The HashConsBool structure
Author: John Reppy
Keywords: Standard ML, SML, SML/NJ Library

The SML of NJ Library
The `HashConsBool` structure

The `HashConsBool` structure embeds the `bool` type as a hash-consed object.

## Synopsis

    structure HashConsBool

## Interface

    type hash_key = bool
    type obj = hash_key HashCons.obj

    val mk : hash_key -> obj

    val hcFalse : obj
    val hcTrue : obj

## Description

`type hash_key = bool`

  The ground type being hashed.

`type obj = hash_key HashCons.obj`

  The type of hash-consed booleans.

`val mk : hash_key -> obj`

  `mk b` converts the boolean `b` to a hash-consed object.

`val hcFalse : obj`

  the hash-consed representation of `false`.

`val hcTrue : obj`

  the hash-consed representation of `true`.

## See Also

`HashCons`, The HashCons Library

SML/NJ Version 110.99.9 (November 4, 2025)
Last updated 2025-11-04 15:48:25 UTC