add support for different types of mutability

effers-derive/src/intermediate_structs.rs

@@ -0,0 +1,81 @@
+use proc_macro2::{Span, TokenStream};
+use quote::quote;
+use syn::{Ident, Path};
+
+use crate::{lette::LettersIter, Args};
+
+pub struct IntermediateStruct {
+    pub tokens: TokenStream,
+    pub id: Ident,
+    pub traits: Vec<Path>,
+    pub letters: Vec<Ident>,
+    pub generics: TokenStream,
+}
+
+impl IntermediateStruct {
+    pub fn new(
+        tokens: TokenStream,
+        id: Ident,
+        traits: Vec<Path>,
+        letters: Vec<Ident>,
+        generics: TokenStream,
+    ) -> Self {
+        Self {
+            tokens,
+            id,
+            traits,
+            letters,
+            generics,
+        }
+    }
+}
+
+pub fn intermediate_structs(args: &Args, prog_name: &Ident) -> Vec<IntermediateStruct> {
+    let struct_with = format!("{}With", prog_name);
+    args.effects
+        .iter()
+        .fold(
+            (vec![], struct_with, vec![]),
+            |(mut structs, name, mut traits), eff| {
+                let name = format!("{}{}", &name, &eff.name);
+
+                traits.push(eff.path.clone());
+
+                // kinda messy
+                let letters = LettersIter::new()
+                    .take(traits.len())
+                    .map(|c| Ident::new(&c.to_string(), Span::call_site()));
+                let generics = traits
+                    .iter()
+                    .zip(letters.clone())
+                    .map(|(t, c)| quote!(#c: #t,))
+                    .collect::<TokenStream>();
+
+                let id = Ident::new(&name, Span::call_site());
+                let last = if let Some(&IntermediateStruct {
+                    ref id,
+                    ref letters,
+                    ..
+                }) = &structs.last()
+                {
+                    let gen = letters.iter().map(|l| quote!(#l,)).collect::<TokenStream>();
+                    quote!(#id<#gen>)
+                } else {
+                    quote!(#prog_name)
+                };
+                let last_letter = letters.clone().last();
+                structs.push(IntermediateStruct::new(
+                    quote! {
+                        struct #id<#generics>(#last, #last_letter);
+                    },
+                    id,
+                    traits.clone(),
+                    letters.collect::<Vec<_>>(),
+                    generics,
+                ));
+
+                (structs, name, traits)
+            },
+        )
+        .0
+}

effers-derive/src/lette.rs

@@ -0,0 +1,26 @@
+#[derive(Clone, Copy)]
+pub struct LettersIter {
+    idx: u32,
+}
+
+impl LettersIter {
+    pub fn new() -> Self {
+        Self {
+            idx: 'A' as u32 - 1,
+        }
+    }
+}
+impl Iterator for LettersIter {
+    type Item = char;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        for _ in 0..100 {
+            self.idx += 1;
+            if let Some(c) = char::from_u32(self.idx) {
+                return Some(c);
+            }
+        }
+
+        None
+    }
+}

effers-derive/src/lib.rs

@@ -3,10 +3,13 @@ use proc_macro2::{Span, TokenStream};
 use quote::quote;
 use syn::token::{Mut, SelfValue};
 use syn::visit_mut::VisitMut;
-use syn::{parse_macro_input, Expr, ExprCall, FnArg, Ident, ItemFn, Path, PathSegment, Receiver};
+use syn::{parse_macro_input, Expr, ExprCall, FnArg, Ident, ItemFn, PathSegment, Receiver};
 
 mod parse;
 use parse::Args;
+mod intermediate_structs;
+mod lette;
+use intermediate_structs::*;
 
 #[proc_macro_attribute]
 pub fn program(
@@ -30,33 +33,6 @@ pub fn program(
     proc_macro::TokenStream::from(out)
 }
 
-#[derive(Clone, Copy)]
-struct LettersIter {
-    idx: u32,
-}
-
-impl LettersIter {
-    fn new() -> Self {
-        Self {
-            idx: 'A' as u32 - 1,
-        }
-    }
-}
-impl Iterator for LettersIter {
-    type Item = char;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        for _ in 0..100 {
-            self.idx += 1;
-            if let Some(c) = char::from_u32(self.idx) {
-                return Some(c);
-            }
-        }
-
-        None
-    }
-}
-
 /// takes in the function contents, and returns the structs n stuff
 fn rewrite_item_into_struct(func: ItemFn, args: Args) -> TokenStream {
     let prog_name = (&args.name).clone().unwrap();
@@ -87,82 +63,6 @@ fn rewrite_item_into_struct(func: ItemFn, args: Args) -> TokenStream {
     TokenStream::from(out)
 }
 
-struct IntermediateStruct {
-    tokens: TokenStream,
-    id: Ident,
-    traits: Vec<Path>,
-    letters: Vec<Ident>,
-    generics: TokenStream,
-}
-
-impl IntermediateStruct {
-    fn new(
-        tokens: TokenStream,
-        id: Ident,
-        traits: Vec<Path>,
-        letters: Vec<Ident>,
-        generics: TokenStream,
-    ) -> Self {
-        Self {
-            tokens,
-            id,
-            traits,
-            letters,
-            generics,
-        }
-    }
-}
-
-fn intermediate_structs(args: &Args, prog_name: &Ident) -> Vec<IntermediateStruct> {
-    let struct_with = format!("{}With", prog_name);
-    args.effects
-        .iter()
-        .fold(
-            (vec![], struct_with, vec![]),
-            |(mut structs, name, mut traits), eff| {
-                let name = format!("{}{}", &name, &eff.name);
-
-                traits.push(eff.path.clone());
-
-                // kinda messy
-                let letters = LettersIter::new()
-                    .take(traits.len())
-                    .map(|c| Ident::new(&c.to_string(), Span::call_site()));
-                let generics = traits
-                    .iter()
-                    .zip(letters.clone())
-                    .map(|(t, c)| quote!(#c: #t,))
-                    .collect::<TokenStream>();
-
-                let id = Ident::new(&name, Span::call_site());
-                let last = if let Some(&IntermediateStruct {
-                    ref id,
-                    ref letters,
-                    ..
-                }) = &structs.last()
-                {
-                    let gen = letters.iter().map(|l| quote!(#l,)).collect::<TokenStream>();
-                    quote!(#id<#gen>)
-                } else {
-                    quote!(#prog_name)
-                };
-                let last_letter = letters.clone().last();
-                structs.push(IntermediateStruct::new(
-                    quote! {
-                        struct #id<#generics>(#last, #last_letter);
-                    },
-                    id,
-                    traits.clone(),
-                    letters.collect::<Vec<_>>(),
-                    generics,
-                ));
-
-                (structs, name, traits)
-            },
-        )
-        .0
-}
-
 fn impls(prog_name: &Ident, intermediate_structs: &Vec<IntermediateStruct>) -> TokenStream {
     let mut impls = vec![];
     let mut id = quote!(#prog_name);
@@ -268,7 +168,8 @@ impl<'a> syn::visit_mut::VisitMut for FuncRewriter<'a> {
                         // then change the parameters so the handler is the first
                         // get the effect's index, and add the inverse num of `.0`s
                         let idx = eff_len - (i + 1);
-                        let s = format!("&mut self{}.1", ".0".repeat(idx));
+                        let m = if func.mut_token.is_some() { "mut " } else { "" };
+                        let s = format!("&{}self{}.1", m, ".0".repeat(idx));
                         let expr: Expr = syn::parse_str(&s).unwrap();
                         node.args.insert(0, expr);
                     }

examples/main.rs

@@ -1,6 +1,6 @@
 use effers::program;
 
-#[program(Smth => Printer(print as p), Logger(debug, info))]
+#[program(Smth => Printer(print as p), Logger(mut debug, mut info))]
 fn smth(val: u8) -> u8 {
     p("hey hi hello");
 
@@ -10,7 +10,7 @@ fn smth(val: u8) -> u8 {
     val + 3
 }
 
-#[program(Printer(print as p))]
+#[program(Printer(mut print as p))]
 fn other_program() {
     p("hey hi hello");
 }
@@ -32,7 +32,7 @@ fn main() {
 }
 
 trait Printer {
-    fn print(&mut self, s: &str);
+    fn print(&self, s: &str);
 }
 trait Logger {
     fn debug(&mut self, s: &str);
@@ -41,7 +41,7 @@ trait Logger {
 
 struct IoPrinter;
 impl Printer for IoPrinter {
-    fn print(&mut self, s: &str) {
+    fn print(&self, s: &str) {
         println!("{}", s)
     }
 }

examples/path.rs

@@ -10,12 +10,12 @@ fn prog(val: u8) -> u8 {
 
 mod inc {
     pub trait Incrementer {
-        fn increment(&mut self, v: u8) -> u8;
+        fn increment(&self, v: u8) -> u8;
     }
 
     pub struct TestInc;
     impl Incrementer for TestInc {
-        fn increment(&mut self, v: u8) -> u8 {
+        fn increment(&self, v: u8) -> u8 {
             v + 3
         }
     }

src/lib.rs

@@ -4,21 +4,21 @@ pub use effers_derive::program;
 mod test {
     use super::*;
 
-    // #[program(Smth => Printer(print as p), Logger(debug, info), inc::Incrementer(increment))]
-    // fn smth(val: u8) -> u8 {
-    //     let s = p("hey hi hello");
+    #[program(Smth => Printer(print as p), Logger(mut debug, mut info), inc::Incrementer(mut increment))]
+    fn smth(val: u8) -> u8 {
+        let s = p("hey hi hello");
 
-    //     debug("this is a debug-level log");
-    //     info("this is a info-level log");
+        debug("this is a debug-level log");
+        info("this is a info-level log");
 
-    //     let _s = p("hey hi hello");
+        let _s = p("hey hi hello");
 
-    //     dbg!(s);
+        dbg!(s);
 
-    //     let x = increment(val);
-    //     let y = increment(x);
-    //     x + y
-    // }
+        let x = increment(val);
+        let y = increment(x);
+        x + y
+    }
 
     trait Printer {
         fn print(&self, s: &str) -> &str;