erl_pp(3erl) [linux man page]

erl_pp(3erl)						     Erlang Module Definition						      erl_pp(3erl)

NAME

       erl_pp - The Erlang Pretty Printer

DESCRIPTION

       The functions in this module are used to generate aesthetically attractive representations of abstract forms, which are suitable for print-
       ing. All functions return (possibly deep) lists of characters and generate an error if the form is wrong.

       All functions can have an optional argument which specifies a hook that is called if an attempt is made to print an unknown form.

EXPORTS

       form(Form) -> DeepCharList
       form(Form, HookFunction) -> DeepCharList

	      Types  Form = term()
		     HookFunction = see separate description below.
		     DeepCharList = [char()|DeepCharList]

	      Pretty prints a Form which is an abstract form of a type which is returned by erl_parse:parse_form .

       attribute(Attribute) -> DeepCharList
       attribute(Attribute, HookFunction) -> DeepCharList

	      Types  Attribute = term()
		     HookFunction = see separate description below.
		     DeepCharList = [char()|DeepCharList]

	      The same as form , but only for the attribute Attribute .

       function(Function) -> DeepCharList
       function(Function, HookFunction) -> DeepCharList

	      Types  Function = term()
		     HookFunction = see separate description below.
		     DeepCharList = [char()|DeepCharList]

	      The same as form , but only for the function Function .

       guard(Guard) -> DeepCharList
       guard(Guard, HookFunction) -> DeepCharList

	      Types  Form = term()
		     HookFunction = see separate description below.
		     DeepCharList = [char()|DeepCharList]

	      The same as form , but only for the guard test Guard .

       exprs(Expressions) -> DeepCharList
       exprs(Expressions, HookFunction) -> DeepCharList
       exprs(Expressions, Indent, HookFunction) -> DeepCharList

	      Types  Expressions = term()
		     HookFunction = see separate description below.
		     Indent = integer()
		     DeepCharList = [char()|DeepCharList]

	      The same as form , but only for the sequence of expressions in Expressions .

       expr(Expression) -> DeepCharList
       expr(Expression, HookFunction) -> DeepCharList
       expr(Expression, Indent, HookFunction) -> DeepCharList
       expr(Expression, Indent, Precedence, HookFunction) ->-> DeepCharList

	      Types  Expression = term()
		     HookFunction = see separate description below.
		     Indent = integer()
		     Precedence =
		     DeepCharList = [char()|DeepCharList]

	      This function prints one expression. It is useful for implementing hooks (see below).

UNKNOWN EXPRESSION HOOKS

       The optional argument HookFunction , shown in the functions described above, defines a function which is called when an unknown form occurs
       where there should be a valid expression. It can have the following formats:

	 Function :
	   The hook function is called by:

	 Function(Expr,
		  CurrentIndentation,
		  CurrentPrecedence,
		  HookFunction)

	 none :
	   There is no hook function

       The called hook function should return a (possibly deep) list of characters. expr/4 is useful in a hook.

       If CurrentIndentation is negative, there will be no line breaks and only a space is used as a separator.

BUGS

       It should be possible to have hook functions for unknown forms at places other than expressions.

SEE ALSO

       io(3erl) , erl_parse(3erl) , erl_eval(3erl)

Ericsson AB							   stdlib 1.17.3						      erl_pp(3erl)

Check Out this Related Man Page

sets(3erl)						     Erlang Module Definition							sets(3erl)

NAME

       sets - Functions for Set Manipulation

DESCRIPTION

       Sets are collections of elements with no duplicate elements. The representation of a set is not defined.

       This  module provides exactly the same interface as the module ordsets but with a defined representation. One difference is that while this
       module considers two elements as different if they do not match ( =:= ), ordsets considers two elements as different if and only if they do
       not compare equal ( == ).

DATA TYPES

       set()
	 as returned by new/0

EXPORTS

       new() -> Set

	      Types  Set = set()

	      Returns a new empty set.

       is_set(Set) -> bool()

	      Types  Set = term()

	      Returns true if Set is a set of elements, otherwise false .

       size(Set) -> int()

	      Types  Set = term()

	      Returns the number of elements in Set .

       to_list(Set) -> List

	      Types  Set = set()
		     List = [term()]

	      Returns the elements of Set as a list.

       from_list(List) -> Set

	      Types  List = [term()]
		     Set = set()

	      Returns an set of the elements in List .

       is_element(Element, Set) -> bool()

	      Types  Element = term()
		     Set = set()

	      Returns true if Element is an element of Set , otherwise false .

       add_element(Element, Set1) -> Set2

	      Types  Element = term()
		     Set1 = Set2 = set()

	      Returns a new set formed from Set1 with Element inserted.

       del_element(Element, Set1) -> Set2

	      Types  Element = term()
		     Set1 = Set2 = set()

	      Returns Set1 , but with Element removed.

       union(Set1, Set2) -> Set3

	      Types  Set1 = Set2 = Set3 = set()

	      Returns the merged (union) set of Set1 and Set2 .

       union(SetList) -> Set

	      Types  SetList = [set()]
		     Set = set()

	      Returns the merged (union) set of the list of sets.

       intersection(Set1, Set2) -> Set3

	      Types  Set1 = Set2 = Set3 = set()

	      Returns the intersection of Set1 and Set2 .

       intersection(SetList) -> Set

	      Types  SetList = [set()]
		     Set = set()

	      Returns the intersection of the non-empty list of sets.

       is_disjoint(Set1, Set2) -> bool()

	      Types  Set1 = Set2 = set()

	      Returns true if Set1 and Set2 are disjoint (have no elements in common), and false otherwise.

       subtract(Set1, Set2) -> Set3

	      Types  Set1 = Set2 = Set3 = set()

	      Returns only the elements of Set1 which are not also elements of Set2 .

       is_subset(Set1, Set2) -> bool()

	      Types  Set1 = Set2 = set()

	      Returns true when every element of Set 1 is also a member of Set2 , otherwise false .

       fold(Function, Acc0, Set) -> Acc1

	      Types  Function = fun (E, AccIn) -> AccOut
		     Acc0 = Acc1 = AccIn = AccOut = term()
		     Set = set()

	      Fold Function over every element in Set returning the final value of the accumulator.

       filter(Pred, Set1) -> Set2

	      Types  Pred = fun (E) -> bool()
		     Set1 = Set2 = set()

	      Filter elements in Set1 with boolean function Fun .

SEE ALSO

       ordsets(3erl) , gb_sets(3erl)

Ericsson AB							   stdlib 1.17.3							sets(3erl)

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erl_pp(3erl) [linux man page]

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