Sentinel value
A sentinel value is a distinguished value interpreted as signaling a special condition, such as a boundary, termination, absence, or exceptional result.
Clojure: The Essential Reference
A sentinel value is a distinguished value whose agreed meaning signals a condition such as termination or absence of further input.
- How it is used
- Uses a mutually agreed value to terminate daemon-like processing when missing input alone cannot end computation.
- How deep it goes
- Defines the contract and works through a queued concurrent example, but does not develop a broader sentinel design taxonomy.
- Examples
- Uses a unique Object, LinkedBlockingQueue events, a worker thread, and hash-printing before termination.
- What you can do after
- Build it from scratch by coordinating producers and consumers around a unique termination object checked with identical?.
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Financial AI in Practice
A designated data value used to represent a special condition, such as missing or inapplicable information, rather than a valid measurement.
- How it is used
- Handles placeholder codes in credit data to reduce distortion and support fair, stable modeling.
- How deep it goes
- Gives steps for identifying, validating, binning, and documenting codes, but does not specify a coding implementation.
- Examples
- Uses -9999 for no bureau record and 8888 for unknown employment type as example codes.
- What you can do after
- Diagnose/debug credit-data skew by identifying sentinel codes, separating their bin, and documenting default-rate effects.
Related concepts
- error codeincludes · An error code is a symbolic or numeric value that indicates or identifies an error or failure condition.
- get methodproduced by · A lookup operation on a mapping or associative collection that returns the value associated with a key or index, often with a null-like result or supplied default when no entry exists.
- optioncontrasts with · An option type is a type that explicitly represents either a value of a specified type or the absence of a value.
- closed channelalternative to · A closed channel is a Go channel that accepts no further sends while allowing receives to complete, including delivery of buffered values.
- field maskused by · A field mask is an API specification that identifies which fields of a resource or response should be selected or modified.
- iteratorcontrasts with · An iterator is an object or abstraction that provides successive values from a sequence or data source through a traversal protocol.
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