Add custom attributes for States and Events enum

CHANGELOG.md

@@ -7,7 +7,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
-* None yet!
+### Added
+
+- Add support for defining States and Events attributes using `states_attr` and `events_attr` fields
+
+### Changed
+
+- [breaking] Remove `derive_states` and `derive_events` fields in lieu of `states_attr` and `events_attr` to define attributes generically
 
 ## [v0.8.0] - 2024-08-07
 

Cargo.toml

@@ -16,6 +16,7 @@ smlang-macros = { path = "macros", version = "0.8.0" }
 [dev-dependencies]
 smol = "1"
 derive_more = "0.99.17"
+serde = {version = "1",features = ["derive"]}
 
 [target.'cfg(not(target_os = "none"))'.dev-dependencies]
 trybuild = "1.0"

README.md

@@ -370,18 +370,18 @@ in `dominos`.
 
 ## Helpers
 
-### Auto-derive certain traits for states and events
+### Specify attributes for states and events
 
-Setting `derive_events` and `derive_states` fields to an array of traits adds a derive expression to `Events` and `States` enums respectively. To derive Display, use `derive_more::Display`.
+Setting `events_attr` and `states_attr` fields to a list of attributes to `Events` and `States` enums respectively. To derive Display, use `derive_more::Display`.
 
 
 ```rust
 use core::Debug;
 use derive_more::Display;
 // ...
 statemachine!{
-    derive_states: [Debug, Display],
-    derive_events: [Debug, Display],
+    states_attr: #[derive(Debug, Display)],
+    events_attr: #[derive(Debug, Display)],
     transitions: {
         *State1 + Event1 = State2,
     }
@@ -409,7 +409,7 @@ fn log_action(&self, action: &'static str) {}
 fn log_state_change(&self, new_state: &States) {}
 ```
 
-See `examples/state_machine_logger.rs` for an example which uses `derive_states` and `derive_events` to derive `Debug` implementations for easy logging.
+See `examples/state_machine_logger.rs` for an example which uses `states_attr` and `events_attr` to derive `Debug` implementations for easy logging.
 
 ## Contributors
 

docs/dsl.md

@@ -23,11 +23,11 @@ statemachine!{
     // error type instead of `()`.
     custom_error: false,
 
-    // [Optional] A list of derive names for the generated `States` and `Events`
-    // enumerations respectively. For example, to `#[derive(Debug)]`, these
-    // would both be specified as `[Debug]`.
-    derive_states: [],
-    derive_events: [],
+    // [Optional] A list of attributes for the generated `States` and `Events`
+    // enumerations respectively. For example, to `#[derive(Debug)]` and `#[repr(u8)], these
+    // would both be specified in a list as follows:
+    states_attr: #[derive(Debug)] #[repr(u8)],
+    events_attr: #[derive(Debug)] #[repr(u8)],
 
     transitions: {
         // * denotes the starting state

examples/dominos.rs

@@ -5,8 +5,8 @@
 use smlang::statemachine;
 
 statemachine! {
-    derive_states: [Debug],
-    derive_events: [Debug],
+    states_attr: #[derive(Debug)],
+    events_attr: #[derive(Debug)],
     transitions: {
         *D0 +  ToD1 / to_d2  = D1,
         D1(Option<Events>) +  ToD2 / to_d3  = D2,

examples/named_ex1.rs

@@ -9,7 +9,7 @@ use smlang::statemachine;
 
 statemachine! {
     name: Linear,
-    derive_states: [Debug],
+    states_attr: #[derive(Debug)],
     transitions: {
         *State1 + Event1 = State2,
         State2 + Event2 = State3,

examples/state_machine_logger.rs

@@ -16,8 +16,8 @@ pub struct MyEventData(pub u32);
 pub struct MyStateData(pub u32);
 
 statemachine! {
-    derive_states: [Debug],
-    derive_events: [Debug],
+    states_attr: #[derive(Debug)],
+    events_attr: #[derive(Debug)],
     transitions: {
         *State1 + Event1(MyEventData) [guard1] / action1 = State2,
         State2(MyStateData) + Event2  [guard2] / action2 = State3,

macros/src/codegen.rs

@@ -539,8 +539,8 @@ pub fn generate_code(sm: &ParsedStateMachine) -> proc_macro2::TokenStream {
         quote! {#error_type_name}
     };
 
-    let derive_states_list = &sm.derive_states;
-    let derive_events_list = &sm.derive_events;
+    let states_attr_list = &sm.states_attr;
+    let events_attr_list = &sm.events_attr;
     // Build the states and events output
     quote! {
         /// This trait outlines the guards and actions that need to be implemented for the state
@@ -575,7 +575,7 @@ pub fn generate_code(sm: &ParsedStateMachine) -> proc_macro2::TokenStream {
 
         /// List of auto-generated states.
         #[allow(missing_docs)]
-        #[derive(#(#derive_states_list),*)]
+        #(#states_attr_list)*
         pub enum #states_type_name <#state_lifetimes> { #(#state_list),* }
 
         /// Manually define PartialEq for #states_type_name based on variant only to address issue-#21
@@ -588,7 +588,7 @@ pub fn generate_code(sm: &ParsedStateMachine) -> proc_macro2::TokenStream {
 
         /// List of auto-generated events.
         #[allow(missing_docs)]
-        #[derive(#(#derive_events_list),*)]
+        #(#events_attr_list)*
         pub enum #events_type_name <#event_lifetimes> { #(#event_list),* }
 
         /// Manually define PartialEq for #events_type_name based on variant only to address issue-#21

macros/src/parser/mod.rs

@@ -16,7 +16,7 @@ use proc_macro2::{Span, TokenStream};
 use crate::parser::event::Transition;
 use std::collections::{hash_map, HashMap};
 use std::fmt;
-use syn::{parse, Ident, Type};
+use syn::{parse, Attribute, Ident, Type};
 use transition::StateTransition;
 pub type TransitionMap = HashMap<String, HashMap<String, EventMapping>>;
 
@@ -46,8 +46,8 @@ impl fmt::Display for AsyncIdent {
 #[derive(Debug)]
 pub struct ParsedStateMachine {
     pub name: Option<Ident>,
-    pub derive_states: Vec<Ident>,
-    pub derive_events: Vec<Ident>,
+    pub states_attr: Vec<Attribute>,
+    pub events_attr: Vec<Attribute>,
     pub temporary_context_type: Option<Type>,
     pub custom_error: bool,
     pub states: HashMap<String, Ident>,
@@ -242,8 +242,8 @@ impl ParsedStateMachine {
 
         Ok(ParsedStateMachine {
             name: sm.name,
-            derive_states: sm.derive_states,
-            derive_events: sm.derive_events,
+            states_attr: sm.states_attr,
+            events_attr: sm.events_attr,
             temporary_context_type: sm.temporary_context_type,
             custom_error: sm.custom_error,
             states,

macros/src/parser/state_machine.rs

@@ -1,14 +1,14 @@
 use super::transition::{StateTransition, StateTransitions};
-use syn::{braced, bracketed, parse, spanned::Spanned, token, Ident, Token, Type};
+use syn::{braced, parse, spanned::Spanned, token, Attribute, Ident, Token, Type};
 
 #[derive(Debug)]
 pub struct StateMachine {
     pub temporary_context_type: Option<Type>,
     pub custom_error: bool,
     pub transitions: Vec<StateTransition>,
     pub name: Option<Ident>,
-    pub derive_states: Vec<Ident>,
-    pub derive_events: Vec<Ident>,
+    pub states_attr: Vec<Attribute>,
+    pub events_attr: Vec<Attribute>,
 }
 
 impl StateMachine {
@@ -18,8 +18,8 @@ impl StateMachine {
             custom_error: false,
             transitions: Vec::new(),
             name: None,
-            derive_states: Vec::new(),
-            derive_events: Vec::new(),
+            states_attr: Vec::new(),
+            events_attr: Vec::new(),
         }
     }
 
@@ -106,38 +106,17 @@ impl parse::Parse for StateMachine {
                     input.parse::<Token![:]>()?;
                     statemachine.name = Some(input.parse::<Ident>()?);
                 }
-                "derive_states" => {
+
+                "states_attr" => {
                     input.parse::<Token![:]>()?;
-                    if input.peek(token::Bracket) {
-                        let content;
-                        bracketed!(content in input);
-                        loop {
-                            if content.is_empty() {
-                                break;
-                            };
-                            let trait_ = content.parse::<Ident>()?;
-                            statemachine.derive_states.push(trait_);
-                            if content.parse::<Token![,]>().is_err() {
-                                break;
-                            };
-                        }
-                    }
+                    statemachine.states_attr = Attribute::parse_outer(input)?;
                 }
-                "derive_events" => {
+
+                "events_attr" => {
                     input.parse::<Token![:]>()?;
-                    let content;
-                    bracketed!(content in input);
-                    loop {
-                        if content.is_empty() {
-                            break;
-                        };
-                        let trait_ = content.parse::<Ident>()?;
-                        statemachine.derive_events.push(trait_);
-                        if content.parse::<Token![,]>().is_err() {
-                            break;
-                        };
-                    }
+                    statemachine.events_attr = Attribute::parse_outer(input)?;
                 }
+
                 keyword => {
                     return Err(parse::Error::new(
                         input.span(),
@@ -146,8 +125,8 @@ impl parse::Parse for StateMachine {
                                 \"transitions\", \
                                 \"temporary_context\", \
                                 \"custom_error\", \
-                                \"derive_states\", \
-                                \"derive_events\"
+                                \"states_attr\", \
+                                \"events_attr\"
                                 ]",
                             keyword
                         ),

src/lib.rs

@@ -22,8 +22,8 @@
 //!
 //! statemachine! {
 //!     name: Sample,
-//!     derive_states: [Debug],
-//!     derive_events: [Clone, Debug],
+//!     states_attr: #[derive(Debug)],
+//!     events_attr: #[derive(Clone, Debug)],
 //!     transitions: {
 //!         *Init + InitEvent [ guard_init ] / action_init = Ready,
 //!     }

tests/test.rs

@@ -121,8 +121,8 @@ fn multiple_lifetimes() {
 #[test]
 fn derive_display_events_states() {
     statemachine! {
-        derive_events: [Debug,Display],
-        derive_states: [Debug,Display],
+        events_attr: #[derive(Debug,Display)],
+        states_attr: #[derive(Debug,Display)],
         transitions: {
             *Init + Event = End,
         }
@@ -145,8 +145,8 @@ fn derive_display_events_states() {
 fn named_derive_display_events_states() {
     statemachine! {
         name: SM,
-        derive_events: [Debug,Display],
-        derive_states: [Debug,Display],
+        events_attr: #[derive(Debug,Display)],
+        states_attr: #[derive(Debug,Display)],
         transitions: {
             *Init + Event = End,
         }
@@ -205,7 +205,7 @@ fn guard_expressions() {
     pub struct Entry(pub u32);
 
     statemachine! {
-        derive_states: [Display, Debug],
+        states_attr: #[derive(Display, Debug)],
         transitions: {
             *Init + Login(&'a Entry) [valid_entry] / attempt = LoggedIn,
             Init + Login(&'a Entry) [!valid_entry && !too_many_attempts] / attempt = Init,
@@ -380,7 +380,7 @@ fn test_internal_transition_with_data() {
             // State4(State3Data) + Event3 / action_3 = State4(State3Data),
             _ + Event3 / action_3 = _,
         },
-        derive_states: [Debug, Clone,  Copy, Eq ]
+        states_attr: #[derive(Debug, Clone,  Copy, Eq)]
     }
     /// Context
     #[derive(Default, Debug, PartialEq, Eq)]
@@ -463,7 +463,7 @@ fn test_wildcard_states_and_internal_transitions() {
             _ + Event1 / increment_count,      // Internal transition (implicit: omitting target state)
             _ + Event3 / increment_count = _ , // Internal transition (explicit: using _ as target state)
         },
-        derive_states: [Debug, Clone,  Copy]
+        states_attr: #[derive(Debug, Clone,  Copy)]
     }
     #[derive(Debug)]
     pub struct Context {
@@ -487,3 +487,33 @@ fn test_wildcard_states_and_internal_transitions() {
     assert!(sm.process_event(Events::Event2).is_err()); // InvalidEvent
     assert_eq!(States::State3, sm.state);
 }
+#[test]
+fn test_specify_attrs() {
+    #![deny(non_camel_case_types)]
+    use serde::Serialize;
+    statemachine! {
+        transitions: {
+            *State1 + tostate2 = State2,
+            State2 + tostate3 / increment_count = State3
+        },
+        states_attr: #[derive(Debug, Clone, Copy, Serialize)] #[non_exhaustive] #[repr(u8)] #[serde(tag="type")],
+        events_attr: #[derive(Debug)] #[allow(non_camel_case_types)]
+    }
+
+    #[derive(Debug, Default)]
+    pub struct Context {
+        count: u32,
+    }
+
+    impl StateMachineContext for Context {
+        fn increment_count(&mut self) -> Result<(), ()> {
+            self.count += 1;
+            Ok(())
+        }
+    }
+    let mut sm = StateMachine::new(Context::default());
+
+    assert_eq!(sm.state().clone(), States::State1);
+    assert_transition!(sm, Events::tostate2, States::State2, 0);
+    assert_transition!(sm, Events::tostate3, States::State3, 1);
+}