.TH LISTS 2.SH NAMElists: allsat, anysat, append, combine, concat, delete, filter, ismember, last, map, pair, partition, rev, unpair\- list operations.SH SYNOPSIS.EXinclude "lists.m"lists := load Lists Lists->PATH; append:    fn[T](l: list of T, x: T): list of T;combine:   fn[T](l1: list of T, l2: list of T): list of T;concat:    fn[T](l1: list of T, l2: list of T): list of T;delete:    fn[T](x: T, l: list of T): list of T             for { T => eq:  fn(a, b: T): int; };ismember:  fn[T](x: T, l: list of T): int             for { T =>  eq: fn(a, b: T): int; };last:      fn[T](l: list of T): T;pair:      fn[T1, T2](l1: list of T1, l2: list of T2):             list of (T1, T2);reverse:   fn[T](l: list of T): list of T;unpair:    fn[T1, T2](l: list of (T1, T2)):             (list of T1, list of T2); allsat:    fn[T](p: ref fn(x: T): int, l: list of T): int;anysat:    fn[T](p: ref fn(x: T): int, l: list of T): int;filter:    fn[T](p: ref fn(x: T): int, l: list of T): list of T;map:       fn[T](f: ref fn(x: T): T, l: list of T): list of T;partition: fn[T](p: ref fn(x: T): int, l: list of T):             (list of T, list of T);.EE.SH DESCRIPTIONThe module provides operations on lists of type.IR T ,which may be any reference type, or.BR string .Reference types are.BR array ,.BR chan ,.BR list ,.BR module ,and.BI ref "adt".None of the operations change their parameter lists: they always return a new list..PPFirst, there is a group of common list operations..PP.B Appendreturns a new list with the elements of.I lfollowed by the element.IR x ..PP.B Combinereturns a new list that has the elements of both.I l1and.I l2in no defined order..PP.B Concatreturns a new list that has the elements of.I l1followed by the elements of.IR l2 ..PP.B Deletereturns a new list in which the first element of.I lthat is equal to.I xhas been removed (all others remain)..I Xmust be an adt reference type.I Twith an operation.IB T .eqthat returns true (non-zero) if two values of type.I Tare considered equal..PP.B Ismemberreturns 1 ifthere is an element of.I lthat is equal to.IR x ..PP.B Lastreturns the value of the element at the end of list.IR l .A run-time error occurs if.I lis nil..PP.B Pairtakes two lists.I l1and.IR l2 ,and returns a new list of tuples.BI ( v1,\ v2 )in which each element of.I l1has been paired with the corresponding element of.IR l2 .A run-time error occurs if the lists are not equal in length..PP.B Reversereturns a new list containing the elements of.I lin reverse order..PP.B Unpairtakes a list of tuples.BI ( v1,\ v2 )and returns a tuple of lists.BI ( l1,\ l2 )where.I l1contains the first element of each tuple, and.I l2contains the second element of each tuple..PPA second group of operations applies a function.I for a Boolean predicate.I pto each element of a list.IR l ,returning a transformed list or a Boolean value.A predicate.I pmust return non-zero if its parameter value satisfies its condition, and must return zero if it does not..PP.B Allsatreturns 1 if all elements of.I lsatisfy.IR p ,and returns 0 otherwise..PP.B Anysatreturns 1 if any element of.I lsatisfies.IR p ,and returns 0 otherwise..PP.B Filterreturns a new list containing only the elements of.I lthat satisfy.IR p ..PP.B Mapreturns a new list in which each element of.I lhas been transformed by.I f(ie, if.I lis.IB e0 :: e1 ::  ...then the result is.IB f(e0) :: f(e1) :: ... )..PP.B Partitionreturns a tuple of lists.BI ( l1,\ l2 )of lists where.I l1contains all elements of.I lthat satisfy.I pand.I l2contains all elements of.I lthat do not satisfy.IR p ..SH SOURCE.B /appl/lib/lists.b.SH BUGSThe current implementation of polymorphism is limited to reference types and strings,which in turn limits use of this module.