parse indented documents

debug/idv.ts

@@ -16,7 +16,11 @@ Uid: 0
 Shell: tclsh
 Group: users
 Group: sudo
-    `
+Banner:
+  +------------------+
+  |Welcome to Debian!|
+  +------------------+
+#`
   );
 
   const pre = h("pre");

lib/idv.ts

@@ -13,14 +13,30 @@ export class Idv {
   }
   static parseLines(input: string[]): Idv {
     const idv = new Idv();
-    let currentDocument: string[] = [];
+    let currentDocument: string[] | undefined = undefined;
+    let currentIndent: string | undefined = undefined;
+    let bufferedBlankLines: string[] = [];
 
     input.forEach((line) => {
       const indent = LEADING_WHITESPACE.exec(line)?.[1];
       if (indent) {
-        // TODO
+        if (currentDocument == undefined) {
+          throw new Error("Indented document found before an entry");
+        }
+        if (currentIndent == undefined) {
+          currentIndent = indent;
+        }
+        if (line.startsWith(currentIndent)) {
+          currentDocument.push(...bufferedBlankLines);
+          bufferedBlankLines = [];
+          currentDocument.push(line.substring(currentIndent.length));
+        } else {
+          throw new Error(
+            "Inconsistent indentation- line indented less than the first line of its document"
+          );
+        }
       } else if (line == "") {
-        // TODO
+        bufferedBlankLines.push("");
       } else if (line[0] == "#") {
         // skip
       } else {
@@ -33,6 +49,7 @@ export class Idv {
           }
 
           currentDocument = [];
+          currentIndent = undefined;
           idv.collections[collection].push([distinguisher, currentDocument]);
         } else {
           throw new Error("Failed to parse a property");
@@ -47,13 +64,14 @@ export class Idv {
     name: string,
     parseDistinguisher: DistinguisherParser<T>,
     parseDocument: DocumentParser<T>
-  ): T | null {
+  ): T | undefined {
     const firstEntry = this.collections[name]?.[0];
-    return firstEntry && firstEntry[1].length > 0
+    return (
-      ? parseDocument(firstEntry[1])
+      firstEntry &&
-      : firstEntry?.[0]
+      (firstEntry[1].length > 0
-      ? parseDistinguisher(firstEntry[0])
+        ? parseDocument(firstEntry[1])
-      : null;
+        : parseDistinguisher(firstEntry[0]))
+    );
   }
 
   public getList<T>(