Actually, the message format is LLSD notation not python (d'oh)

lib/classes/llsd/LLSDArray.ts

@@ -0,0 +1,53 @@
+import { LLSDTokenGenerator } from './LLSDTokenGenerator';
+import { LLSDTokenType } from './LLSDTokenType';
+import { LLSDNotationParser } from './LLSDNotationParser';
+import { LLSDType } from './LLSDType';
+
+export class LLSDArray
+{
+    public static parse(gen: LLSDTokenGenerator): LLSDType[]
+    {
+        const arr: LLSDType[] = [];
+        let value: LLSDType | undefined = undefined;
+        while (true)
+        {
+            const token = gen();
+            if (token === undefined)
+            {
+                throw new Error('Unexpected end of input in array');
+            }
+            switch (token.type)
+            {
+                case LLSDTokenType.WHITESPACE:
+                {
+                    continue;
+                }
+                case LLSDTokenType.ARRAY_END:
+                {
+                    if (value !== undefined)
+                    {
+                        arr.push(value);
+                    }
+                    return arr;
+                }
+                case LLSDTokenType.COMMA:
+                {
+                    if (value === undefined)
+                    {
+                        throw new Error('Expected value before comma');
+                    }
+                    arr.push(value);
+                    value = undefined;
+                    continue;
+                }
+            }
+
+            if (value !== undefined)
+            {
+                throw new Error('Comma or end brace expected');
+            }
+
+            value = LLSDNotationParser.parseValueToken(gen, token);
+        }
+    }
+}