Refactor: separate QryFunc name and args formatting

Closes #26 (closed)

src/query/fns/aggregate.rs

 //! Aggregate query functions (includes PromQL aggregation operators)
-use super::{basic_fn, QryFunc};
+use super::{basic_fn, qry_fn, QryFunc};
 use crate::{
     query::{
         ops::{
@@ -133,7 +133,7 @@ pub fn count_values<'a>(
     label: &'_ str,
     vec_expr: impl Operable + 'static,
 ) -> AggrFunc<'a, impl Fn(&mut fmt::Formatter) -> fmt::Result + '_> {
-    QryFunc::new(move |f| write!(f, r#"count_values("{label}", {vec_expr})"#)).into()
+    qry_fn!(count_values, r#""{label}", {vec_expr}"#).into()
 }
 
 /// The topk aggregate operator/function
@@ -142,7 +142,7 @@ pub fn topk<'a>(
     k: usize,
     vec_expr: impl Operable + 'static,
 ) -> AggrFunc<'a, impl Fn(&mut fmt::Formatter) -> fmt::Result> {
-    QryFunc::new(move |f| write!(f, "topk({k}, {vec_expr})")).into()
+    qry_fn!(topk, "{k}, {vec_expr}").into()
 }
 
 /// The bottomk aggregate operator/function
@@ -151,7 +151,7 @@ pub fn bottomk<'a>(
     k: usize,
     vec_expr: impl Operable + 'static,
 ) -> AggrFunc<'a, impl Fn(&mut fmt::Formatter) -> fmt::Result> {
-    QryFunc::new(move |f| write!(f, "bottomk({k}, {vec_expr})")).into()
+    qry_fn!(bottomk, "{k}, {vec_expr}").into()
 }
 
 /// The bottomk aggregate operator/function (phi value should always be >= 0 and <= 1)
@@ -160,7 +160,7 @@ pub fn quantile<'a>(
     phi: f32,
     vec_expr: impl Operable + 'static,
 ) -> AggrFunc<'a, impl Fn(&mut fmt::Formatter) -> fmt::Result> {
-    QryFunc::new(move |f| write!(f, "quantile({phi}, {vec_expr})")).into()
+    qry_fn!(quantile, "{phi}, {vec_expr}").into()
 }
 
 #[cfg(test)]
@@ -171,20 +171,14 @@ mod tests {
 
     #[test]
     fn by_mod() {
-        let agr = AggrFunc {
-            inner: QryFunc::new(|f| f.write_str("func(x)")),
-            mod_type: Default::default(),
-        };
+        let agr: AggrFunc<_> = qry_fn!(func, "x").into();
         let by_str = agr.by(["label", "label2"]).to_string();
         assert_eq!(by_str, "func(x) by (label,label2)");
     }
 
     #[test]
     fn without_mod() {
-        let agr = AggrFunc {
-            inner: QryFunc::new(|f| f.write_str("func(x)")),
-            mod_type: Default::default(),
-        };
+        let agr: AggrFunc<_> = qry_fn!(func, "x").into();
         let by_str = agr.without(["label", "label2"]).to_string();
         assert_eq!(by_str, "func(x) without (label,label2)");
     }