bendns' repos / rust-fsm
Finite state machines in rust; bendns fork to add types.
Diffstat (limited to 'rust-fsm-dsl/src/parser.rs')
-rw-r--r--rust-fsm-dsl/src/parser.rs80
1 files changed, 41 insertions, 39 deletions
diff --git a/rust-fsm-dsl/src/parser.rs b/rust-fsm-dsl/src/parser.rs
index b0fe02e..f1a9b67 100644
--- a/rust-fsm-dsl/src/parser.rs
+++ b/rust-fsm-dsl/src/parser.rs
@@ -1,4 +1,5 @@
use super::variant::Variant;
+use proc_macro2::TokenStream;
use syn::{
parse::{Error, Parse, ParseStream, Result},
token::Bracket,
@@ -116,26 +117,41 @@ pub struct StateMachineDef {
pub doc: Vec<Attribute>,
/// The visibility modifier (applies to all generated items)
pub visibility: Visibility,
- pub name: Ident,
+ pub state_name: ImplementationRequired,
+ pub input_name: ImplementationRequired,
+ pub output_name: ImplementationRequired,
pub initial_state: Variant,
pub transitions: Vec<TransitionDef>,
pub attributes: Vec<Attribute>,
- pub input_type: Option<Path>,
- pub state_type: Option<Path>,
- pub output_type: Option<Path>,
+}
+
+pub enum ImplementationRequired {
+ Yes(Ident),
+ No(Path),
+}
+
+impl ImplementationRequired {
+ pub fn tokenize(&self, f: impl Fn(&Ident) -> TokenStream) -> TokenStream {
+ match self {
+ ImplementationRequired::Yes(ident) => f(ident),
+ ImplementationRequired::No(_) => TokenStream::default(),
+ }
+ }
+ pub fn path(self) -> Path {
+ match self {
+ ImplementationRequired::Yes(ident) => ident.into(),
+ ImplementationRequired::No(path) => path,
+ }
+ }
}
impl Parse for StateMachineDef {
fn parse(input: ParseStream) -> Result<Self> {
- let mut state_machine_attributes = Vec::new();
let mut doc = Vec::new();
let attributes = Attribute::parse_outer(input)?
.into_iter()
.filter_map(|attribute| {
- if attribute.path().is_ident("state_machine") {
- state_machine_attributes.push(attribute);
- None
- } else if attribute.path().is_ident("doc") {
+ if attribute.path().is_ident("doc") {
doc.push(attribute);
None
} else {
@@ -144,34 +160,21 @@ impl Parse for StateMachineDef {
})
.collect();
- let mut input_type = None;
- let mut state_type = None;
- let mut output_type = None;
-
- for attribute in state_machine_attributes {
- attribute.parse_nested_meta(|meta| {
- let content;
- parenthesized!(content in meta.input);
- let p: Path = content.parse()?;
-
- if meta.path.is_ident("input") {
- input_type = Some(p);
- } else if meta.path.is_ident("state") {
- state_type = Some(p);
- } else if meta.path.is_ident("output") {
- output_type = Some(p);
- }
-
- Ok(())
- })?;
- }
-
let visibility = input.parse()?;
- let name = input.parse()?;
+ let i = || {
+ input
+ .parse::<Ident>()
+ .map(ImplementationRequired::Yes)
+ .or_else(|_| input.parse::<Path>().map(ImplementationRequired::No))
+ };
+ let state_name = i()?;
+ input.parse::<Token![:]>()?;
+ let initial_state = input.parse()?;
- let initial_state_content;
- parenthesized!(initial_state_content in input);
- let initial_state = initial_state_content.parse()?;
+ input.parse::<Token![=>]>()?;
+ let input_name = i()?;
+ input.parse::<Token![=>]>()?;
+ let output_name = i()?;
let transitions = input
.parse_terminated(TransitionDef::parse, Token![,])?
@@ -181,13 +184,12 @@ impl Parse for StateMachineDef {
Ok(Self {
doc,
visibility,
- name,
+ state_name,
+ input_name,
+ output_name,
initial_state,
transitions,
attributes,
- input_type,
- state_type,
- output_type,
})
}
}