add group number syntax to pest ast

ast/src/leo.pest

@@ -234,7 +234,8 @@ value_boolean = { "true" | "false" }
 value_field = ${ value_number ~ type_field }
 
 // Declared in values/group_value.rs
-value_group = ${ group_tuple ~ type_group }
+value_group = ${ group_single_or_tuple ~ type_group }
+group_single_or_tuple = {value_number | group_tuple}
 group_tuple = !{"(" ~ group_coordinate ~ "," ~ group_coordinate ~ ")"}
 
 // Declared in values/group_coordinate.rs

ast/src/values/group_value.rs

@@ -14,7 +14,12 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{ast::Rule, types::GroupType, values::GroupCoordinate, SpanDef};
+use crate::{
+    ast::Rule,
+    types::GroupType,
+    values::{GroupCoordinate, NumberValue},
+    SpanDef,
+};
 
 use pest::Span;
 use pest_ast::FromPest;
@@ -24,7 +29,7 @@ use std::fmt;
 #[derive(Clone, Debug, FromPest, PartialEq, Serialize)]
 #[pest_ast(rule(Rule::value_group))]
 pub struct GroupValue<'ast> {
-    pub value: GroupTuple<'ast>,
+    pub value: GroupRepresentation<'ast>,
     pub type_: GroupType,
     #[pest_ast(outer())]
     #[serde(with = "SpanDef")]
@@ -37,6 +42,22 @@ impl<'ast> fmt::Display for GroupValue<'ast> {
     }
 }
 
+#[derive(Clone, Debug, FromPest, PartialEq, Serialize)]
+#[pest_ast(rule(Rule::group_single_or_tuple))]
+pub enum GroupRepresentation<'ast> {
+    Single(NumberValue<'ast>),
+    Tuple(GroupTuple<'ast>),
+}
+
+impl<'ast> fmt::Display for GroupRepresentation<'ast> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            GroupRepresentation::Single(number) => write!(f, "{}", number),
+            GroupRepresentation::Tuple(tuple) => write!(f, "{}", tuple),
+        }
+    }
+}
+
 #[derive(Clone, Debug, FromPest, PartialEq, Serialize)]
 #[pest_ast(rule(Rule::group_tuple))]
 pub struct GroupTuple<'ast> {