refactor: remove unnecessary `Default` bound from `Pickable` trait

2 files changed, 111 insertions, 9 deletions

diff --git a/mingling_picker/src/picker/parse.rs b/mingling_picker/src/picker/parse.rs
index f69e078..8a55e03 100644
--- a/mingling_picker/src/picker/parse.rs
+++ b/mingling_picker/src/picker/parse.rs
@@ -1,4 +1,13 @@
-use crate::{Pickable, PickerResult};
+// --------------------------------------------------------------------------------------------
+// I have to say, the code generated by this `internal_repeat!` macro is really UGLY.
+//
+// But I have to admit, this is a **trade-off**. To achieve the syntax of `pick().pick().pick()`
+// while ensuring type safety, this is the best approach I could think of.
+//
+// P.S. If there's a better way, please let me know. Thanks!
+// --------------------------------------------------------------------------------------------
+
+use crate::{Pickable, PickerArgInfo, PickerArgs, PickerFlagAttr, PickerResult, TagPhaseContext};
 use mingling_picker_macros::internal_repeat;
 
 internal_repeat!(1..=32 => {
@@ -7,11 +16,104 @@ internal_repeat!(1..=32 => {
 
 internal_repeat!(1..=32 => {
     impl<'a, (T$,+)> PickerPattern$<'a, (T$,+)>
-    where (T$: Pickable<'a> + Default,+)
+    where (T$: Pickable<'a>,+)
     {
         #[allow(clippy::type_complexity)]
-        pub fn parse(self) -> PickerResult<((T$,+))> {
-            todo!()
+        pub fn parse(mut self) -> PickerResult<((T$,+))> {
+            // ArgInfos
+            let arg_infos: [PickerArgInfo; $] = [
+              (
+                  PickerArgInfo::from(self.flag_$),
+              +)
+            ];
+
+            // Read & sort attrs
+            let mut attrs: [
+                (
+                    // Flag Attr
+                    PickerFlagAttr,
+
+                    // Tag Func
+                    Box<dyn FnOnce(&PickerArgs<'a>) -> Vec<usize>>,
+
+                    // Pick Func
+                    Box<dyn FnOnce(&[&str])>,
+
+                    // Index
+                    usize
+                )
+                ; $] = [
+                (
+                    (
+                        // Flag Attr
+                        T$::get_attr(self.flag_$),
+
+                        // Tag Func
+                        Box::new(|args| {
+                            let ctx = TagPhaseContext {
+                                arg_info: &arg_infos[$],
+                                args,
+                            };
+                            T$::tag(ctx)
+                        }),
+
+                        // Pick Func
+                        Box::new(|args| {
+                            self.result_$ = match T$::pick(args) {
+                                PickerResult::Parsed(mut value) => {
+                                    // Postprocess
+                                    if let Some(post) = self.post_$ {
+                                        value = post(value);
+                                    }
+                                    PickerResult::Parsed(value)
+                                },
+                                other => {
+                                    if let Some(get_default) = self.default_$ {
+                                        let mut value = get_default();
+
+                                        // Postprocess
+                                        if let Some(post) = self.post_$ {
+                                            value = post(value);
+                                        }
+
+                                        PickerResult::Parsed(value)
+                                    } else {
+                                        other
+                                    }
+                                },
+
+                            }
+                        }),
+
+                        // Index
+                        $
+                    ),
+                +)
+            ];
+
+            // Sort by Attr Ord (descending)
+            attrs.sort_by(|a, b| b.0.cmp(&a.0));
+
+            // Parsing
+            for (_, tag_func, pick_func, _idx) in attrs {
+
+                // Tag phase
+                let tagged = tag_func(&self.args);
+                let mut args_to_pick: Vec<&str> = vec![];
+
+                for i in tagged {
+                    // Update args to pick
+                    args_to_pick.push(self.args.get(i).unwrap_or_default());
+                }
+
+                // Pick phase
+                pick_func(args_to_pick.as_slice());
+            }
+
+            // Sort by Index Ord
+            attrs.sort_by(|a, b| a.3.cmp(&b.3));
+
+            PickerResult::NotFound
         }
     }
 });
diff --git a/mingling_picker/src/picker/patterns.rs b/mingling_picker/src/picker/patterns.rs
index b12f151..4f54f9d 100644
--- a/mingling_picker/src/picker/patterns.rs
+++ b/mingling_picker/src/picker/patterns.rs
@@ -5,7 +5,7 @@ use crate::{Pickable, Picker, PickerArgs, PickerFlag, PickerResult};
 internal_repeat!(1..=32 => {
     #[doc(hidden)]
     pub struct PickerPattern$<'a, (T$,+)>
-    where (T$: Pickable<'a> + Default,+)
+    where (T$: Pickable<'a>,+)
     {
         pub args: PickerArgs<'a>,
         (
@@ -19,7 +19,7 @@ internal_repeat!(1..=32 => {
 
 internal_repeat!(1..=32 => {
     impl<'a, (T$,+)> PickerPattern$<'a, (T$,+)>
-    where (T$: Pickable<'a> + Default,+)
+    where (T$: Pickable<'a>,+)
     {
         /// Sets a default value provider for this flag.
         ///
@@ -70,7 +70,7 @@ internal_repeat!(1..=32 => {
 
 internal_repeat!(1..32 => {
    impl<'a, (T$,+)> PickerPattern$<'a, (T$,+)>
-   where (T$: Pickable<'a> + Default,+)
+   where (T$: Pickable<'a>,+)
    {
        #[allow(clippy::type_complexity)]
        /// Adds a new flag to the picking chain, returning a new `PickerPattern` with one more type parameter.
@@ -80,7 +80,7 @@ internal_repeat!(1..32 => {
        /// The new flag's result is initially `Unparsed`.
        pub fn pick<N>(self, flag: &'a PickerFlag<'a, N>) -> PickerPattern$+<'a, (T$,+), N>
        where
-           N: Pickable<'a> + Default,
+           N: Pickable<'a>,
        {
            PickerPattern$+ {
                // Args
@@ -111,7 +111,7 @@ impl<'a> Picker<'a> {
     /// The result is initially `Unparsed`.
     pub fn pick<N>(self, flag: &'a PickerFlag<'a, N>) -> PickerPattern1<'a, N>
     where
-        N: Pickable<'a> + Default,
+        N: Pickable<'a>,
     {
         PickerPattern1 {
             args: self.args,