Chapter 11 The OCaml language

5 Constants

constant::= integer-literal
 ∣ int32-literal
 ∣ int64-literal
 ∣ nativeint-literal
 ∣ float-literal
 ∣ char-literal
 ∣ string-literal
 ∣ constr
 ∣ false
 ∣ true
 ∣ ()
 ∣ begin end
 ∣ []
 ∣ [||]
 ∣ `tag-name

See also the following language extension: extension literals.

The syntactic class of constants comprises literals from the four base types (integers, floating-point numbers, characters, character strings), the integer variants, and constant constructors from both normal and polymorphic variants, as well as the special constants false, true, (), [], and [||], which behave like constant constructors, and begin end, which is equivalent to ().