11.3.53 current_op/3   ISO

Synopsis

current_op(?Precedence, ?Type, ?Name)

Succeeds when the atom Name is currently an operator of type Type and precedence Precedence.

Arguments

Precedence

integer, in the range 1-1200

Type

one of [xfx, xfy, yfx, fx, fy, xf, yf]

Name

atom

Description

None of the arguments need be instantiated at the time of the call; that is, this predicate can be used to find the precedence or type of an operator or to backtrack through all operators.

To add or remove an operator, use op/3.

Exceptions

type_error

Name not an atom or Type not an atom or Precedence not an integer.

domain_error

Precedence not between 1-1200, or Type not one of listed atoms.

Examples

See Also

op/3, ref-syn-ops.