Copyright	(c) 2025 Tushar Adhatrao
License	MIT
Maintainer	Tushar Adhatrao <tusharadhatrao@gmail.com>
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

Langchain.OutputParser.Core

Contents

Typeclass
Parsers

Description

This module provides the core types and instances for output parsers in the Langchain Haskell port. Output parsers are used to transform the raw output from language models into structured data formats, making it easier to work with the results in downstream applications.

The OutputParser typeclass defines the interface for parsing model output into specific types, and this module provides instances for common data structures such as booleans, lists, and JSON objects.

For more information on output parsers in the original Langchain library, see: https:/python.langchain.comdocsconceptsoutput_parsers/

Synopsis

class OutputParser a where
- parse :: Text -> Either String a
newtype CommaSeparatedList = CommaSeparatedList [Text]
newtype FromJSON a => JSONOutputStructure a = JSONOutputStructure {
- jsonValue :: a
}
newtype NumberSeparatedList = NumberSeparatedList [Text]

Typeclass

class OutputParser a where Source #

Typeclass for parsing output from language models into specific types. Instances of this class define how to convert a Text output into a value of type a.

Methods

parse :: Text -> Either String a Source #

Parse the given text into a value of type a. Returns Left with an error message if parsing fails, or Right with the parsed value.

Instances

Instances details

OutputParser ReactAgentOutputParser Source #
Instance details Defined in Langchain.Agents.React Methods parse :: Text -> Either String ReactAgentOutputParser Source #
OutputParser CommaSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String CommaSeparatedList Source #
OutputParser NumberSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String NumberSeparatedList Source #
OutputParser Bool Source #
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String Bool Source #
FromJSON a => OutputParser (JSONOutputStructure a) Source #	Instance for parsing JSON into any type that implements FromJSON.
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String (JSONOutputStructure a) Source #

Parsers

newtype CommaSeparatedList Source #

Represents a list of text items separated by commas.

Constructors

CommaSeparatedList [Text]

Instances

Instances details

Show CommaSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods showsPrec :: Int -> CommaSeparatedList -> ShowS # show :: CommaSeparatedList -> String # showList :: [CommaSeparatedList] -> ShowS #
Eq CommaSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods (==) :: CommaSeparatedList -> CommaSeparatedList -> Bool # (/=) :: CommaSeparatedList -> CommaSeparatedList -> Bool #
OutputParser CommaSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String CommaSeparatedList Source #

newtype FromJSON a => JSONOutputStructure a Source #

JSON parser wrapper Requires FromJSON instance for target type. Uses Aeson for parsing.

Example data type:

data Person = Person
  { name :: Text
  , age :: Int
  } deriving (Show, Eq, FromJSON)

Usage:

>>> parse "{\"name\": \"Bob\", \"age\": 25}" :: Either String (JSONOutputStructure Person)
Right (JSONOutputStructure {jsonValue = Person {name = "Bob", age = 25}})

Constructors

JSONOutputStructure
Fields jsonValue :: a

Instances

Instances details

FromJSON a => FromJSON (JSONOutputStructure a) Source #
Instance details Defined in Langchain.OutputParser.Core Methods parseJSON :: Value -> Parser (JSONOutputStructure a) # parseJSONList :: Value -> Parser [JSONOutputStructure a] # omittedField :: Maybe (JSONOutputStructure a) #
(FromJSON a, Show a) => Show (JSONOutputStructure a) Source #
Instance details Defined in Langchain.OutputParser.Core Methods showsPrec :: Int -> JSONOutputStructure a -> ShowS # show :: JSONOutputStructure a -> String # showList :: [JSONOutputStructure a] -> ShowS #
Eq a => Eq (JSONOutputStructure a) Source #
Instance details Defined in Langchain.OutputParser.Core Methods (==) :: JSONOutputStructure a -> JSONOutputStructure a -> Bool # (/=) :: JSONOutputStructure a -> JSONOutputStructure a -> Bool #
FromJSON a => OutputParser (JSONOutputStructure a) Source #	Instance for parsing JSON into any type that implements FromJSON.
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String (JSONOutputStructure a) Source #

newtype NumberSeparatedList Source #

Represents a list of text items separated by numbered prefixes, like "1. First item".

Constructors

NumberSeparatedList [Text]

Instances

Instances details

Show NumberSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods showsPrec :: Int -> NumberSeparatedList -> ShowS # show :: NumberSeparatedList -> String # showList :: [NumberSeparatedList] -> ShowS #
Eq NumberSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods (==) :: NumberSeparatedList -> NumberSeparatedList -> Bool # (/=) :: NumberSeparatedList -> NumberSeparatedList -> Bool #
OutputParser NumberSeparatedList Source #
Instance details Defined in Langchain.OutputParser.Core Methods parse :: Text -> Either String NumberSeparatedList Source #