Meanings
- uncountabletype theorycomputerIn a functional language, inference of a polymorphic type only for syntactic values (values that can be evaluated at compile time) to ensure that a program is type-safe.
It has been found empirically that eta expansion usually suffices for dealing with the value restriction.
2007, Geoffrey Smith, Notes on SML97's Value Restriction1 more example
A typical example is an expression returning always the empty list. It should be given the polymorphic type α list, but this is not possible under the value restriction if the expression has to be evaluated.
2004, Jacques Garrigue, Relaxing the Value Restriction
Cite this entry
value restriction. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/value%20restriction
“value restriction.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/value%20restriction. Accessed November 2, 2026.
WatkinsX Dictionary, s.v. “value restriction,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/value%20restriction.
Source: value restriction on Wiktionary, CC BY-SA 4.0.