feat: Add more support for patterns and conditional match

src/cmd.rs

@@ -64,7 +64,10 @@ enum LogicArg {
 impl Parse for LogicArg {
     fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
         if input.peek(Token![for]) {
-            if input.peek3(Token![in]) {
+            let pat_fork = input.fork();
+            _ = pat_fork.parse::<Token![for]>()?;
+
+            if pat_fork.call(syn::Pat::parse_single).is_ok() && pat_fork.peek(Token![in]) {
                 input.parse().map(Self::ForIn)
             } else {
                 input.parse().map(Self::ForIter)
@@ -263,28 +266,54 @@ impl ToTokens for Match {
 
 struct MatchArm {
     pattern: syn::Pat,
+    if_expr: Option<Value>,
     args: Arguments,
 }
 
 impl Parse for MatchArm {
     fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
         let pattern = input.call(syn::Pat::parse_multi)?;
+        let if_expr = if input.peek(Token![if]) {
+            _ = input.parse::<Token![if]>()?;
+            Some(input.parse()?)
+        } else {
+            None
+        };
         _ = input.parse::<Token![=>]>()?;
         let args = input.parse()?;
 
-        Ok(Self { pattern, args })
+        Ok(Self {
+            pattern,
+            if_expr,
+            args,
+        })
     }
 }
 
 impl ToTokens for MatchArm {
     fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
-        let Self { pattern, args } = self;
+        let Self {
+            pattern,
+            if_expr,
+            args,
+        } = self;
 
-        tokens.extend(quote! {
-            #pattern => {
-                #args
-            }
-        });
+        tokens.extend(if_expr.as_ref().map_or_else(
+            || {
+                quote! {
+                    #pattern => {
+                        #args
+                    }
+                }
+            },
+            |if_expr| {
+                quote! {
+                    #pattern if #if_expr => {
+                        #args
+                    }
+                }
+            },
+        ));
     }
 }