Stub out Idv parser

lib/idv.ts

@@ -0,0 +1,72 @@
+export type DistinguisherParser<T> = (distinguisher: string) => T;
+export type DocumentParser<T> = (document: string[]) => T;
+
+const LEADING_WHITESPACE = /^([ \t]+)/;
+const ENTRY = /^(.+?):\s*(.*)/;
+
+export class Idv {
+  collections: Record<string, undefined | [string, string[]][]> = {};
+
+  public static parse(input: string): Idv {
+    const lines = input.split("\n").map((line) => line.trimEnd());
+    return Idv.parseLines(lines);
+  }
+  static parseLines(input: string[]): Idv {
+    const idv = new Idv();
+    let currentDocument: string[] = [];
+
+    input.forEach((line) => {
+      const indent = LEADING_WHITESPACE.exec(line)?.[1];
+      if (indent) {
+        // TODO
+      } else if (line == "") {
+        // TODO
+      } else if (line[0] == "#") {
+        // skip
+      } else {
+        const matches = ENTRY.exec(line);
+        if (matches) {
+          const [, collection, distinguisher] = matches;
+
+          if (idv.collections[collection] == undefined) {
+            idv.collections[collection] = [];
+          }
+
+          currentDocument = [];
+          idv.collections[collection].push([distinguisher, currentDocument]);
+        } else {
+          throw new Error("Failed to parse a property");
+        }
+      }
+    });
+
+    return idv;
+  }
+
+  public getProperty<T>(
+    name: string,
+    parseDistinguisher: DistinguisherParser<T>,
+    parseDocument: DocumentParser<T>
+  ): T | null {
+    const firstEntry = this.collections[name]?.[0];
+    return firstEntry && firstEntry[1].length > 0
+      ? parseDocument(firstEntry[1])
+      : firstEntry?.[0]
+      ? parseDistinguisher(firstEntry[0])
+      : null;
+  }
+
+  public getList<T>(
+    name: string,
+    parseDistinguisher: DistinguisherParser<T>,
+    parseDocument: DocumentParser<T>
+  ): T[] {
+    return (this.collections[name] ?? []).map(([distinguisher, document]) =>
+      document.length > 0
+        ? parseDocument(document)
+        : parseDistinguisher(distinguisher)
+    );
+  }
+}
+
+export const StringFromDocument = (lines: string[]) => lines.join("\n");