feat: support Vec<T>

sasakiyori · Nov 6, 2023 · c89ee52 · c89ee52
1 parent f587ebc
commit c89ee52
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Showing 3 changed files with 57 additions and 21 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "merge-cfg"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 authors = ["sasakiyori <[email protected]>"]
 license = "MIT"

diff --git a/README.md b/README.md
@@ -13,12 +13,14 @@ use merge_cfg::MergeCfg;
 struct Config {
     id: u64,
     name: String,
+    scores: Vec<i32>,
 }
 
 fn main() {
     let mut cfg = Config {
         id: 1,
         name: "abc".to_string(),
+        scores: vec![-1],
     };
     cfg.merge_cfg();
     println!("{:?}", cfg);
@@ -29,16 +31,19 @@ Command line arguments format: `{field}={value}`, field name should be the same
 
 ```shell
 $ cargo run
-Config { id: 1, name: "abc" }
+Config { id: 1, name: "abc", scores: [-1] }
 
 $ cargo run id=2
-Config { id: 2, name: "abc" }
+Config { id: 2, name: "abc", scores: [-1] }
 
 $ cargo run name=xyz
-Config { id: 1, name: "xyz" }
+Config { id: 1, name: "xyz", scores: [-1] }
 
-$ cargo run id=2 name=xyz
-Config { id: 2, name: "xyz" }
+$ cargo run scores=100 scores=-1000
+Config { id: 1, name: "abc", scores: [100, -1000] }
+
+$ cargo run id=2 name=xyz scores=100
+Config { id: 2, name: "xyz", scores: [100] }
 ```
 
 ## Roadmap

diff --git a/src/lib.rs b/src/lib.rs
@@ -1,8 +1,10 @@
 extern crate proc_macro;
 
-use proc_macro::TokenStream;
+use proc_macro::{Span, TokenStream};
 use quote::quote;
-use syn::{parse_macro_input, Data, DeriveInput, Fields};
+use syn::{
+    parse_macro_input, Data, DeriveInput, Fields, GenericArgument, Ident, PathArguments, Type,
+};
 
 #[proc_macro_derive(MergeCfg)]
 pub fn merge_cfg_derive(input: TokenStream) -> TokenStream {
@@ -18,10 +20,36 @@ pub fn merge_cfg_derive(input: TokenStream) -> TokenStream {
                     let field_name = field_ident.to_string();
                     let field_type = field.ty.clone();
                     // cast and set value
-                    merge_handle = quote! {
-                        #merge_handle
-                        #field_name => {
-                            self.#field_ident = kv[1].parse::<#field_type>().unwrap()
+                    match &field_type {
+                        // currently just support Vec<T>
+                        Type::Path(p) if p.path.segments.first().unwrap().ident.eq("Vec") => {
+                            if let PathArguments::AngleBracketed(generic_args) =
+                                &p.path.segments.first().unwrap().arguments
+                            {
+                                let args = &generic_args.args;
+                                if args.len().eq(&1) {
+                                    if let GenericArgument::Type(Type::Path(ap)) = &args[0] {
+                                        // get type string
+                                        let ty = ap.path.get_ident().unwrap().to_string();
+                                        // get type identity
+                                        let ty_ident = Ident::new(&ty, Span::call_site().into());
+                                        merge_handle = quote! {
+                                            #merge_handle
+                                            #field_name => {
+                                                self.#field_ident = v.iter().map(|s| s.parse::<#ty_ident>().unwrap()).collect()
+                                            }
+                                        };
+                                    }
+                                }
+                            }
+                        }
+                        _ => {
+                            merge_handle = quote! {
+                                #merge_handle
+                                #field_name => {
+                                    self.#field_ident = v.first().unwrap().parse::<#field_type>().unwrap()
+                                }
+                            };
                         }
                     };
                 }
@@ -36,17 +64,20 @@ pub fn merge_cfg_derive(input: TokenStream) -> TokenStream {
         impl #struct_ident {
             pub fn merge_cfg(&mut self) {
                 let args: Vec<String> = ::std::env::args().collect();
-                    if args.len() > 1 {
-                        for arg in args.iter().skip(1) {
-                            let kv: Vec<&str> = arg.split('=').collect();
-                            if kv.len() == 2 {
-                                match kv[0] {
-                                    #merge_handle
-                                    _ => {}
-                                }
-                            }
+                if args.len() > 1 {
+                    let mut map = ::std::collections::HashMap::<String, Vec<String>>::new();
+                    for arg in args.iter().skip(1) {
+                        if let Some((k, v)) = arg.split_once('=') {
+                            map.entry(k.to_string()).or_default().push(v.to_string());
                         }
                     }
+                    map.iter().for_each(|(k, v)| {
+                        match k.as_str() {
+                            #merge_handle
+                            _ => {},
+                        }
+                    });
+                }
             }
         }
     }