EdnProvide

input/src/edn_command.rs

@@ -0,0 +1,34 @@
+use crate::*;
+use EdnItem::*;
+
+#[macro_export] macro_rules! edn_command {
+    ($Command:ty : |$state:ident:$State:ty| {
+        $(($key:literal [$($arg:ident : $type:ty),*] $command:expr))*
+    }) => {
+        impl EdnCommand<$State> for $Command {
+            fn from_edn <'a> ($state: &$State, head: &EdnItem<&str>, tail: &'a [EdnItem<String>]) -> Self {
+                match (head, tail) {
+                    $((EdnItem::Key($key), [$($arg),*]) => {
+                        $(let $arg: $type = EdnProvide::<$type>::get_or_fail($state, $arg);)*
+                        $command
+                    },)*
+                    _ => panic!("no such command")
+                }
+            }
+        }
+    }
+}
+
+/// Turns an EDN symbol sequence into a command enum variant.
+pub trait EdnCommand<C>: Command<C> {
+    fn from_edn <'a> (state: &C, head: &EdnItem<&str>, tail: &'a [EdnItem<String>]) -> Self;
+    fn get_isize (state: &C, item: &EdnItem<&str>) -> Option<isize> {
+        None
+    }
+    fn get_usize (state: &C, item: &EdnItem<&str>) -> Option<usize> {
+        None
+    }
+    fn get_bool  (state: &C, item: &EdnItem<&str>) -> Option<usize> {
+        None
+    }
+}