Improve arg parsing

crates/pile-value/src/extract/traits.rs

@@ -10,6 +10,7 @@ pub trait ObjectExtractor: Send + Sync {
 	async fn field(
 		&self,
 		name: &pile_config::Label,
+		args: Option<&str>,
 	) -> Result<Option<crate::value::PileValue>, std::io::Error>;
 
 	/// Return all fields in this extractor.
@@ -22,7 +23,7 @@ pub trait ObjectExtractor: Send + Sync {
 		let keys = self.fields().await?;
 		let mut map = serde_json::Map::new();
 		for k in &keys {
-			let v = match self.field(k).await? {
+			let v = match self.field(k, None).await? {
 				Some(x) => x,
 				None => continue,
 			};