erlang module Erlang Programming - Lecture 8

Transcription

1 erlang module Erlang Programming - Lecture 8 Saurabh Barjatiya Rekall Software Pvt. Ltd. 29 June, 2014

2 Contents erlang module Auto-imported Built-In Functions (BIFs) BIFs allowed in guard test 1 erlang module Auto-imported Built-In Functions (BIFs) BIFs allowed in guard test 2 of Erlang module

3 Auto-imported Built-In Functions (BIFs) BIFs allowed in guard test Auto-imported Built-In Functions (BIFs) In man page of erlang module (erl -man erlang) auto-imported BIFs are shown without erlang: prefix. These functions can be called without explicitly stating module name erlang. For example: try-catch syntax 1> abs(1). 1 2> abs(-1). 1 3>

4 BIFs allowed in guard test Auto-imported Built-In Functions (BIFs) BIFs allowed in guard test In man page of erlang module (erl -man erlang) BIFs allowed in guard tests have description Allowed in guard tests.. Only these functions can be called in guard tests as they are guaranteed to finish in limited amount of time. try-catch syntax 1> case 1 of 1 when abs(1)>2 -> 1; 1 when abs(3)>2 -> 3 end. 3 2>

5 Contents erlang module of Erlang module 1 erlang module Auto-imported Built-In Functions (BIFs) BIFs allowed in guard test 2 of Erlang module

6 of Erlang module of Erlang module - 01 of Erlang module are: apply(fun, Args) -> term() apply(module, Function, Args) -> term() binary to list(binary) -> [char()] binary to term(binary) -> term() date() -> Date element(n, Tuple) -> term() error(reason) error(reason, Args) exit(reason) exit(pid, Reason) -> true

7 of Erlang module of Erlang module - 02 float to list(float) -> string() erlang:get cookie() -> Cookie nocookie erlang:get stacktrace() -> [Module, Function, Arity Args] hd(list) -> term() integer to list(integer) -> string() integer to list(integer, Base) -> string() is atom(term) -> boolean() is binary(term) -> boolean() is boolean(term) -> boolean() is float(term) -> boolean()

8 of Erlang module of Erlang module - 03 is function(term) -> boolean() is function(term, Arity) -> boolean() is integer(term) -> boolean() is list(term) -> boolean() is number(term) -> boolean() is pid(term) -> boolean() is process alive(pid) -> boolean() is record(term, RecordTag) -> boolean() is reference(term) -> boolean() is tuple(term) -> boolean()

9 of Erlang module of Erlang module - 04 length(list) -> integer() >= 0 link(pid) -> true list to binary(iolist) -> binary() list to float(string) -> float() list to integer(string) -> integer() list to integer(string, Base) -> integer() erlang:localtime() -> DateTime erlang:localtime to universaltime(localtime :: Date1, Time1) -> Date2, Time2 make ref() -> reference() monitor(type, Item) -> MonitorRef

10 of Erlang module of Erlang module - 05 monitor node(node, Flag) -> true node() -> Node node(arg) -> Node nodes() -> Nodes now() -> timestamp() open port(portname, PortSettings) -> port() port close(port) -> true port command(port, Data) -> true port connect(port, Pid) -> true process flag(flag, Value) -> OldValue

11 of Erlang module of Erlang module - 06 register(regname, Pid Port) -> true round(number) -> integer() self() -> pid() erlang:set cookie(node, Cookie) -> true setelement(index, Tuple1, Value) -> Tuple2 size(item) -> integer() >= 0 spawn(fun) -> pid() spawn(node, Fun) -> pid() spawn(module, Function, Args) -> pid() spawn(node, Module, Function, Args) -> pid()

12 of Erlang module of Erlang module - 07 spawn link(fun) -> pid() spawn link(node, Fun) -> pid() spawn link(module, Function, Args) -> pid() spawn link(node, Module, Function, Args) -> pid() spawn monitor(fun) -> pid(), reference() spawn monitor(module, Function, Args) -> pid(), reference() term to binary(term) -> ext binary() throw(any) time() -> Hour, Minute, Second tl(list1) -> List2

13 of Erlang module of Erlang module - 08 trunc(number) -> integer() tuple size(tuple) -> integer() >= 0 erlang:universaltime() -> DateTime erlang:universaltime to localtime(date1, Time1) -> Date2, Time2 unlink(id) -> true unregister(regname) -> true whereis(regname) -> pid() port() undefined