Merge pull request #301 from pacak/simplify-parse-any

Convert checker function inside ParseAny into a trait object
pacak · Sep 24, 2023 · 748138f · 748138f
2 parents a5b2501 + c76ed23
commit 748138f
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Showing 2 changed files with 22 additions and 24 deletions.
diff --git a/src/lib.rs b/src/lib.rs
@@ -1480,16 +1480,22 @@ where
 /// # See also
 /// [`literal`] - a specialized version of `any` that tries to parse a fixed literal
 #[must_use]
-pub fn any<I, T, F>(metavar: &str, check: F) -> ParseAny<T, I, F>
+pub fn any<I, T, F>(metavar: &str, check: F) -> ParseAny<T>
 where
     I: FromStr + 'static,
-    F: Fn(I) -> Option<T>,
+    F: Fn(I) -> Option<T> + 'static,
+    <I as std::str::FromStr>::Err: std::fmt::Display,
 {
     ParseAny {
         metavar: [(metavar, Style::Metavar)][..].into(),
         help: None,
-        check,
-        ctx: PhantomData,
+        check: Box::new(move |os: std::ffi::OsString| {
+            match crate::from_os_str::parse_os_str::<I>(os) {
+                Ok(v) => check(v),
+                Err(_) => None,
+            }
+        }),
+
         anywhere: false,
     }
 }
@@ -1507,8 +1513,8 @@ where
 /// [`any`] - a generic version of `literal` that uses function to decide if value is to be parsed
 /// or not.
 #[must_use]
-pub fn literal(val: &'static str) -> ParseAny<(), String, impl Fn(String) -> Option<()>> {
-    any("", move |s| if s == val { Some(()) } else { None })
+pub fn literal(val: &'static str) -> ParseAny<()> {
+    any("", move |s: String| if s == val { Some(()) } else { None })
         .metavar(&[(val, crate::buffer::Style::Literal)][..])
 }
 

diff --git a/src/params.rs b/src/params.rs
@@ -847,15 +847,14 @@ where
 
 /// Consume an arbitrary value that satisfies a condition, created with [`any`], implements
 /// [`anywhere`](ParseAny::anywhere).
-pub struct ParseAny<T, I, F> {
+pub struct ParseAny<T> {
     pub(crate) metavar: Doc,
     pub(crate) help: Option<Doc>,
-    pub(crate) ctx: PhantomData<(I, T)>,
-    pub(crate) check: F,
+    pub(crate) check: Box<dyn Fn(OsString) -> Option<T>>,
     pub(crate) anywhere: bool,
 }
 
-impl<T, I, F> ParseAny<T, I, F> {
+impl<T> ParseAny<T> {
     pub(crate) fn item(&self) -> Item {
         Item::Any {
             metavar: self.metavar.clone(),
@@ -894,27 +893,20 @@ impl<T, I, F> ParseAny<T, I, F> {
     }
 }
 
-impl<F, I, T> Parser<T> for ParseAny<T, I, F>
-where
-    I: FromStr + 'static,
-    F: Fn(I) -> Option<T>,
-    <I as std::str::FromStr>::Err: std::fmt::Display,
-{
+impl<T> Parser<T> for ParseAny<T> {
     fn eval(&self, args: &mut State) -> Result<T, Error> {
         for (ix, x) in args.items_iter() {
             let (os, next) = match x {
                 Arg::Short(_, next, os) | Arg::Long(_, next, os) => (os, *next),
                 Arg::ArgWord(os) | Arg::Word(os) | Arg::PosWord(os) => (os, false),
             };
-            if let Ok(i) = parse_os_str::<I>(os.clone()) {
-                if let Some(t) = (self.check)(i) {
-                    args.remove(ix);
-                    if next {
-                        args.remove(ix + 1);
-                    }
-
-                    return Ok(t);
+            if let Some(i) = (self.check)(os.clone()) {
+                args.remove(ix);
+                if next {
+                    args.remove(ix + 1);
                 }
+
+                return Ok(i);
             }
             if !self.anywhere {
                 break;