Add support for deriving grouped options for Vec<Vec<T>>

clap_derive/src/derives/args.rs

@@ -288,6 +288,14 @@ pub fn gen_augment(
                         }
                     }
 
+                    Ty::VecVec | Ty::OptionVecVec => {
+                        quote_spanned! { ty.span() =>
+                            .value_name(#value_name)
+                            #value_parser
+                            #action
+                        }
+                    }
+
                     Ty::Other => {
                         let required = item.find_default_method().is_none() && !override_required;
                         // `ArgAction::takes_values` is assuming `ArgAction::default_value` will be
@@ -431,7 +439,9 @@ pub fn gen_constructor(fields: &[(&Field, Item)]) -> TokenStream {
                     Ty::Unit |
                     Ty::Vec |
                     Ty::OptionOption |
-                    Ty::OptionVec => {
+                    Ty::OptionVec |
+                    Ty::VecVec |
+                    Ty::OptionVecVec => {
                         abort!(
                             ty.span(),
                             "{} types are not supported for subcommand",
@@ -470,7 +480,9 @@ pub fn gen_constructor(fields: &[(&Field, Item)]) -> TokenStream {
                     Ty::Unit |
                     Ty::Vec |
                     Ty::OptionOption |
-                    Ty::OptionVec => {
+                    Ty::OptionVec |
+                    Ty::VecVec |
+                    Ty::OptionVecVec => {
                         abort!(
                             ty.span(),
                             "{} types are not supported for flatten",
@@ -609,6 +621,7 @@ fn gen_parsers(
     let id = item.id();
     let get_one = quote_spanned!(span=> remove_one::<#convert_type>);
     let get_many = quote_spanned!(span=> remove_many::<#convert_type>);
+    let get_occurrences = quote_spanned!(span=> remove_occurrences::<#convert_type>);
     let deref = quote!(|s| s);
     let parse = quote_spanned!(span=> |s| ::std::result::Result::Ok::<_, clap::Error>(s));
 
@@ -665,6 +678,17 @@ fn gen_parsers(
             }
         }
 
+        Ty::VecVec => quote_spanned! { ty.span()=>
+            #arg_matches.#get_occurrences(#id)
+                .map(|g| g.map(::std::iter::Iterator::collect).collect::<Vec<Vec<_>>>())
+                .unwrap_or_else(Vec::new)
+        },
+
+        Ty::OptionVecVec => quote_spanned! { ty.span()=>
+            #arg_matches.#get_occurrences(#id)
+                .map(|g| g.map(::std::iter::Iterator::collect).collect::<Vec<Vec<_>>>())
+        },
+
         Ty::Other => {
             quote_spanned! { ty.span()=>
                 #arg_matches.#get_one(#id)

clap_derive/src/item.rs

@@ -1121,7 +1121,7 @@ impl Action {
 fn default_action(field_type: &Type, span: Span) -> Method {
     let ty = Ty::from_syn_ty(field_type);
     let args = match *ty {
-        Ty::Vec | Ty::OptionVec => {
+        Ty::Vec | Ty::OptionVec | Ty::VecVec | Ty::OptionVecVec => {
             quote_spanned! { span=>
                 clap::ArgAction::Append
             }

clap_derive/src/utils/ty.rs

@@ -11,9 +11,11 @@ use syn::{
 pub enum Ty {
     Unit,
     Vec,
+    VecVec,
     Option,
     OptionOption,
     OptionVec,
+    OptionVecVec,
     Other,
 }
 
@@ -24,13 +26,13 @@ impl Ty {
 
         if is_unit_ty(ty) {
             t(Unit)
-        } else if is_generic_ty(ty, "Vec") {
-            t(Vec)
+        } else if let Some(vt) = get_vec_ty(ty, Vec, VecVec) {
+            t(vt)
         } else if let Some(subty) = subty_if_name(ty, "Option") {
             if is_generic_ty(subty, "Option") {
                 t(OptionOption)
-            } else if is_generic_ty(subty, "Vec") {
-                t(OptionVec)
+            } else if let Some(vt) = get_vec_ty(subty, OptionVec, OptionVecVec) {
+                t(vt)
             } else {
                 t(Option)
             }
@@ -46,6 +48,8 @@ impl Ty {
             Self::Option => "Option<T>",
             Self::OptionOption => "Option<Option<T>>",
             Self::OptionVec => "Option<Vec<T>>",
+            Self::VecVec => "Vec<Vec<T>>",
+            Self::OptionVecVec => "Option<Vec<Vec<T>>>",
             Self::Other => "...other...",
         }
     }
@@ -55,9 +59,13 @@ pub fn inner_type(field_ty: &syn::Type) -> &syn::Type {
     let ty = Ty::from_syn_ty(field_ty);
     match *ty {
         Ty::Vec | Ty::Option => sub_type(field_ty).unwrap_or(field_ty),
-        Ty::OptionOption | Ty::OptionVec => {
+        Ty::OptionOption | Ty::OptionVec | Ty::VecVec => {
             sub_type(field_ty).and_then(sub_type).unwrap_or(field_ty)
         }
+        Ty::OptionVecVec => sub_type(field_ty)
+            .and_then(sub_type)
+            .and_then(sub_type)
+            .unwrap_or(field_ty),
         _ => field_ty,
     }
 }
@@ -139,3 +147,19 @@ where
 {
     iter.next().filter(|_| iter.next().is_none())
 }
+
+#[cfg(feature = "unstable-v5")]
+fn get_vec_ty(ty: &Type, vec_ty: Ty, vecvec_ty: Ty) -> Option<Ty> {
+    subty_if_name(ty, "Vec").map(|subty| {
+        if is_generic_ty(subty, "Vec") {
+            vecvec_ty
+        } else {
+            vec_ty
+        }
+    })
+}
+
+#[cfg(not(feature = "unstable-v5"))]
+fn get_vec_ty(ty: &Type, vec_ty: Ty, _vecvec_ty: Ty) -> Option<Ty> {
+    is_generic_ty(ty, "Vec").then(|| vec_ty)
+}

tests/derive/main.rs

@@ -22,6 +22,7 @@ mod macros;
 mod naming;
 mod nested_subcommands;
 mod non_literal_attributes;
+mod occurrences;
 mod options;
 mod privacy;
 mod raw_bool_literal;

tests/derive/occurrences.rs

@@ -0,0 +1,82 @@
+#![cfg(all(feature = "unstable-grouped", feature = "unstable-v5"))]
+use clap::Parser;
+
+#[test]
+fn test_vec_of_vec() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[arg(short = 'p', num_args = 2)]
+        points: Vec<Vec<i32>>,
+    }
+
+    assert_eq!(
+        Opt {
+            points: vec![vec![1, 2], vec![0, 0]]
+        },
+        Opt::try_parse_from(&["test", "-p", "1", "2", "-p", "0", "0"]).unwrap()
+    );
+}
+
+#[test]
+fn test_vec_of_vec_opt_out() {
+    fn parser(s: &str) -> Result<Vec<String>, std::convert::Infallible> {
+        Ok(s.split(',').map(str::to_owned).collect())
+    }
+
+    #[derive(Parser, PartialEq, Debug)]
+    struct Opt {
+        #[arg(value_parser = parser, short = 'p')]
+        arg: Vec<::std::vec::Vec<String>>,
+    }
+
+    assert_eq!(
+        Opt {
+            arg: vec![vec!["1".into(), "2".into()], vec!["a".into(), "b".into()]],
+        },
+        Opt::try_parse_from(["test", "-p", "1,2", "-p", "a,b"]).unwrap(),
+    );
+}
+
+#[test]
+fn test_vec_vec_empty() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[arg(short = 'p', num_args = 2)]
+        points: Vec<Vec<i32>>,
+    }
+
+    assert_eq!(
+        Opt { points: vec![] },
+        Opt::try_parse_from(&["test"]).unwrap()
+    );
+}
+
+#[test]
+fn test_option_vec_vec() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[arg(short = 'p', num_args = 2)]
+        points: Option<Vec<Vec<i32>>>,
+    }
+
+    assert_eq!(
+        Opt {
+            points: Some(vec![vec![1, 2], vec![3, 4]])
+        },
+        Opt::try_parse_from(&["test", "-p", "1", "2", "-p", "3", "4"]).unwrap()
+    );
+}
+
+#[test]
+fn test_option_vec_vec_empty() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[arg(short = 'p', num_args = 2)]
+        points: Option<Vec<Vec<i32>>>,
+    }
+
+    assert_eq!(
+        Opt { points: None },
+        Opt::try_parse_from(&["test"]).unwrap()
+    );
+}