1\DOC op_arity 2 3\TYPE {op_arity : {Thy:string, Tyop:string} -> int option} 4 5\SYNOPSIS 6Return the arity of a type operator. 7 8\KEYWORDS 9signature, type operator. 10 11\DESCRIBE 12An invocation {op_arity{Tyop,Thy}} returns {NONE} if the given record 13does not identify a type operator in the current type signature. 14Otherwise, it returns {SOME n}, where {n} identifies the number 15of arguments the specified type operator takes. 16 17\FAILURE 18Never fails. 19 20\EXAMPLE 21{ 22- op_arity{Tyop="fun", Thy="min"}; 23> val it = SOME 2 : int option 24 25- op_arity{Tyop="foo", Thy="min"}; 26> val it = NONE : int option 27} 28 29 30\SEEALSO 31Type.decls. 32\ENDDOC 33