init promkit-derive crate

Cargo.toml

@@ -3,4 +3,5 @@ resolver = "2"
 members = [
   "promkit",
   "promkit-async",
+  "promkit-derive",
 ]

promkit-derive/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "promkit-derive"
+version = "0.1.0"
+authors = ["ynqa <[email protected]>"]
+edition = "2021"
+description = "A derive macro for promkit"
+repository = "https://github.com/ynqa/promkit"
+license = "MIT"
+readme = "README.md"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = { version = "2.0.52", features = ["full"] }
+quote = "1.0"
+proc-macro2 = "1.0"
+promkit = { path = "../promkit", version = "0.4.0" }

promkit-derive/examples/example.rs

@@ -0,0 +1,26 @@
+use promkit::{crossterm::style::Color, style::StyleBuilder};
+use promkit_derive::Promkit;
+
+#[derive(Default, Debug, Promkit)]
+struct Profile {
+    #[readline(
+        prefix = "What is your name?",
+        prefix_style = StyleBuilder::new().fgc(Color::DarkCyan).build(),
+    )]
+    name: String,
+
+    #[readline(default)]
+    hobby: Option<String>,
+
+    #[readline(prefix = "How old are you?", ignore_invalid_attr = "nothing")]
+    age: usize,
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut ret = Profile::default();
+    ret.readline_name()?;
+    ret.readline_hobby()?;
+    ret.readline_age()?;
+    dbg!(ret);
+    Ok(())
+}

promkit-derive/src/lib.rs

@@ -0,0 +1,57 @@
+extern crate proc_macro;
+
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::{parse::Error, parse_macro_input, spanned::Spanned, DeriveInput};
+
+#[proc_macro_derive(Promkit, attributes(readline))]
+pub fn promkit_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let ast = parse_macro_input!(input as DeriveInput);
+    match impl_promkit_derive(&ast) {
+        Ok(token) => token.into(),
+        Err(e) => e.to_compile_error().into(),
+    }
+}
+
+mod readline;
+
+fn impl_promkit_derive(ast: &DeriveInput) -> Result<TokenStream, Error> {
+    let fields = match &ast.data {
+        syn::Data::Struct(s) => match &s.fields {
+            syn::Fields::Named(fields) => &fields.named,
+            // tuple struct is like `struct Point(f32, f32);`
+            syn::Fields::Unnamed(_) => {
+                return Err(Error::new(ast.span(), "Not support tuple structs"))
+            }
+            // unit struct is like `struct Marker;`
+            syn::Fields::Unit => return Err(Error::new(ast.span(), "Not support unit structs")),
+        },
+        syn::Data::Enum(_) => return Err(Error::new(ast.span(), "Not support enums")),
+        syn::Data::Union(_) => return Err(Error::new(ast.span(), "Not support unions")),
+    };
+
+    let mut fns = quote! {};
+
+    for field in fields.iter() {
+        for attr in field.attrs.iter() {
+            #[allow(clippy::single_match)]
+            match attr.path().get_ident().unwrap().to_string().as_str() {
+                "readline" => {
+                    let expr = readline::impl_promkit_per_field(field, attr)?;
+                    fns = quote! {
+                        #fns
+                        #expr
+                    };
+                }
+                _ => (),
+            }
+        }
+    }
+
+    let name = &ast.ident;
+    Ok(quote! {
+        impl #name {
+            #fns
+        }
+    })
+}

promkit-derive/src/readline.rs

@@ -0,0 +1,174 @@
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse::Error, punctuated::Punctuated, spanned::Spanned, Meta, MetaList, MetaNameValue, Token,
+};
+
+pub fn impl_promkit_per_field(
+    field: &syn::Field,
+    attr: &syn::Attribute,
+) -> Result<TokenStream, Error> {
+    let readline_preset: TokenStream = match &attr.meta {
+        Meta::List(list) => {
+            let results = [parse_default_meta(list), parse_kvs_meta(list)];
+            let errors: Vec<Error> = results
+                .iter()
+                .filter_map(|r| r.as_ref().err().cloned())
+                .collect();
+
+            if errors.len() == results.len() {
+                let error_messages = errors
+                    .iter()
+                    .map(|e| e.to_string())
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                Err(Error::new(
+                    list.span(),
+                    format!("Errors: {}", error_messages),
+                ))
+            } else {
+                results
+                    .into_iter()
+                    .find_map(Result::ok)
+                    .ok_or_else(|| Error::new(list.span(), "Unexpected error"))
+            }
+        }?,
+        others => {
+            return Err(Error::new(
+                others.span(),
+                format!(
+                    "Support only readline(default), or readline(key=value, ...), but got {}",
+                    others.to_token_stream()
+                ),
+            ))
+        }
+    };
+
+    let field_ident = field.ident.as_ref().unwrap();
+    let preset_fn = syn::Ident::new(&format!("readline_{}", field_ident), field_ident.span());
+
+    match &field.ty {
+        syn::Type::Path(typ) => {
+            let last_segment = typ.path.segments.last().unwrap();
+            match last_segment.ident.to_string().as_str() {
+                "Option" => {
+                    if let syn::PathArguments::AngleBracketed(args) = &last_segment.arguments {
+                        if let Some(syn::GenericArgument::Type(inner_type)) = args.args.first() {
+                            return Ok(quote! {
+                                pub fn #preset_fn(&mut self) -> Result<(), Box<dyn std::error::Error>> {
+                                    let value_str = #readline_preset?;
+                                    let parsed_value = value_str.parse::<#inner_type>()
+                                        .map_or_else(|_| None, Some);
+                                    self.#field_ident = parsed_value;
+                                    Ok(())
+                                }
+                            });
+                        }
+                    }
+                    Err(Error::new(
+                        last_segment.span(),
+                        format!("Support Option<T> but got {}", typ.to_token_stream()),
+                    ))
+                }
+                _ => {
+                    let ty = typ.to_token_stream();
+                    Ok(quote! {
+                        pub fn #preset_fn(&mut self) -> Result<(), Box<dyn std::error::Error>> {
+                            let value_str = #readline_preset?;
+                            let parsed_value = value_str.parse::<#ty>()?;
+                            self.#field_ident = parsed_value;
+                            Ok(())
+                        }
+                    })
+                }
+            }
+        }
+        ty => Err(Error::new(
+            ty.span(),
+            format!(
+                "Support only Path for field type but got {}",
+                ty.to_token_stream()
+            ),
+        )),
+    }
+}
+
+fn parse_default_meta(list: &MetaList) -> Result<TokenStream, Error> {
+    match list.tokens.to_string().as_str() {
+        "default" => Ok(quote! {
+            promkit::preset::readline::Readline::default()
+                .prompt()?
+                .run()
+        }),
+        others => Err(Error::new(
+            list.span(),
+            format!("Support readline(default) but got {}", others),
+        )),
+    }
+}
+
+fn parse_kvs_meta(list: &MetaList) -> Result<TokenStream, Error> {
+    let mut ret = quote! {
+        promkit::preset::readline::Readline::default()
+    };
+
+    list.parse_args_with(Punctuated::<MetaNameValue, Token![,]>::parse_terminated)
+        .map_err(|e| {
+            Error::new(
+                list.span(),
+                format!(
+                    "Support readline(key=value, ...) but got {}, caused error: {}",
+                    list.tokens, e
+                ),
+            )
+        })?
+        .into_iter()
+        .for_each(
+            |entry| match entry.path.get_ident().unwrap().to_string().as_str() {
+                "prefix" => {
+                    let expr = entry.value;
+                    ret = quote! {
+                        #ret
+                        .prefix(format!("{} ", #expr))
+                    };
+                }
+                "mask" => {
+                    let expr = entry.value;
+                    ret = quote! {
+                        #ret
+                        .mask(#expr)
+                    };
+                }
+                "prefix_style" => {
+                    let expr = entry.value;
+                    ret = quote! {
+                        #ret
+                        .prefix_style(#expr)
+                    };
+                }
+                "active_char_style" => {
+                    let expr = entry.value;
+                    ret = quote! {
+                        #ret
+                        .active_char_style(#expr)
+                    };
+                }
+                "inactive_char_style" => {
+                    let expr = entry.value;
+                    ret = quote! {
+                        #ret
+                        .inactive_char_style(#expr)
+                    };
+                }
+                _ => (),
+            },
+        );
+
+    ret = quote! {
+        #ret
+        .prompt()?
+        .run()
+    };
+
+    Ok(ret)
+}