fix!: Rename ArgValue to PossibleValue

In considering potential work for clap-rs#2683, I realized we might need a type to carry data for
each of the `multiple_values`.  `ArgValue` works both for that and for
possible values, so we need to come up with a better name for one or
both.  Changing `ArgValue`s name now would be ideal since its new in
clap3 and by renaming it, we can reduce churn for users.

While thinking about this, I realized I regularly get these mixed
up, so renaming `ArgValue` to `PossibleValue` I think will help clear
things up, regardless of clap-rs#2683.

clap_derive/src/derives/arg_enum.rs

@@ -47,8 +47,8 @@ pub fn gen_for_enum(name: &Ident, attrs: &[Attribute], e: &DataEnum) -> TokenStr
     );
 
     let lits = lits(&e.variants, &attrs);
-    let arg_values = gen_arg_values(&lits);
-    let to_arg_value = gen_to_arg_value(&lits);
+    let value_variants = gen_value_variants(&lits);
+    let to_possible_value = gen_to_possible_value(&lits);
 
     quote! {
         #[allow(dead_code, unreachable_code, unused_variables)]
@@ -64,8 +64,8 @@ pub fn gen_for_enum(name: &Ident, attrs: &[Attribute], e: &DataEnum) -> TokenStr
         )]
         #[deny(clippy::correctness)]
         impl clap::ArgEnum for #name {
-            #arg_values
-            #to_arg_value
+            #value_variants
+            #to_possible_value
         }
     }
 }
@@ -89,7 +89,7 @@ fn lits(
                 let name = attrs.cased_name();
                 Some((
                     quote! {
-                        clap::ArgValue::new(#name)
+                        clap::PossibleValue::new(#name)
                         #fields
                     },
                     variant.ident.clone(),
@@ -99,7 +99,7 @@ fn lits(
         .collect::<Vec<_>>()
 }
 
-fn gen_arg_values(lits: &[(TokenStream, Ident)]) -> TokenStream {
+fn gen_value_variants(lits: &[(TokenStream, Ident)]) -> TokenStream {
     let lit = lits.iter().map(|l| &l.1).collect::<Vec<_>>();
 
     quote! {
@@ -109,11 +109,11 @@ fn gen_arg_values(lits: &[(TokenStream, Ident)]) -> TokenStream {
     }
 }
 
-fn gen_to_arg_value(lits: &[(TokenStream, Ident)]) -> TokenStream {
+fn gen_to_possible_value(lits: &[(TokenStream, Ident)]) -> TokenStream {
     let (lit, variant): (Vec<TokenStream>, Vec<Ident>) = lits.iter().cloned().unzip();
 
     quote! {
-        fn to_arg_value<'a>(&self) -> Option<clap::ArgValue<'a>> {
+        fn to_possible_value<'a>(&self) -> Option<clap::PossibleValue<'a>> {
             match self {
                 #(Self::#variant => Some(#lit),)*
                 _ => None

clap_derive/src/derives/args.rs

@@ -372,7 +372,7 @@ pub fn gen_augment(
 
 fn gen_arg_enum_possible_values(ty: &Type) -> TokenStream {
     quote_spanned! { ty.span()=>
-        .possible_values(<#ty as clap::ArgEnum>::value_variants().iter().filter_map(clap::ArgEnum::to_arg_value))
+        .possible_values(<#ty as clap::ArgEnum>::value_variants().iter().filter_map(clap::ArgEnum::to_possible_value))
     }
 }
 

clap_derive/src/dummies.rs

@@ -82,7 +82,7 @@ pub fn arg_enum(name: &Ident) {
             fn from_str(_input: &str, _case_insensitive: bool) -> Result<Self, String> {
                 unimplemented!()
             }
-            fn to_arg_value<'a>(&self) -> Option<clap::ArgValue<'a>>{
+            fn to_possible_value<'a>(&self) -> Option<clap::PossibleValue<'a>>{
                 unimplemented!()
             }
         }

clap_derive/tests/arg_enum.rs

@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-use clap::{ArgEnum, ArgValue, Parser};
+use clap::{ArgEnum, Parser, PossibleValue};
 
 #[test]
 fn basic() {
@@ -54,7 +54,7 @@ fn default_value() {
 
     impl std::fmt::Display for ArgChoice {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
-            std::fmt::Display::fmt(self.to_arg_value().unwrap().get_name(), f)
+            std::fmt::Display::fmt(self.to_possible_value().unwrap().get_name(), f)
         }
     }
 
@@ -370,10 +370,10 @@ fn skip_variant() {
     assert_eq!(
         ArgChoice::value_variants()
             .iter()
-            .map(ArgEnum::to_arg_value)
+            .map(ArgEnum::to_possible_value)
             .map(Option::unwrap)
             .collect::<Vec<_>>(),
-        vec![ArgValue::new("foo"), ArgValue::new("bar")]
+        vec![PossibleValue::new("foo"), PossibleValue::new("bar")]
     );
     assert!(ArgChoice::from_str("foo", true).is_ok());
     assert!(ArgChoice::from_str("bar", true).is_ok());

clap_generate/examples/value_hints.rs

@@ -23,7 +23,7 @@ fn build_cli() -> App<'static> {
         .arg(
             Arg::new("generator")
                 .long("generate")
-                .possible_values(Shell::arg_values()),
+                .possible_values(Shell::possible_values()),
         )
         .arg(
             Arg::new("unknown")

clap_generate/src/generators/shells/bash.rs

@@ -179,7 +179,7 @@ fn vals_for(o: &Arg) -> String {
         format!(
             "$(compgen -W \"{}\" -- \"${{cur}}\")",
             vals.iter()
-                .filter_map(ArgValue::get_visible_name)
+                .filter_map(PossibleValue::get_visible_name)
                 .collect::<Vec<_>>()
                 .join(" ")
         )

clap_generate/src/generators/shells/zsh.rs

@@ -372,7 +372,7 @@ fn value_completion(arg: &Arg) -> Option<String> {
                 "({})",
                 values
                     .iter()
-                    .filter_map(ArgValue::get_visible_name)
+                    .filter_map(PossibleValue::get_visible_name)
                     .collect::<Vec<_>>()
                     .join(" ")
             ))

clap_generate/src/lib.rs

@@ -36,7 +36,7 @@
 //!        .arg(
 //!            Arg::new("generator")
 //!                .long("generate")
-//!                .possible_values(Shell::arg_values()),
+//!                .possible_values(Shell::possible_values()),
 //!        )
 //! }
 //!

clap_generate/src/shell.rs

@@ -1,7 +1,7 @@
 use std::fmt::Display;
 use std::str::FromStr;
 
-use clap::{ArgEnum, ArgValue};
+use clap::{ArgEnum, PossibleValue};
 
 use crate::{generators, Generator};
 
@@ -23,16 +23,16 @@ pub enum Shell {
 
 impl Shell {
     /// Report all `possible_values`
-    pub fn arg_values() -> impl Iterator<Item = ArgValue<'static>> {
+    pub fn possible_values() -> impl Iterator<Item = PossibleValue<'static>> {
         Shell::value_variants()
             .iter()
-            .filter_map(ArgEnum::to_arg_value)
+            .filter_map(ArgEnum::to_possible_value)
     }
 }
 
 impl Display for Shell {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.to_arg_value()
+        self.to_possible_value()
             .expect("no values are skipped")
             .get_name()
             .fmt(f)
@@ -44,7 +44,7 @@ impl FromStr for Shell {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         for variant in Self::value_variants() {
-            if variant.to_arg_value().unwrap().matches(s, false) {
+            if variant.to_possible_value().unwrap().matches(s, false) {
                 return Ok(*variant);
             }
         }
@@ -64,13 +64,13 @@ impl ArgEnum for Shell {
         ]
     }
 
-    fn to_arg_value<'a>(&self) -> Option<ArgValue<'a>> {
+    fn to_possible_value<'a>(&self) -> Option<PossibleValue<'a>> {
         Some(match self {
-            Shell::Bash => ArgValue::new("bash"),
-            Shell::Elvish => ArgValue::new("elvish"),
-            Shell::Fish => ArgValue::new("fish"),
-            Shell::PowerShell => ArgValue::new("powershell"),
-            Shell::Zsh => ArgValue::new("zsh"),
+            Shell::Bash => PossibleValue::new("bash"),
+            Shell::Elvish => PossibleValue::new("elvish"),
+            Shell::Fish => PossibleValue::new("fish"),
+            Shell::PowerShell => PossibleValue::new("powershell"),
+            Shell::Zsh => PossibleValue::new("zsh"),
         })
     }
 }

src/build/arg/mod.rs

@@ -1,12 +1,12 @@
-mod arg_value;
 #[cfg(debug_assertions)]
 pub mod debug_asserts;
+mod possible_value;
 mod settings;
 #[cfg(test)]
 mod tests;
 mod value_hint;
 
-pub use self::arg_value::ArgValue;
+pub use self::possible_value::PossibleValue;
 pub use self::settings::{ArgFlags, ArgSettings};
 pub use self::value_hint::ValueHint;
 
@@ -102,7 +102,7 @@ pub struct Arg<'help> {
     pub(crate) short_aliases: Vec<(char, bool)>, // (name, visible)
     pub(crate) disp_ord: usize,
     pub(crate) unified_ord: usize,
-    pub(crate) possible_vals: Vec<ArgValue<'help>>,
+    pub(crate) possible_vals: Vec<PossibleValue<'help>>,
     pub(crate) val_names: Vec<&'help str>,
     pub(crate) num_vals: Option<usize>,
     pub(crate) max_occurs: Option<usize>,
@@ -231,7 +231,7 @@ impl<'help> Arg<'help> {
 
     /// Get the list of the possible values for this argument, if any
     #[inline]
-    pub fn get_possible_values(&self) -> Option<&[ArgValue]> {
+    pub fn get_possible_values(&self) -> Option<&[PossibleValue]> {
         if self.possible_vals.is_empty() {
             None
         } else {
@@ -1959,7 +1959,7 @@ impl<'help> Arg<'help> {
     ///
     /// **NOTE:** This setting only applies to [options] and [positional arguments]
     ///
-    /// **NOTE:** You can use both strings directly or use [`ArgValue`] if you want more control
+    /// **NOTE:** You can use both strings directly or use [`PossibleValue`] if you want more control
     /// over single possible values.
     ///
     /// # Examples
@@ -1971,16 +1971,16 @@ impl<'help> Arg<'help> {
     ///     .possible_values(["fast", "slow", "medium"])
     /// # ;
     /// ```
-    /// The same using [`ArgValue`]:
+    /// The same using [`PossibleValue`]:
     ///
     /// ```rust
-    /// # use clap::{App, Arg, ArgValue};
+    /// # use clap::{App, Arg, PossibleValue};
     /// Arg::new("mode").takes_value(true).possible_values([
-    ///     ArgValue::new("fast"),
+    ///     PossibleValue::new("fast"),
     /// // value with a help text
-    ///     ArgValue::new("slow").about("not that fast"),
+    ///     PossibleValue::new("slow").about("not that fast"),
     /// // value that is hidden from completion and help text
-    ///     ArgValue::new("medium").hidden(true),
+    ///     PossibleValue::new("medium").hidden(true),
     /// ])
     /// # ;
     /// ```
@@ -2020,7 +2020,7 @@ impl<'help> Arg<'help> {
     pub fn possible_values<I, T>(mut self, values: I) -> Self
     where
         I: IntoIterator<Item = T>,
-        T: Into<ArgValue<'help>>,
+        T: Into<PossibleValue<'help>>,
     {
         self.possible_vals
             .extend(values.into_iter().map(|value| value.into()));
@@ -2032,7 +2032,7 @@ impl<'help> Arg<'help> {
     ///
     /// **NOTE:** This setting only applies to [options] and [positional arguments]
     ///
-    /// **NOTE:** You can use both strings directly or use [`ArgValue`] if you want more control
+    /// **NOTE:** You can use both strings directly or use [`PossibleValue`] if you want more control
     /// over single possible values.
     ///
     /// # Examples
@@ -2046,16 +2046,16 @@ impl<'help> Arg<'help> {
     ///     .possible_value("medium")
     /// # ;
     /// ```
-    /// The same using [`ArgValue`]:
+    /// The same using [`PossibleValue`]:
     ///
     /// ```rust
-    /// # use clap::{App, Arg, ArgValue};
+    /// # use clap::{App, Arg, PossibleValue};
     /// Arg::new("mode").takes_value(true)
-    ///     .possible_value(ArgValue::new("fast"))
+    ///     .possible_value(PossibleValue::new("fast"))
     /// // value with a help text
-    ///     .possible_value(ArgValue::new("slow").about("not that fast"))
+    ///     .possible_value(PossibleValue::new("slow").about("not that fast"))
     /// // value that is hidden from completion and help text
-    ///     .possible_value(ArgValue::new("medium").hidden(true))
+    ///     .possible_value(PossibleValue::new("medium").hidden(true))
     /// # ;
     /// ```
     ///
@@ -2097,7 +2097,7 @@ impl<'help> Arg<'help> {
     /// [positional arguments]: Arg::index()
     pub fn possible_value<T>(mut self, value: T) -> Self
     where
-        T: Into<ArgValue<'help>>,
+        T: Into<PossibleValue<'help>>,
     {
         self.possible_vals.push(value.into());
         self.takes_value(true)