BREAKING! Make IntervalDataType use IntervalUnit

Replace fieldsKw and precision properties with unit.

Author: nene

src/cst/DataType.ts

@@ -2,7 +2,7 @@ import { BaseNode, Empty, Keyword } from "./Base";
 import { ColumnConstraint } from "./Constraint";
 import { ColumnDefinition } from "./CreateTable";
 import { EntityName, Expr, Identifier, ListExpr, ParenExpr } from "./Expr";
-import { NumberLiteral } from "./Literal";
+import { IntervalUnit, IntervalUnitRange, NumberLiteral } from "./Literal";
 
 export type AllDataTypeNodes =
   | DataTypeName
@@ -74,14 +74,7 @@ export interface TimeDataType extends BaseNode {
 export interface IntervalDataType extends BaseNode {
   type: "interval_data_type";
   intervalKw: Keyword<"INTERVAL">;
-  fieldsKw?:
-    | Keyword<"YEAR" | "MONTH" | "DAY" | "HOUR" | "MINUTE" | "SECOND">
-    | [
-        Keyword<"YEAR" | "MONTH" | "DAY" | "HOUR" | "MINUTE" | "SECOND">,
-        Keyword<"TO">,
-        Keyword<"YEAR" | "MONTH" | "DAY" | "HOUR" | "MINUTE" | "SECOND">
-      ];
-  precision?: ParenExpr<Expr>;
+  unit?: IntervalUnit | IntervalUnitRange;
 }
 
 // BigQuery

src/parser.pegjs

@@ -7075,12 +7075,11 @@ time_data_type
   }
 
 interval_data_type
-  = kw:INTERVAL fieldsKw:(__ interval_unit_kw __ TO __ interval_unit_kw / __ interval_unit_kw)? precision:(__ paren$expr)? {
+  = kw:INTERVAL unit:(__ (interval_unit_range / interval_unit))? {
     return loc({
       type: "interval_data_type",
       intervalKw: read(kw),
-      fieldsKw: read(fieldsKw),
-      precision: read(precision),
+      unit: read(unit),
     });
   }
 

src/showNode/data_type.ts

@@ -10,8 +10,7 @@ export const dataTypeMap: FullTransformMap<string, AllDataTypeNodes> = {
   array_bounds: (node) => show(["[", node.bounds, "]"]),
   time_data_type: (node) =>
     show([node.timeKw, node.precision, node.timeZoneKw]),
-  interval_data_type: (node) =>
-    show([node.intervalKw, node.fieldsKw, node.precision]),
+  interval_data_type: (node) => show([node.intervalKw, node.unit]),
   generic_type_params: (node) => show(["<", node.params, ">"]),
   array_type_param: (node) => show([node.dataType, node.constraints]),
   struct_type_param: (node) =>