/**
* Copyright 2024 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { GenkitError } from '@genkit-ai/core';
import { extractItems } from '../extract';
import type { Formatter } from './types';
export const arrayFormatter: Formatter<unknown[], unknown[]> = {
name: 'array',
config: {
contentType: 'application/json',
constrained: true,
},
handler: (schema) => {
if (schema && schema.type !== 'array') {
throw new GenkitError({
status: 'INVALID_ARGUMENT',
message: `Must supply an 'array' schema type when using the 'items' parser format.`,
});
}
let instructions: string | undefined;
if (schema) {
instructions = `Output should be a JSON array conforming to the following schema:
\`\`\`
${JSON.stringify(schema)}
\`\`\`
`;
}
return {
parseChunk: (chunk) => {
// first, determine the cursor position from the previous chunks
const cursor = chunk.previousChunks?.length
? extractItems(chunk.previousText).cursor
: 0;
// then, extract the items starting at that cursor
const { items } = extractItems(chunk.accumulatedText, cursor);
return items;
},
parseMessage: (message) => {
const { items } = extractItems(message.text, 0);
return items;
},
instructions,
};
},
};