Start a filter parser

api/src/models/utils/filters.ts

@@ -0,0 +1,62 @@
+import { digit, float, int, noCharOf, type Parjser, string } from "parjs";
+import {
+	exactly,
+	many,
+	many1,
+	map,
+	or,
+	stringify,
+	then,
+	thenq,
+} from "parjs/combinators";
+
+export type Filter = {
+	[key: string]: any;
+};
+
+type Property = string;
+type Value =
+	| { type: "int"; value: number }
+	| { type: "float"; value: number }
+	| { type: "date"; value: string }
+	| { type: "string"; value: string };
+type Operator = "eq" | "ne" | "gt" | "ge" | "lt" | "le" | "has" | "in";
+type Expression =
+	| { type: "op"; operator: Operator; property: Property; value: Value }
+	| { type: "and"; first: Expression; second: Expression }
+	| { type: "or"; first: Expression; second: Expression }
+	| { type: "not"; expression: Expression };
+
+function t<T>(parser: Parjser<T>): Parjser<T> {
+	return parser.pipe(thenq(string(" ").pipe(many())));
+}
+
+const str = t(noCharOf(" ")).pipe(many1(), stringify()).expects("a string");
+const property = str.expects("a property");
+
+const intVal = t(int().pipe(map((i) => ({ type: "int" as const, value: i }))));
+const floatVal = t(
+	float().pipe(map((f) => ({ type: "float" as const, value: f }))),
+);
+const dateVal = t(
+	digit(10).pipe(
+		exactly(4),
+		thenq(string("-")),
+		then(
+			digit(10).pipe(exactly(2), thenq(string("-"))),
+			digit(10).pipe(exactly(2)),
+		),
+		map(([year, month, day]) => ({
+			type: "date" as const,
+			value: `${year}-${month}-${day}`,
+		})),
+	),
+);
+const strVal = t(str.pipe(map((s) => ({ type: "string" as const, value: s }))));
+const value = intVal
+	.pipe(or(floatVal, dateVal, strVal))
+	.expects("a valid value");
+
+const operator = null;
+
+export const parseFilter = (filter: string, config: Filter) => {};