Merge pull request #1115 from vinodkiran/FEATURE/output-parsers

New Feature - Output Parsers

Author: HenryHengZJ

packages/components/nodes/chains/LLMChain/LLMChain.ts

@@ -3,6 +3,10 @@ import { getBaseClasses, handleEscapeCharacters } from '../../../src/utils'
 import { LLMChain } from 'langchain/chains'
 import { BaseLanguageModel } from 'langchain/base_language'
 import { ConsoleCallbackHandler, CustomChainHandler, additionalCallbacks } from '../../../src/handler'
+import { BaseOutputParser } from 'langchain/schema/output_parser'
+import { formatResponse, injectOutputParser } from '../../outputparsers/OutputParserHelpers'
+import { BaseLLMOutputParser } from 'langchain/schema/output_parser'
+import { OutputFixingParser } from 'langchain/output_parsers'
 
 class LLMChain_Chains implements INode {
     label: string
@@ -15,11 +19,12 @@ class LLMChain_Chains implements INode {
     description: string
     inputs: INodeParams[]
     outputs: INodeOutputsValue[]
+    outputParser: BaseOutputParser
 
     constructor() {
         this.label = 'LLM Chain'
         this.name = 'llmChain'
-        this.version = 1.0
+        this.version = 3.0
         this.type = 'LLMChain'
         this.icon = 'chain.svg'
         this.category = 'Chains'
@@ -36,6 +41,12 @@ class LLMChain_Chains implements INode {
                 name: 'prompt',
                 type: 'BasePromptTemplate'
             },
+            {
+                label: 'Output Parser',
+                name: 'outputParser',
+                type: 'BaseLLMOutputParser',
+                optional: true
+            },
             {
                 label: 'Chain Name',
                 name: 'chainName',
@@ -63,12 +74,29 @@ class LLMChain_Chains implements INode {
         const prompt = nodeData.inputs?.prompt
         const output = nodeData.outputs?.output as string
         const promptValues = prompt.promptValues as ICommonObject
-
+        const llmOutputParser = nodeData.inputs?.outputParser as BaseOutputParser
+        this.outputParser = llmOutputParser
+        if (llmOutputParser) {
+            let autoFix = (llmOutputParser as any).autoFix
+            if (autoFix === true) {
+                this.outputParser = OutputFixingParser.fromLLM(model, llmOutputParser)
+            }
+        }
         if (output === this.name) {
-            const chain = new LLMChain({ llm: model, prompt, verbose: process.env.DEBUG === 'true' ? true : false })
+            const chain = new LLMChain({
+                llm: model,
+                outputParser: this.outputParser as BaseLLMOutputParser<string | object>,
+                prompt,
+                verbose: process.env.DEBUG === 'true'
+            })
             return chain
         } else if (output === 'outputPrediction') {
-            const chain = new LLMChain({ llm: model, prompt, verbose: process.env.DEBUG === 'true' ? true : false })
+            const chain = new LLMChain({
+                llm: model,
+                outputParser: this.outputParser as BaseLLMOutputParser<string | object>,
+                prompt,
+                verbose: process.env.DEBUG === 'true'
+            })
             const inputVariables = chain.prompt.inputVariables as string[] // ["product"]
             const res = await runPrediction(inputVariables, chain, input, promptValues, options, nodeData)
             // eslint-disable-next-line no-console
@@ -84,10 +112,15 @@ class LLMChain_Chains implements INode {
         }
     }
 
-    async run(nodeData: INodeData, input: string, options: ICommonObject): Promise<string> {
+    async run(nodeData: INodeData, input: string, options: ICommonObject): Promise<string | object> {
         const inputVariables = nodeData.instance.prompt.inputVariables as string[] // ["product"]
         const chain = nodeData.instance as LLMChain
-        const promptValues = nodeData.inputs?.prompt.promptValues as ICommonObject
+        let promptValues: ICommonObject | undefined = nodeData.inputs?.prompt.promptValues as ICommonObject
+        const outputParser = nodeData.inputs?.outputParser as BaseOutputParser
+        if (!this.outputParser && outputParser) {
+            this.outputParser = outputParser
+        }
+        promptValues = injectOutputParser(this.outputParser, chain, promptValues)
         const res = await runPrediction(inputVariables, chain, input, promptValues, options, nodeData)
         // eslint-disable-next-line no-console
         console.log('\x1b[93m\x1b[1m\n*****FINAL RESULT*****\n\x1b[0m\x1b[0m')
@@ -99,9 +132,9 @@ class LLMChain_Chains implements INode {
 
 const runPrediction = async (
     inputVariables: string[],
-    chain: LLMChain,
+    chain: LLMChain<string | object>,
     input: string,
-    promptValuesRaw: ICommonObject,
+    promptValuesRaw: ICommonObject | undefined,
     options: ICommonObject,
     nodeData: INodeData
 ) => {
@@ -135,10 +168,10 @@ const runPrediction = async (
             if (isStreaming) {
                 const handler = new CustomChainHandler(socketIO, socketIOClientId)
                 const res = await chain.call(options, [loggerHandler, handler, ...callbacks])
-                return res?.text
+                return formatResponse(res?.text)
             } else {
                 const res = await chain.call(options, [loggerHandler, ...callbacks])
-                return res?.text
+                return formatResponse(res?.text)
             }
         } else if (seen.length === 1) {
             // If one inputVariable is not specify, use input (user's question) as value
@@ -151,10 +184,10 @@ const runPrediction = async (
             if (isStreaming) {
                 const handler = new CustomChainHandler(socketIO, socketIOClientId)
                 const res = await chain.call(options, [loggerHandler, handler, ...callbacks])
-                return res?.text
+                return formatResponse(res?.text)
             } else {
                 const res = await chain.call(options, [loggerHandler, ...callbacks])
-                return res?.text
+                return formatResponse(res?.text)
             }
         } else {
             throw new Error(`Please provide Prompt Values for: ${seen.join(', ')}`)
@@ -163,10 +196,10 @@ const runPrediction = async (
         if (isStreaming) {
             const handler = new CustomChainHandler(socketIO, socketIOClientId)
             const res = await chain.run(input, [loggerHandler, handler, ...callbacks])
-            return res
+            return formatResponse(res)
         } else {
             const res = await chain.run(input, [loggerHandler, ...callbacks])
-            return res
+            return formatResponse(res)
         }
     }
 }

packages/components/nodes/outputparsers/CSVListOutputParser/CSVListOutputParser.ts

@@ -0,0 +1,52 @@
+import { getBaseClasses, INode, INodeData, INodeParams } from '../../../src'
+import { BaseOutputParser } from 'langchain/schema/output_parser'
+import { CommaSeparatedListOutputParser } from 'langchain/output_parsers'
+import { CATEGORY } from '../OutputParserHelpers'
+
+class CSVListOutputParser implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    inputs: INodeParams[]
+    credential: INodeParams
+
+    constructor() {
+        this.label = 'CSV Output Parser'
+        this.name = 'csvOutputParser'
+        this.version = 1.0
+        this.type = 'CSVListOutputParser'
+        this.description = 'Parse the output of an LLM call as a comma-separated list of values'
+        this.icon = 'csv.png'
+        this.category = CATEGORY
+        this.baseClasses = [this.type, ...getBaseClasses(BaseOutputParser)]
+        this.inputs = [
+            {
+                label: 'Autofix',
+                name: 'autofixParser',
+                type: 'boolean',
+                optional: true,
+                description: 'In the event that the first call fails, will make another call to the model to fix any errors.'
+            }
+        ]
+    }
+
+    async init(nodeData: INodeData): Promise<any> {
+        const autoFix = nodeData.inputs?.autofixParser as boolean
+
+        const commaSeparatedListOutputParser = new CommaSeparatedListOutputParser()
+        Object.defineProperty(commaSeparatedListOutputParser, 'autoFix', {
+            enumerable: true,
+            configurable: true,
+            writable: true,
+            value: autoFix
+        })
+        return commaSeparatedListOutputParser
+    }
+}
+
+module.exports = { nodeClass: CSVListOutputParser }

packages/components/nodes/outputparsers/CSVListOutputParser/csv.png

@@ -0,0 +1,71 @@
+import { getBaseClasses, INode, INodeData, INodeParams } from '../../../src'
+import { BaseOutputParser } from 'langchain/schema/output_parser'
+import { CustomListOutputParser as LangchainCustomListOutputParser } from 'langchain/output_parsers'
+import { CATEGORY } from '../OutputParserHelpers'
+
+class CustomListOutputParser implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    inputs: INodeParams[]
+    credential: INodeParams
+
+    constructor() {
+        this.label = 'Custom List Output Parser'
+        this.name = 'customListOutputParser'
+        this.version = 1.0
+        this.type = 'CustomListOutputParser'
+        this.description = 'Parse the output of an LLM call as a list of values.'
+        this.icon = 'list.png'
+        this.category = CATEGORY
+        this.baseClasses = [this.type, ...getBaseClasses(BaseOutputParser)]
+        this.inputs = [
+            {
+                label: 'Length',
+                name: 'length',
+                type: 'number',
+                default: 5,
+                step: 1,
+                description: 'Number of values to return'
+            },
+            {
+                label: 'Separator',
+                name: 'separator',
+                type: 'string',
+                description: 'Separator between values',
+                default: ','
+            },
+            {
+                label: 'Autofix',
+                name: 'autofixParser',
+                type: 'boolean',
+                optional: true,
+                description: 'In the event that the first call fails, will make another call to the model to fix any errors.'
+            }
+        ]
+    }
+
+    async init(nodeData: INodeData): Promise<any> {
+        const separator = nodeData.inputs?.separator as string
+        const lengthStr = nodeData.inputs?.length as string
+        const autoFix = nodeData.inputs?.autofixParser as boolean
+        let length = 5
+        if (lengthStr) length = parseInt(lengthStr, 10)
+
+        const parser = new LangchainCustomListOutputParser({ length: length, separator: separator })
+        Object.defineProperty(parser, 'autoFix', {
+            enumerable: true,
+            configurable: true,
+            writable: true,
+            value: autoFix
+        })
+        return parser
+    }
+}
+
+module.exports = { nodeClass: CustomListOutputParser }

packages/components/nodes/outputparsers/CustomListOutputParser/CustomListOutputParser.ts

@@ -0,0 +1,46 @@
+import { BaseOutputParser } from 'langchain/schema/output_parser'
+import { LLMChain } from 'langchain/chains'
+import { BaseLanguageModel } from 'langchain/base_language'
+import { ICommonObject } from '../../src'
+import { ChatPromptTemplate, FewShotPromptTemplate, PromptTemplate, SystemMessagePromptTemplate } from 'langchain/prompts'
+
+export const CATEGORY = 'Output Parsers'
+
+export const formatResponse = (response: string | object): string | object => {
+    if (typeof response === 'object') {
+        return { json: response }
+    }
+    return response
+}
+
+export const injectOutputParser = (
+    outputParser: BaseOutputParser<unknown>,
+    chain: LLMChain<string, BaseLanguageModel>,
+    promptValues: ICommonObject | undefined = undefined
+) => {
+    if (outputParser && chain.prompt) {
+        const formatInstructions = outputParser.getFormatInstructions()
+        if (chain.prompt instanceof PromptTemplate) {
+            let pt = chain.prompt
+            pt.template = pt.template + '\n{format_instructions}'
+            chain.prompt.partialVariables = { format_instructions: formatInstructions }
+        } else if (chain.prompt instanceof ChatPromptTemplate) {
+            let pt = chain.prompt
+            pt.promptMessages.forEach((msg) => {
+                if (msg instanceof SystemMessagePromptTemplate) {
+                    ;(msg.prompt as any).partialVariables = { format_instructions: outputParser.getFormatInstructions() }
+                    ;(msg.prompt as any).template = ((msg.prompt as any).template + '\n{format_instructions}') as string
+                }
+            })
+        } else if (chain.prompt instanceof FewShotPromptTemplate) {
+            chain.prompt.examplePrompt.partialVariables = { format_instructions: formatInstructions }
+            chain.prompt.examplePrompt.template = chain.prompt.examplePrompt.template + '\n{format_instructions}'
+        }
+
+        chain.prompt.inputVariables.push('format_instructions')
+        if (promptValues) {
+            promptValues = { ...promptValues, format_instructions: outputParser.getFormatInstructions() }
+        }
+    }
+    return promptValues
+}