Merge pull request #2 from teloxide/readme

added type safe arguments

Cargo.toml

@@ -9,7 +9,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-quote = "1.0.2"
+quote = "1.0.3"
 syn = "1.0.13"
 
 [lib]

Readme.md

@@ -0,0 +1,39 @@
+# teloxide-macros
+The teloxide's procedural macros.
+
+## Example
+```rust
+use teloxide::utils::command::BotCommand;
+#[derive(BotCommand, PartialEq, Debug)]
+#[command(rename = "lowercase")]
+enum AdminCommand {
+    Mute,
+    Ban,
+}
+let (command, args) = AdminCommand::parse("/ban 5 h", "bot_name").unwrap();
+assert_eq!(command, AdminCommand::Ban);
+assert_eq!(args, vec!["5", "h"]);
+```
+## Enum attributes
+ 1. `#[command(rename = "rule")]`
+Rename all commands by rule. Allowed rules are `lowercase`. If you will not
+use this attribute, commands will be parsed by their original names.
+
+ 2. `#[command(prefix = "prefix")]`
+Change a prefix for all commands (the default is `/`).
+
+ 3. `#[command(description = "description")]`
+Add a sumary description of commands before all commands.
+
+## Variant attributes
+ 1. `#[command(rename = "rule")]`
+Rename one command by a rule. Allowed rules are `lowercase`, `%some_name%`,
+where `%some_name%` is any string, a new name.
+
+ 2. `#[command(prefix = "prefix")]`
+Change a prefix for one command (the default is `/`).
+
+ 3. `#[command(description = "description")]`
+Add a description of one command.
+
+All variant attributes overlap the `enum` attributes.

src/command.rs

@@ -1,8 +1,8 @@
+use crate::enum_attributes::CommandEnum;
 use crate::{
     attr::{Attr, BotCommandAttribute},
     rename_rules::rename_by_rule,
 };
-use crate::enum_attributes::CommandEnum;
 
 pub struct Command {
     pub prefix: Option<String>,
@@ -40,7 +40,11 @@ impl Command {
         } else {
             "/"
         };
-        String::from(prefix) + &self.name
+        if let Some(rule) = &global_parameters.rename_rule {
+            String::from(prefix) + &rename_by_rule(&self.name, rule.as_str())
+        } else {
+            String::from(prefix) + &self.name
+        }
     }
 }
 

src/enum_attributes.rs

@@ -1,5 +1,6 @@
 use crate::attr::{Attr, BotCommandAttribute};
 
+#[derive(Debug)]
 pub struct CommandEnum {
     pub prefix: Option<String>,
     pub description: Option<String>,

src/fields_parse.rs

@@ -0,0 +1,13 @@
+extern crate quote;
+
+use quote::quote;
+use syn::FieldsUnnamed;
+
+pub fn impl_parse_args_unnamed(data: &FieldsUnnamed) -> quote::__private::TokenStream {
+    let iter = 0..data.unnamed.len();
+    let mut tokens = quote! {};
+    for _ in iter {
+        tokens.extend(quote! { CommandArgument::parse(&mut args)?, });
+    }
+    quote! { (#tokens) }
+}

src/lib.rs

@@ -1,10 +1,13 @@
 mod attr;
 mod command;
 mod enum_attributes;
+mod fields_parse;
 mod rename_rules;
 
 extern crate proc_macro;
+extern crate quote;
 extern crate syn;
+use crate::fields_parse::impl_parse_args_unnamed;
 use crate::{
     attr::{Attr, VecAttrs},
     command::Command,
@@ -12,7 +15,7 @@ use crate::{
 };
 use proc_macro::TokenStream;
 use quote::{quote, ToTokens};
-use syn::{parse_macro_input, DeriveInput, Variant};
+use syn::{parse_macro_input, DeriveInput, Fields, Variant};
 
 macro_rules! get_or_return {
     ($($some:tt)*) => {
@@ -36,10 +39,23 @@ pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
         Err(e) => return compile_error(e),
     };
 
-    let variants: Vec<&syn::Variant> = data_enum.variants.iter().map(|attr| attr).collect();
+    let variants: Vec<&syn::Variant> = data_enum.variants.iter().map(|variant| variant).collect();
+
+    let mut vec_impl_create = vec![];
+    for variant in &variants {
+        match &variant.fields {
+            Fields::Unnamed(fields) => {
+                vec_impl_create.push(impl_parse_args_unnamed(fields));
+            }
+            Fields::Unit => {
+                vec_impl_create.push(quote! {});
+            }
+            _ => panic!("only unnamed fields"), // TODO: named fields
+        }
+    }
 
     let mut variant_infos = vec![];
-    for variant in variants.iter() {
+    for variant in &variants {
         let mut attrs = Vec::new();
         for attr in &variant.attrs {
             match attr.parse_args::<VecAttrs>() {
@@ -59,13 +75,11 @@ pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
 
     let ident = &input.ident;
 
-    let fn_try_from = impl_try_parse_command(&variants, &variant_infos, &command_enum);
     let fn_descriptions = impl_descriptions(&variant_infos, &command_enum);
-    let fn_parse = impl_parse();
+    let fn_parse = impl_parse(&variants, &variant_infos, &command_enum, &vec_impl_create);
 
     let trait_impl = quote! {
         impl BotCommand for #ident {
-            #fn_try_from
             #fn_descriptions
             #fn_parse
         }
@@ -74,23 +88,7 @@ pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
     TokenStream::from(trait_impl)
 }
 
-fn impl_try_parse_command(variants: &[&Variant], infos: &[Command], global: &CommandEnum) -> impl ToTokens {
-    let matching_values = infos.iter().map(|c| c.get_matched_value(global));
-    let variant_ident = variants.iter().map(|variant| &variant.ident);
-
-    quote! {
-        fn try_from(value: &str) -> Option<Self> {
-            match value {
-                #(
-                    #matching_values => Some(Self::#variant_ident),
-                )*
-                _ => None
-            }
-        }
-    }
-}
-
-fn impl_descriptions(infos: &[Command], global: &CommandEnum) -> impl ToTokens {
+fn impl_descriptions(infos: &[Command], global: &CommandEnum) -> quote::__private::TokenStream {
     let global_description = if let Some(s) = &global.description {
         quote! { #s, "\n", }
     } else {
@@ -105,31 +103,44 @@ fn impl_descriptions(infos: &[Command], global: &CommandEnum) -> impl ToTokens {
     });
 
     quote! {
-        fn descriptions() -> &'static str {
-            std::concat!(#global_description #(#command, #description, '\n'),*)
+        fn descriptions() -> String {
+            std::concat!(#global_description #(#command, #description, '\n'),*).to_string()
         }
     }
 }
 
-fn impl_parse() -> impl ToTokens {
+fn impl_parse(
+    variants: &[&Variant],
+    infos: &[Command],
+    global: &CommandEnum,
+    variants_initialization: &[quote::__private::TokenStream],
+) -> quote::__private::TokenStream {
+    let matching_values = infos.iter().map(|c| c.get_matched_value(global));
+    let variant_ident = variants.iter().map(|variant| &variant.ident);
+
     quote! {
-         fn parse<N>(s: &str, bot_name: N) -> Option<(Self, Vec<&str>)>
+         fn parse<N>(s: &str, bot_name: N) -> Option<Self>
          where
-            N: Into<String>
+              N: Into<String>
          {
-            let mut words = s.split_whitespace();
-            let mut splited = words.next()?.split('@');
-            let command_raw = splited.next()?;
-            let bot = splited.next();
-            let bot_name = bot_name.into();
-            match bot {
-                Some(name) if name == bot_name => {}
-                None => {}
-                _ => return None,
-            }
-            let command = Self::try_from(command_raw)?;
-            Some((command, words.collect()))
-        }
+              let mut words = s.splitn(2, ' ');
+              let mut splited = words.next()?.split('@');
+              let command_raw = splited.next()?;
+              let bot = splited.next();
+              let bot_name = bot_name.into();
+              match bot {
+                  Some(name) if name == bot_name => {}
+                  None => {}
+                  _ => return None,
+              }
+              let mut args = words.next().unwrap_or("").to_string();
+              match command_raw {
+                   #(
+                        #matching_values => Some(Self::#variant_ident #variants_initialization),
+                   )*
+                   _ => None,
+              }
+         }
     }
 }