unknown arg: {name}"),
-        };
-
-        Ok(arg)
-    }
 }
 
 #[derive(Debug)]
-struct ArgsParser {
+enum Argument {
-    args: Punctuated<Arg, Token![,]>,
+    Flatten {
+        _keyword: kw::flatten,
+    },
+    FromLua {
+        _keyword: kw::from_lua,
+    },
+    Rename {
+        _keyword: kw::rename,
+        _paren: Paren,
+        ident: LitStr,
+    },
+    With {
+        _keyword: kw::with,
+        _paren: Paren,
+        // TODO: Ideally we capture this better
+        expr: Expr,
+    },
+    From {
+        _keyword: kw::from,
+        _paren: Paren,
+        ty: syn::Type,
+    },
+    Default {
+        _keyword: kw::default,
+    },
+    DefaultExpr {
+        _keyword: kw::default,
+        _paren: Paren,
+        expr: Expr,
+    },
 }
 
-impl syn::parse::Parse for ArgsParser {
+impl Parse for Argument {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
+    fn parse(input: ParseStream) -> Result<Self> {
-        let args = input.parse_terminated(Arg::parse, Token![,])?;
+        let lookahead = input.lookahead1();
-
+        if lookahead.peek(kw::flatten) {
-        Ok(Self { args })
+            Ok(Self::Flatten {
+                _keyword: input.parse()?,
+            })
+        } else if lookahead.peek(kw::from_lua) {
+            Ok(Self::FromLua {
+                _keyword: input.parse()?,
+            })
+        } else if lookahead.peek(kw::rename) {
+            let content;
+            Ok(Self::Rename {
+                _keyword: input.parse()?,
+                _paren: parenthesized!(content in input),
+                ident: content.parse()?,
+            })
+        } else if lookahead.peek(kw::with) {
+            let content;
+            Ok(Self::With {
+                _keyword: input.parse()?,
+                _paren: parenthesized!(content in input),
+                expr: content.parse()?,
+            })
+        } else if lookahead.peek(kw::from) {
+            let content;
+            Ok(Self::From {
+                _keyword: input.parse()?,
+                _paren: parenthesized!(content in input),
+                ty: content.parse()?,
+            })
+        } else if lookahead.peek(kw::default) {
+            let keyword = input.parse()?;
+            if input.peek(Paren) {
+                let content;
+                Ok(Self::DefaultExpr {
+                    _keyword: keyword,
+                    _paren: parenthesized!(content in input),
+                    expr: content.parse()?,
+                })
+            } else {
+                Ok(Self::Default { _keyword: keyword })
+            }
+        } else {
+            Err(lookahead.error())
+        }
     }
 }
 
 #[derive(Debug)]
 struct Args {
-    flatten: bool,
+    args: Punctuated<Argument, Token![,]>,
-    user_data: bool,
-    rename: Option<String>,
-    with: Option<TokenStream>,
-    default: Option<Option<syn::Ident>>,
 }
 
-impl Args {
+impl Parse for Args {
-    fn new(args: Vec<Arg>) -> Self {
+    fn parse(input: ParseStream) -> Result<Self> {
-        let mut result = Args {
+        Ok(Self {
-            flatten: false,
+            args: input.parse_terminated(Argument::parse, Token![,])?,
-            user_data: false,
+        })
-            rename: None,
-            with: None,
-            default: None,
-        };
-        for arg in args {
-            match arg {
-                Arg::Flatten => {
-                    if result.flatten {
-                        panic!("Option 'flatten' is already set")
-                    }
-                    result.flatten = true
-                }
-                Arg::UserData => {
-                    if result.flatten {
-                        panic!("Option 'user_data' is already set")
-                    }
-                    result.user_data = true
-                }
-                Arg::Rename(name) => {
-                    if result.rename.is_some() {
-                        panic!("Option 'rename' is already set")
-                    }
-                    result.rename = Some(name)
-                }
-                Arg::With(ty) => {
-                    if result.with.is_some() {
-                        panic!("Option 'with' is already set")
-                    }
-                    result.with = Some(ty)
-                }
-                Arg::Default(func) => {
-                    if result.default.is_some() {
-                        panic!("Option 'default' is already set")
-                    }
-                    result.default = Some(func)
-                }
-            }
-        }
-
-        if result.flatten && result.user_data {
-            panic!("The options 'flatten' and 'user_data' conflict with each other")
-        }
-
-        if result.flatten && result.default.is_some() {
-            panic!("The options 'flatten' and 'default' conflict with each other")
-        }
-
-        result
     }
 }
 
@@ -186,12 +171,8 @@ pub fn lua_device_config_derive(input: proc_macro::TokenStream) -> proc_macro::T
     impl_lua_device_config_macro(&ast).into()
 }
 
-// struct Args
-
 fn impl_lua_device_config_macro(ast: &syn::DeriveInput) -> TokenStream {
     let name = &ast.ident;
-    // TODO: Handle errors properly
-    // This includes making sure one, and only one config is specified
     let fields = if let syn::Data::Struct(syn::DataStruct {
         fields: syn::Fields::Named(syn::FieldsNamed { ref named, .. }),
         ..
@@ -199,72 +180,91 @@ fn impl_lua_device_config_macro(ast: &syn::DeriveInput) -> TokenStream {
     {
         named
     } else {
-        unimplemented!("Macro can only handle named structs");
+        return quote_spanned! {ast.span() => compile_error!("This macro only works on named structs")};
     };
 
+    let field_names: Vec<_> = fields
+        .iter()
+        .map(|field| field.ident.clone().unwrap())
+        .collect();
+
     let fields: Vec<_> = fields
 		.iter()
 		.map(|field| {
 			let field_name = field.ident.clone().unwrap();
-            let args: Vec<_> = field
+			let (args, errors): (Vec<_>, Vec<_>) = field
 				.attrs
 				.iter()
 				.filter_map(|attr| {
 					if attr.path().is_ident("device_config") {
-                        let args: ArgsParser = attr.parse_args().unwrap();
+						Some(attr.parse_args::<Args>().map(|args| args.args))
-                        Some(args.args)
 					} else {
 						None
 					}
 				})
-                .flatten()
+				.partition_result();
+
+			let errors: Vec<_> = errors
+				.iter()
+				.map(|error| error.to_compile_error())
 				.collect();
 
-            let args = Args::new(args);
+			if !errors.is_empty() {
-
+				return quote! { #(#errors)* };
-            let table_name = if let Some(name) = args.rename {
-                name
-            } else {
-                field_name.to_string()
-            };
-
-			// TODO: Improve how optional fields are detected
-			let optional = if let syn::Type::Path(path) = field.ty.clone() {
-				path.path.segments.first().unwrap().ident == "Option"
-			} else {
-				false
-			};
-
-            let default = if optional {
-				quote! { None }
-			} else if let Some(func) = args.default {
-				if func.is_some() {
-					quote! { #func() }
-				} else {
-					quote! { Default::default() }
 			}
-            } else {
+
+			let args: Vec<_> = args.into_iter().flatten().collect();
+
+			let table_name = match args
+				.iter()
+				.filter_map(|arg| match arg {
+					Argument::Rename { ident, .. } => Some(ident.value()),
+					_ => None,
+				})
+				.collect::<Vec<_>>()
+			.as_slice()
+			{
+				[] => field_name.to_string(),
+				[rename] => rename.to_owned(),
+				_ => return quote_spanned! {field.span() => compile_error!("Field contains duplicate 'rename'")},
+			};
+
+			// TODO: Detect Option<_> properly and use Default::default() as fallback automatically
 			let missing = format!("Missing field '{table_name}'");
-                quote! { panic!(#missing) }
+			let default = match args
+				.iter()
+				.filter_map(|arg| match arg {
+					Argument::Default { .. } => Some(quote! { Default::default() }),
+					Argument::DefaultExpr { expr, .. } => Some(quote! { (#expr) }),
+					_ => None,
+				})
+				.collect::<Vec<_>>()
+			.as_slice()
+			{
+				[] => quote! {panic!(#missing)},
+				[default] => default.to_owned(),
+				_ => return quote_spanned! {field.span() => compile_error!("Field contains duplicate 'default'")},
 			};
 
-			let value = if args.flatten {
+
-            	// println!("ValueFlatten: {}", field_name);
+			let value = match args
-            	quote! {
+				.iter()
+				.filter_map(|arg| match arg {
+					Argument::Flatten { .. } => Some(quote! {
 						mlua::LuaSerdeExt::from_value_with(lua, value.clone(), mlua::DeserializeOptions::new().deny_unsupported_types(false))?
-            	}
+					}),
-			} else if args.user_data {
+					Argument::FromLua { .. } => Some(quote! {
-            	// println!("UserData: {}", field_name);
-            	quote! {
 						if table.contains_key(#table_name)? {
 							table.get(#table_name)?
 						} else {
 							#default
 						}
-            	}
+					}),
-			} else {
+					_ => None,
-            	// println!("Value: {}", field_name);
+				})
-                quote! {
+				.collect::<Vec<_>>()
+			.as_slice() {
+				[] => quote! {
 					{
 						let #field_name: mlua::Value = table.get(#table_name)?;
 						if !#field_name.is_nil() {
@@ -273,33 +273,39 @@ fn impl_lua_device_config_macro(ast: &syn::DeriveInput) -> TokenStream {
 							#default
 						}
 					}
-                }
+				},
+				[value] => value.to_owned(),
+				_ => return quote_spanned! {field.span() => compile_error!("Only one of either 'flatten' or 'from_lua' is allowed")},
 			};
 
-			let value = if let Some(temp_type) = args.with {
+			let value = match args
-				if optional {
+				.iter()
-					quote! {
+				.filter_map(|arg| match arg {
+					Argument::From { ty, .. } => Some(quote! {
 						{
-							let temp: #temp_type = #value;
+							let temp: #ty = #value;
-							temp.map(|v| v.into())
-						}
-					}
-				} else {
-					quote! {
-						{
-							let temp: #temp_type = #value;
 							temp.into()
 						}
+					}),
+					Argument::With { expr, .. } => Some(quote! {
+						{
+							let temp = #value;
+							(#expr)(temp)
 						}
-				}
+					}),
-			} else {
+					_ => None,
-				value
+				})
+				.collect::<Vec<_>>()
+			.as_slice() {
+				[] => value,
+				[value] => value.to_owned(),
+				_ => return quote_spanned! {field.span() => compile_error!("Field contains duplicate 'as'")},
 			};
 
-			quote! {
+			quote! { #value }
-				#field_name: #value
-			}
 		})
+		.zip(field_names)
+		.map(|(value, name)| quote! { #name: #value })
 		.collect();
 
     let gen = quote! {

src/devices/air_filter.rs

@@ -22,7 +22,7 @@ pub struct AirFilterConfig {
     info: InfoConfig,
     #[device_config(flatten)]
     mqtt: MqttDeviceConfig,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     client: WrappedAsyncClient,
 }
 

src/devices/audio_setup.rs

@@ -15,9 +15,9 @@ use crate::messages::{RemoteAction, RemoteMessage};
 pub struct AudioSetupConfig {
     #[device_config(flatten)]
     mqtt: MqttDeviceConfig,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     mixer: WrappedDevice,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     speakers: WrappedDevice,
 }
 

src/devices/contact_sensor.rs

@@ -13,7 +13,6 @@ use crate::device_manager::{DeviceConfig, WrappedDevice};
 use crate::devices::{As, DEFAULT_PRESENCE};
 use crate::error::DeviceConfigError;
 use crate::event::{OnMqtt, OnPresence};
-use crate::helper::DurationSeconds;
 use crate::messages::{ContactMessage, PresenceMessage};
 use crate::mqtt::WrappedAsyncClient;
 use crate::traits::Timeout;
@@ -23,7 +22,7 @@ use crate::traits::Timeout;
 pub struct PresenceDeviceConfig {
     #[device_config(flatten)]
     pub mqtt: MqttDeviceConfig,
-    #[device_config(with = "DurationSeconds")]
+    #[device_config(with(Duration::from_secs))]
     pub timeout: Duration,
 }
 
@@ -44,9 +43,9 @@ impl From<TriggerDevicesHelper> for Vec<(WrappedDevice, bool)> {
 
 #[derive(Debug, Clone, LuaDeviceConfig)]
 pub struct TriggerConfig {
-    #[device_config(user_data, with = "TriggerDevicesHelper")]
+    #[device_config(from_lua, from(TriggerDevicesHelper))]
     devices: Vec<(WrappedDevice, bool)>,
-    #[device_config(with = "Option<DurationSeconds>")]
+    #[device_config(default, with(|t: Option<_>| t.map(Duration::from_secs)))]
     pub timeout: Option<Duration>,
 }
 
@@ -54,11 +53,11 @@ pub struct TriggerConfig {
 pub struct ContactSensorConfig {
     #[device_config(flatten)]
     mqtt: MqttDeviceConfig,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     presence: Option<PresenceDeviceConfig>,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     trigger: Option<TriggerConfig>,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     client: WrappedAsyncClient,
 }
 

src/devices/debug_bridge.rs

@@ -14,7 +14,7 @@ use crate::mqtt::WrappedAsyncClient;
 pub struct DebugBridgeConfig {
     #[device_config(flatten)]
     pub mqtt: MqttDeviceConfig,
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     client: WrappedAsyncClient,
 }
 

src/devices/hue_bridge.rs

@@ -9,7 +9,6 @@ use crate::device_manager::DeviceConfig;
 use crate::devices::Device;
 use crate::error::DeviceConfigError;
 use crate::event::{OnDarkness, OnPresence};
-use crate::helper::Ipv4SocketAddr;
 
 #[derive(Debug)]
 pub enum Flag {
@@ -25,7 +24,7 @@ pub struct FlagIDs {
 
 #[derive(Debug, LuaDeviceConfig, Clone)]
 pub struct HueBridgeConfig {
-    #[device_config(rename = "ip", with = "Ipv4SocketAddr<80>")]
+    #[device_config(rename("ip"), with(|ip| SocketAddr::new(ip, 80)))]
     pub addr: SocketAddr,
     pub login: String,
     pub flags: FlagIDs,

src/devices/hue_light.rs

@@ -14,13 +14,12 @@ use crate::config::MqttDeviceConfig;
 use crate::device_manager::DeviceConfig;
 use crate::error::DeviceConfigError;
 use crate::event::OnMqtt;
-use crate::helper::Ipv4SocketAddr;
 use crate::messages::{RemoteAction, RemoteMessage};
 use crate::traits::Timeout;
 
 #[derive(Debug, Clone, LuaDeviceConfig)]
 pub struct HueGroupConfig {
-    #[device_config(rename = "ip", with = "Ipv4SocketAddr<80>")]
+    #[device_config(rename("ip"), with(|ip| SocketAddr::new(ip, 80)))]
     pub addr: SocketAddr,
     pub login: String,
     pub group_id: isize,

src/devices/ikea_outlet.rs

@@ -17,7 +17,6 @@ use crate::device_manager::DeviceConfig;
 use crate::devices::Device;
 use crate::error::DeviceConfigError;
 use crate::event::{OnMqtt, OnPresence};
-use crate::helper::DurationSeconds;
 use crate::messages::{OnOffMessage, RemoteAction, RemoteMessage};
 use crate::mqtt::WrappedAsyncClient;
 use crate::traits::Timeout;
@@ -36,21 +35,17 @@ pub struct IkeaOutletConfig {
     info: InfoConfig,
     #[device_config(flatten)]
     mqtt: MqttDeviceConfig,
-    #[device_config(default = default_outlet_type)]
+    #[device_config(default(OutletType::Outlet))]
     outlet_type: OutletType,
-    #[device_config(with = "Option<DurationSeconds>")]
+    #[device_config(default, with(|t: Option<_>| t.map(Duration::from_secs)))]
     timeout: Option<Duration>,
     #[device_config(default)]
     pub remotes: Vec<MqttDeviceConfig>,
 
-    #[device_config(user_data)]
+    #[device_config(from_lua)]
     client: WrappedAsyncClient,
 }
 
-fn default_outlet_type() -> OutletType {
-    OutletType::Outlet
-}
-
 #[async_trait]
 impl DeviceConfig for IkeaOutletConfig {
     async fn create(&self, identifier: &str) -> Result<Box<dyn Device>, DeviceConfigError> {

src/devices/kasa_outlet.rs

@@ -15,11 +15,10 @@ use tracing::trace;
 use super::Device;
 use crate::device_manager::DeviceConfig;
 use crate::error::DeviceConfigError;
-use crate::helper::Ipv4SocketAddr;
 
 #[derive(Debug, Clone, LuaDeviceConfig)]
 pub struct KasaOutletConfig {
-    #[device_config(rename = "ip", with = "Ipv4SocketAddr<9999>")]
+    #[device_config(rename("ip"), with(|ip| SocketAddr::new(ip, 9999)))]
     addr: SocketAddr,
 }
 

src/devices/light_sensor.rs

@@ -7,8 +7,7 @@ use crate::config::MqttDeviceConfig;
 use crate::device_manager::DeviceConfig;
 use crate::devices::Device;
 use crate::error::DeviceConfigError;
-use crate::event::{self, Event, OnMqtt};
+use crate::event::{self, Event, EventChannel, OnMqtt};
-use crate::helper::TxHelper;
 use crate::messages::BrightnessMessage;
 
 #[derive(Debug, Clone, LuaDeviceConfig)]
@@ -17,7 +16,7 @@ pub struct LightSensorConfig {
     pub mqtt: MqttDeviceConfig,
     pub min: isize,
     pub max: isize,
-    #[device_config(rename = "event_channel", user_data, with = "TxHelper")]
+    #[device_config(rename("event_channel"), from_lua, with(|ec: EventChannel| ec.get_tx()))]
     pub tx: event::Sender,
 }
 

src/devices/wake_on_lan.rs

@@ -24,14 +24,10 @@ pub struct WakeOnLANConfig {
     #[device_config(flatten)]
     mqtt: MqttDeviceConfig,
     mac_address: MacAddress,
-    #[device_config(default = default_broadcast_ip)]
+    #[device_config(default(Ipv4Addr::new(255, 255, 255, 255)))]
     broadcast_ip: Ipv4Addr,
 }
 
-fn default_broadcast_ip() -> Ipv4Addr {
-    Ipv4Addr::new(255, 255, 255, 255)
-}
-
 #[async_trait]
 impl DeviceConfig for WakeOnLANConfig {
     async fn create(&self, identifier: &str) -> Result<Box<dyn Device>, DeviceConfigError> {

src/devices/washer.rs

@@ -8,8 +8,7 @@ use super::{Device, Notification};
 use crate::config::MqttDeviceConfig;
 use crate::device_manager::DeviceConfig;
 use crate::error::DeviceConfigError;
-use crate::event::{self, Event, OnMqtt};
+use crate::event::{self, Event, EventChannel, OnMqtt};
-use crate::helper::TxHelper;
 use crate::messages::PowerMessage;
 
 #[derive(Debug, Clone, LuaDeviceConfig)]
@@ -18,7 +17,7 @@ pub struct WasherConfig {
     mqtt: MqttDeviceConfig,
     // Power in Watt
     threshold: f32,
-    #[device_config(rename = "event_channel", user_data, with = "TxHelper")]
+    #[device_config(rename("event_channel"), from_lua, with(|ec: EventChannel| ec.get_tx()))]
     pub tx: event::Sender,
 }
 

src/helper.rs

@@ -1,40 +0,0 @@
-use std::net::{Ipv4Addr, SocketAddr};
-use std::time::Duration;
-
-use mlua::FromLua;
-use serde::Deserialize;
-
-use crate::event::{self, EventChannel};
-
-#[derive(Debug, Deserialize)]
-pub struct DurationSeconds(u64);
-
-impl From<DurationSeconds> for Duration {
-    fn from(value: DurationSeconds) -> Self {
-        Self::from_secs(value.0)
-    }
-}
-
-#[derive(Debug, Deserialize)]
-pub struct Ipv4SocketAddr<const PORT: u16>(Ipv4Addr);
-
-impl<const PORT: u16> From<Ipv4SocketAddr<PORT>> for SocketAddr {
-    fn from(ip: Ipv4SocketAddr<PORT>) -> Self {
-        Self::from((ip.0, PORT))
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct TxHelper(EventChannel);
-
-impl<'lua> FromLua<'lua> for TxHelper {
-    fn from_lua(value: mlua::Value<'lua>, lua: &'lua mlua::Lua) -> mlua::Result<Self> {
-        Ok(TxHelper(mlua::FromLua::from_lua(value, lua)?))
-    }
-}
-
-impl From<TxHelper> for event::Sender {
-    fn from(value: TxHelper) -> Self {
-        value.0.get_tx()
-    }
-}

src/lib.rs

@@ -7,7 +7,6 @@ pub mod device_manager;
 pub mod devices;
 pub mod error;
 pub mod event;
-pub mod helper;
 pub mod messages;
 pub mod mqtt;
 pub mod schedule;