Add argument parser module with picker API

1 files changed, 116 insertions, 0 deletions

diff --git a/mingling/src/parser/picker.rs b/mingling/src/parser/picker.rs
new file mode 100644
index 0000000..dc8b8da
--- /dev/null
+++ b/mingling/src/parser/picker.rs
@@ -0,0 +1,116 @@
+use crate::parser::Argument;
+use mingling_core::Flag;
+
+pub mod builtin;
+
+#[doc(hidden)]
+pub struct Picker {
+    pub args: Argument,
+}
+
+impl Picker {
+    pub fn new(args: impl Into<Argument>) -> Picker {
+        Picker { args: args.into() }
+    }
+
+    pub fn pick<TNext>(mut self, val: impl Into<Flag>) -> Pick1<TNext>
+    where
+        TNext: Pickable<Output = TNext> + Default,
+    {
+        let v = TNext::pick(&mut self.args, val.into()).unwrap_or_default();
+        Pick1 {
+            args: self.args,
+            val_1: v,
+        }
+    }
+}
+
+impl<T: Into<Argument>> From<T> for Picker {
+    fn from(value: T) -> Self {
+        Picker::new(value)
+    }
+}
+
+pub trait Pickable {
+    type Output: Default;
+    fn pick(args: &mut Argument, flag: Flag) -> Option<Self::Output>;
+}
+
+#[doc(hidden)]
+macro_rules! define_pick_structs {
+    ($n:tt $($T:ident $val:ident),+) => {
+        #[doc(hidden)]
+        pub struct $n<$($T),+>
+        where
+            $($T: Pickable,)+
+        {
+            #[allow(dead_code)]
+            args: Argument,
+            $(pub $val: $T,)+
+        }
+
+        impl<$($T),+> From<$n<$($T),+>> for ($($T,)+)
+        where
+            $($T: Pickable,)+
+        {
+            fn from(pick: $n<$($T),+>) -> Self {
+                ($(pick.$val,)+)
+            }
+        }
+
+        impl<$($T),+> $n<$($T),+>
+        where
+            $($T: Pickable,)+
+        {
+            pub fn unpack(self) -> ($($T,)+) {
+                ($(self.$val,)+)
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+macro_rules! impl_pick_structs {
+    ($n:ident $next:ident $next_val:ident $($T:ident $val:ident),+) => {
+        impl<$($T),+> $n<$($T),+>
+        where
+            $($T: Pickable,)+
+        {
+            pub fn pick<TNext>(mut self, val: impl Into<mingling_core::Flag>) -> $next<$($T,)+ TNext>
+            where
+                TNext: Pickable<Output = TNext> + Default,
+            {
+                let v = TNext::pick(&mut self.args, val.into()).unwrap_or_default();
+                $next {
+                    args: self.args,
+                    $($val: self.$val,)+
+                    $next_val: v,
+                }
+            }
+        }
+    };
+}
+
+define_pick_structs! { Pick1 T1 val_1 }
+define_pick_structs! { Pick2 T1 val_1, T2 val_2 }
+define_pick_structs! { Pick3 T1 val_1, T2 val_2, T3 val_3 }
+define_pick_structs! { Pick4 T1 val_1, T2 val_2, T3 val_3, T4 val_4 }
+define_pick_structs! { Pick5 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5 }
+define_pick_structs! { Pick6 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6 }
+define_pick_structs! { Pick7 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7 }
+define_pick_structs! { Pick8 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8 }
+define_pick_structs! { Pick9 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9 }
+define_pick_structs! { Pick10 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9, T10 val_10 }
+define_pick_structs! { Pick11 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9, T10 val_10, T11 val_11 }
+define_pick_structs! { Pick12 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9, T10 val_10, T11 val_11, T12 val_12 }
+impl_pick_structs! { Pick1 Pick2 val_2 T1 val_1 }
+impl_pick_structs! { Pick2 Pick3 val_3 T1 val_1, T2 val_2 }
+impl_pick_structs! { Pick3 Pick4 val_4 T1 val_1, T2 val_2, T3 val_3 }
+impl_pick_structs! { Pick4 Pick5 val_5 T1 val_1, T2 val_2, T3 val_3, T4 val_4 }
+impl_pick_structs! { Pick5 Pick6 val_6 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5 }
+impl_pick_structs! { Pick6 Pick7 val_7 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6 }
+impl_pick_structs! { Pick7 Pick8 val_8 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7 }
+impl_pick_structs! { Pick8 Pick9 val_9 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8 }
+impl_pick_structs! { Pick9 Pick10 val_10 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9 }
+impl_pick_structs! { Pick10 Pick11 val_11 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9, T10 val_10 }
+impl_pick_structs! { Pick11 Pick12 val_12 T1 val_1, T2 val_2, T3 val_3, T4 val_4, T5 val_5, T6 val_6, T7 val_7, T8 val_8, T9 val_9, T10 val_10, T11 val_11 }