STDLIB Release Notes

## 1 STDLIB Release Notes

This document describes the changes made to the STDLIB application.

### 1.1 STDLIB 1.15.5

#### 1.1.1 Fixed Bugs and Malfunctions

- A bug in the qlc module has been fixed: when merge joining two query handles the temporary file used for equivalence classes was not truncated properly which could result in poor performance.
  Own Id: OTP-7552
- The characters 16#C0 and 16#E0 ("A" and "a" with grave accent), were not properly converted by the string:to_lower/1 and string:to_upper/1 functions. (Thanks to Richard O'Keefe.)
  Own Id: OTP-7589
- The function pool:attach/1 now returns already_attached if the node is already attached, rather than allready_attached (sic!). (Thanks to Edwin Fine.)
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-7603
- The documentation for io:get_line/1,2 now mentions that the return value can also be {error,Reason}.
  Own Id: OTP-7604 Aux Id: seq11063

#### 1.1.2 Improvements and New Features

- The split function is now added to the re library. Exceptions and errors from both run, replace and split are made more consistent.
  Own Id: OTP-7514 Aux Id: OTP-7494
- Processes spawned using proc_lib (including gen_server and other library modules that use proc_lib) no longer keep the entire argument list for the initial call, but only the arity.
  Also, if proc_lib:spawn/1 is used to spawn a fun, the actual fun is not kept, but only module, function name, and arity of the function that implements the fun.
  The reason for the change is that keeping the initial fun (or a fun in an argument list), would prevent upgrading the code for the module. A secondary reason is that keeping the fun and function arguments could waste a significant amount of memory.
  The drawback with the change is that the crash reports will provide less precise information about the initial call (only Module:Function/Arity instead of Module:Function(Arguments)). The function proc_lib:initial_call/1 still returns a list, but each argument has been replaced with a dummy atom.
  Own Id: OTP-7531 Aux Id: seq11036
- There is now experimental support for loading of code from archive files. See the documentation of code, init, erl_prim_loader and escript for more info.
  The error handling of escripts has been improved.
  An escript may now set explicit arguments to the emulator, such as -smp enabled.
  An escript may now contain a precompiled beam file.
  An escript may now contain an archive file containing one or more applications (experimental).
  The internal module code_aux has been removed.
  Own Id: OTP-7548 Aux Id: otp-6622
- Enabled explicit control of which types of files that should be compressed in a ZIP archive.
  Own Id: OTP-7549 Aux Id: otp-6622
- In the job control mode, the "s" and "r" commands now take an optional argument to specify which shell to start. (Thanks to Robert Virding.)
  Own Id: OTP-7617

### 1.2 STDLIB 1.15.4

#### 1.2.1 Fixed Bugs and Malfunctions

- A bug in the calendar module could cause calendar:local_time_to_universal_time_dst/1 to return duplicate identical values for local times in timezones without DST. Multiple values should only be returned when a local time is within the hour occurring twice due to shift from DST to non-DST, and certainly only in timezones with DST. The correct behaviour is now implemented.
  Own Id: OTP-7344 Aux Id: seq10960
- The documentation of (d)ets:init_table() has been corrected. (Thanks to Paul Mineiro.)
  Own Id: OTP-7413
- The soft upper limit of 60 on the number of non-white characters on a line, which was introduced in R12B-0 for the control sequences p and P of the functions io:fwrite/2,3 and io_lib:fwrite/2, has been removed. This means that terms whose printed representation fits on a line will have no NEWLINEs. The Erlang shell still uses the 60 character limit, though.
  Own Id: OTP-7421 Aux Id: OTP-6708
- Some debug code has been removed from Dets.
  Own Id: OTP-7424
- The documentation of dets:match_delete/2 has been corrected. (Thanks to Paul Mineiro.)
  Own Id: OTP-7445
- Corrections of digraph(3). (Thanks to Vlad Dumitrescu.)
  Own Id: OTP-7492
- For the process that an escript runs in, the trap_exit process flag is now false instead of true (as in previous releases). Scripts that depend on the previous (counter-intuitive) behaviour might not work. (Thanks to Bengt Kleberg.)
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-7517

#### 1.2.2 Improvements and New Features

- The documentation of lists:(u)sort/2 now states what is expected of an ordering function.
  Own Id: OTP-7489
- The re module is exdended with repetitive matches (global option) and replacement function.
  Own Id: OTP-7494 Aux Id: OTP-7181
- The Erlang shell now displays a nicer error message when evaluating an undefined command. (Thanks to Richard Carlsson.)
  Own Id: OTP-7495

### 1.3 STDLIB 1.15.3

#### 1.3.1 Fixed Bugs and Malfunctions

- zip:unzip to/from binary with empty directories did not work. (Thanks to Martin Dvorak.)
  Own Id: OTP-7248
- The documentation of the control sequence w of the io_lib module now states that floating point numbers are printed accurately.
  Own Id: OTP-7324 Aux Id: OTP-7084
- zip:unzip was not supporting a flavour of the zip format found in jar-files.
  Own Id: OTP-7382 Aux Id: seq10970

#### 1.3.2 Improvements and New Features

- An experimental module "re" is added to the emulator which interfaces a publicly available regular expression library for Perl-like regular expressions (PCRE). The interface is purely experimental and *will* be subject to change.
  The implementation is for reference and testing in connection to the relevant EEP.
  Own Id: OTP-7181

### 1.4 STDLIB 1.15.2

#### 1.4.1 Fixed Bugs and Malfunctions

- When inserting many small objects, Dets sometimes crashed when reaching the maximum number of slots. (Thanks to Daniel Goertzen.)
  Own Id: OTP-7146
- Processes linked to the Erlang shell did not get an exit signal when the evaluator process was killed. This bug, introduced in R12B-0, has been fixed.
  Own Id: OTP-7184 Aux Id: OTP-6554
- Invalid arguments to ets:update_counter/3 were not handled correctly. A tuple position (Pos) less than 1 caused the element directly following the key to be updated (as if no position at all had been specified). All invalid values for Pos will now fail with badarg.
  Own Id: OTP-7226
- For certain terminals, io:columns/0 could return 0 instead of enotsup. That is now corrected.
  Own Id: OTP-7229 Aux Id: seq10886
- qlc:info() can now handle port identifiers, pids, references, and funs. (Thanks to Wojciech Kaczmare for reporting this bug.)
  When evaluating the parent_fun messages sent to the process calling qlc:cursor() were sometimes erroneously consumed. This bug has been fixed.
  Own Id: OTP-7232
- erl_parse:abstract() can now handle bit strings.
  Own Id: OTP-7234

#### 1.4.2 Improvements and New Features

- The queue module has been rewritten to make it easier to use. Suggestions and discussion from and with among others Lev Walkin, Anders Ramsell and Rober Virding in december 2007 on erlang-questions@erlang.org. It was also discussed to change the internal representation to contain length information which would speed up len/1 but that change has been postponed. Anyone interested may write an EEP and try to reach an acceptable compromise for queue overhead and thereby the speed of all other operations than len/1. The queue module is now optimized for fast and minimal garbage in/2 and out/1 and such. See the documentation.
  New functions: is_queue/1, get/1, get_r/1, peek/1, peek_r/1, drop/1, drop_r/1 and liat/1. is_queue/1 is a new predicate, liat/1 is a correction of an old misspelling, and the others (get*, peek* and drop*) are new interface functions.
  Own Id: OTP-7064
- The functions io_lib:write/1,2 and io_lib:print/1,4 have been changed when it comes to writing floating point numbers. This change affects the control sequences p, P, w, and W of the io_lib module. (Thanks to Bob Ippolito for code contribution.)
  Own Id: OTP-7084
- Updated the documentation for erlang:function_exported/3 and io:format/2 functions to no longer state that those functions are kept mainly for backwards compatibility.
  Own Id: OTP-7186
- A new BIF ets:update_element/3. To update individual elements within an ets-tuple, without having to read, update and write back the entire tuple.
  Own Id: OTP-7200
- string:join/2 now accepts an empty list as first argument.
  Own Id: OTP-7231 Aux Id: OTP-6671
- qlc:info/1,2 accepts a new option, depth. The type SelectedObjects used in the description of qlc:table/2 has been augmented.
  Own Id: OTP-7238
- tuple_size/1 and byte_size/1 have been substituted for size/1 in the documentation.
  Own Id: OTP-7244

### 1.5 STDLIB 1.15.1

#### 1.5.1 Fixed Bugs and Malfunctions

- Ets:select/3 in combination with ets:repair_continuation/2 and ordered_set data tables could result in function_clause although used as intended. This is now corrected. Thanks to Paul Mineiro for finding and isolating the bug!
  Own Id: OTP-7025
- The compiler warning for the deprecated function ftp:close/1 now mentions the correct replacement function.
  The warning for the removed functions in the httpd_util module have been changed to say they have been removed, not merely deprecated. (Thanks to Fredrik Thulin.)
  Own Id: OTP-7034 Aux Id: seq10825
- In (Expr)#r{} (no fields are updated), Expr is no longer evaluated more than once. There is also a test that Expr is of the correct record type. (Thanks to Dominic Williams.)
  Own Id: OTP-7078 Aux Id: OTP-4962
- Documentation bugfixes and clarifications.
  (Thanks to Joern (opendev@gmail.com), Matthias Lang, and Richard Carlsson.) Own Id: OTP-7079
- Duplicated objects were sometimes not deleted from the list of answers when a QLC table was traversed using a match specification. (Thanks to Dmitri Girenko.)
  Own Id: OTP-7114

#### 1.5.2 Improvements and New Features

- The documentation has been updated so as to reflect the last updates of the Erlang shell as well as the minor modifications of the control sequence p of the io_lib module.
  Superfluous empty lines have been removed from code examples and from Erlang shell examples.
  Own Id: OTP-6944 Aux Id: OTP-6554, OTP-6911
- tuple_size/1 and byte_size/1 have been substituted for size/1.
  Own Id: OTP-7009
- It is now possible to hibernate a gen_server/gen_event/gen_fsm. In gen_server and gen_fsm, hibernation is triggered by returning the atom 'hibernate' instead of a timeout value. In the gen_event case hibernation is triggered by a event handler returning a tuple with an extra element containing the atom 'hibernate'.
  Own Id: OTP-7026 Aux Id: seq10817
- Some undocumented debug functionality has been added to Dets.
  Own Id: OTP-7066
- The functions digraph_utils:is_tree/1, digraph_utils:is_arborescence/1, and digraph_utils:arborescence_root/1 are new.
  Own Id: OTP-7081
- The compiler could generate suboptimal code for record updates if the record update code consisted of multiple source code lines.
  Own Id: OTP-7101

### 1.6 STDLIB 1.15

#### 1.6.1 Fixed Bugs and Malfunctions

- Bugs have been fixed in qlc:
  - Setting the lookup_fun option of qlc:table/2 to undefined could cause a crash.
  - If a QLC restricted some column of a table in such a way that a traversal using a match specification was possible and the QLC also compared the key column or some indexed column of the the table with a column of some other table, qlc always chose to traverse the table first, never considering lookup join. This has been changed so that lookup join is always preferred; if an initial traversal using the match specification is desired, the query needs to be rewritten introducing an extra QLC with the filter(s) restricting the column.
  - When trying to find candidates for match specifications and lookup, filters using variables from one generator only are ignored unless they are placed immediately after the generator and possibly other filters using variables from the same generator. In particular, filters joining two tables should not be placed between the generator and the filters using the generator only.
  - The call-back function TraverseFun used for implementing QLC tables is allowed to return a term other than a list since STDLIB 1.14 (OTP-5195). However, when the returned term was a fun qlc often tried to call the fun instead of returning it.
  A few minor optimizations have been implemented as well.
  Own Id: OTP-6673
- A bug concerning the use of parameterized modules from the shell has been fixed.
  Own Id: OTP-6785
- A bug regarding the size expression of the bit syntax has been fixed in the erl_eval module.
  Own Id: OTP-6787
- The log_mf_h event handler didn't close the index file when it was done reading it causing a file descriptor leak.
  Own Id: OTP-6800
- Definitions for the filename() and dirname() types have been added to the documentation for the filelib module.
  Own Id: OTP-6870
- file:write_file/3, file:write/2 and file:read/2 could crash (contrary to documentation) for odd enough file system problems, e.g write to full file system. This bug has now been corrected.
  In this process the file module has been rewritten to produce better error codes. Posix error codes now originate from the OS file system calls or are generated only for very similar causes (for example 'enomem' is generated if a memory allocation fails, and 'einval' is generated if the file handle in Erlang is a file handle but currently invalid).
  More Erlang-ish error codes are now generated. For example {error,badarg} is now returned from file:close/1 if the argument is not of a file handle type. See file(3).
  The possibility to write a single byte using file:write/2 instead of a list or binary of one byte, contradictory to the documentation, has been removed.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6967 Aux Id: OTP-6597 OTP-6291
- A bug concerning the evaluation of the ++/2 operator has been fixed in erl_eval. (Thanks to Matthew Dempsky.)
  Own Id: OTP-6977

#### 1.6.2 Improvements and New Features

- The behaviour of the internal functions gen:call/3,4 has been changed slightly in the rare case that when the caller was linked to the called server, and the server crashed during the call; its exit signal was consumed by the gen:call/3,4 code and converted to an exit exception. This exit signal is no longer consumed.
  To even notice this change, 1) the calling process has to be linked to the called server.
  2) the call must not be remote by name that is it must be local or remote by pid, local by name or global by name.
  3) the calling process has to have set process_flag(trap_exit, true).
  4) the server has to crash during the call.
  5) the calling process has to be sensitive to getting previously consumed {'EXIT',Pid,Reason} messages in its message queue.
  The old behaviour was once the only way for a client to notice if the server died, but has since erlang:monitor(process, {Name,Node}) was introduced and used in gen:call been regarded as an undesired behaviour if not a bug.
  The affected user APIs are: gen_server:call/2,3, gen_fsm:sync_send_event/2,3, gen_fsm:sync_send_all_state_event/2,3, gen_event:_, sys:_ and maybe a few others that hardly will be noticed.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-3954 Aux Id: Seq 4538
- When an exception occurs the Erlang shell now displays the class, the reason, and the stacktrace in a clearer way (rather than dumping the raw EXIT tuples as before). proc_lib:format/1 displays the exception of crash reports in the same clearer way.
  The new shell command catch_exception and the new application configuration parameter shell_catch_exception can be used for catching exceptions that would normally exit the Erlang shell.
  Own Id: OTP-6554 Aux Id: OTP-6289
- The function string:join/2 joins strings in a list with a separator. Example: 'string:join(["a", "b", "c"], ", ") gives "a, b, c"'
  Own Id: OTP-6671
- The control sequence P of the Format argument of the functions io:fwrite/2,3 and io_lib:fwrite/2 now inserts fewer line breaks when printing tuples and lists. A soft upper limit of 60 on the number of non-white characters on a line has been introduced.
  Own Id: OTP-6708
- The new module array provides a fast functional array implementation.
  Own Id: OTP-6733
- Functions that have long been deprecated have now been removed from the following modules: dict, erl_eval, erl_pp, io, io_lib, lists, orddict, ordsets, sets, and string.
  The undocumented function lists:zf/3 has also been removed (use a list comprehension or lists:zf/2 instead).
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6845
- Minor documentation corrections for file:pread/2 and file:pread/3.
  Own Id: OTP-6853
- Contract directives for modules in Kernel and STDLIB.
  Own Id: OTP-6895
- The ets:fixtable/2 function, which has been deprecated for several releases, has been removed.
  The ets:info/1 function has been reimplemented as a BIF, which guarantees that information returned is consistent.
  The ets:info/2 function now fails with reason badarg if the second argument is invalid. (Dialyzer can be used to find buggy code where the second argument is misspelled.)
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6906
- The Erlang pretty printer erl_pp now inserts more newlines in order to facilitate line coverage analysis by Cover. (Thanks to Thomas Arts.)
  Own Id: OTP-6911
- The documentation for ets:safe_fixtable/2, ets:foldl/3, and ets:foldr/3 is now clearer about what will happen if objects are inserted during table traversals.
  Own Id: OTP-6928 Aux Id: seq10779
- It is now possible to extract files in tar files directly into binaries. It is also possible to add files to tar files directly from binaries.
  Own Id: OTP-6943
- The functions keystore/4 and keytake/3 are new in the lists module.
  Own Id: OTP-6953
- The new qlc option tmpdir_usage can be used for outputting messages onto the error logger when a temporary file is about to be created, or to prohibit the usage of temporary files altogether.
  Own Id: OTP-6964

### 1.7 STDLIB 1.14.5.3

#### 1.7.1 Improvements and New Features

- The allowed syntax for -type() and -spec() was updated.
  Own Id: OTP-6861 Aux Id: OTP-6834

### 1.8 STDLIB 1.14.5.2

#### 1.8.1 Improvements and New Features

- The compiler will for forward compatibility ignore the -type() and -spec() attributes that will be introduced in the R12B release.
  Own Id: OTP-6834

### 1.9 STDLIB 1.14.5.1

#### 1.9.1 Fixed Bugs and Malfunctions

- The log_mf_h event handler didn't close the index file when it was done reading it causing a file descriptor leak.
  Own Id: OTP-6800

#### 1.9.2 Improvements and New Features

- The dict:size/1 and orddict:size/1 functions have been documented.
  Own Id: OTP-6818

### 1.10 STDLIB 1.14.5

#### 1.10.1 Fixed Bugs and Malfunctions

- Bugs have been fixed in Dets concerning comparison (==) and matching (=:=).
  The STDLIB manual pages have been updated as to more carefully state when terms are matched and when they are compared.
  Own Id: OTP-4738 Aux Id: OTP-4685
- The shell has been updated to fix the following flaws: Shell process exit left you with an unresponsive initial shell if not using oldshell. Starting a restricted shell with a nonexisting callback module resulted in a shell where no commands could be used, not even init:stop/0. Fun's could not be used as parameters to local shell functions (in shell_default or user_default) when restricted_shell was active.
  Own Id: OTP-6537
- A bug in QLC's parse transform has been fixed.
  Own Id: OTP-6590
- A bug concerning lists:sort/1 and lists:keysort/2 and a mix of floating point numbers and integers has been fixed.
  Own Id: OTP-6606
- When calling erlang:garbage_collect/0 in the Erlang shell not only the evaluator process (the one returned by calling self() in the Erlang shell) is garbage collected, but also the process holding the history list.
  Own Id: OTP-6659
- Functions of the beam_lib module that used to catch exceptions and return a tuple {'EXIT',Reason} now exit with the reason Reason.
  Own Id: OTP-6711
- The erl_eval module now calls the non-local function handler whenever an operator is evaluated (exceptions are andalso, orelse, and catch). The non-local function handler is now also called when the function or operator occurs in a guard test (such calls used to be ignored).
  These changes affect the Erlang shell when running in restricted mode: the callback function non_local_allowed/3 is now called for operators such as '!'/2. This means that non_local_allowed/3 may need to be changed as to let operators through. Note that erlang:'!'/2 as well as erlang:send/2,3 have to be restricted in order to stop message passing in the shell.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6714 Aux Id: seq10374

#### 1.10.2 Improvements and New Features

- The new compiler option warn_obsolete_guard can be used for turning on warnings for calls to old type testing BIFs.
  Own Id: OTP-6585
- For scripts written using escript, there is a new function escript:script_name/0, which can be used to retrieve the pathame of the script. The documentation has been clarified regarding pre-defined macros such as ?MODULE and the module name.
  Own Id: OTP-6593
- Minor Makefile changes.
  Own Id: OTP-6689 Aux Id: OTP-6742

### 1.11 STDLIB 1.14.4

#### 1.11.1 Fixed Bugs and Malfunctions

- The MD5 calculation of a BEAM file done by code:module_md5/1, beam_lib:md5/1, and by the compiler for the default value of the vsn attribute have all been changed so that its result will be the same on all platforms; modules containing funs could get different MD5s on different platforms.
  Own Id: OTP-6459
- When sorting terms using the file_sorter module (the option Format set to term), file errors were not always properly handled. This bug has been fixed.
  The directory supplied with the tmpdir option is no longer checked unless it is actually used. The error reason not_a_directory can no longer be returned; instead a file_error tuple is returned
  Own Id: OTP-6526
- Bugs regarding try/catch have been fixed in the erl_eval module.
  Own Id: OTP-6539
- When sorting the operands of a join operation, QLC called file:open/3 with bad arguments. This bug has been fixed.
  Own Id: OTP-6562 Aux Id: seq10606

#### 1.11.2 Improvements and New Features

- The functions beam_lib:cmp/1 and beam_lib:strip/1 (and similar functions) have been updated to handle optional chunks (such as "FunT") in more general way in order to be future compatible.
  The function beam_lib:chunks/3 has been added.
  The function beam_lib:md5/1 has been added.
  Own Id: OTP-6443
- Added base64 as a module to stdlib, encoding and decoding
  Own Id: OTP-6470
- Added the functions to_upper/1 and to_lower/1 to the string module. These provide case conversion for ISO/IEC 8859-1 characters (Latin1) and strings.
  Own Id: OTP-6472
- The callback function non_local_allowed/3 used by the restricted shell can now return the value {{restricted,NewFuncSpec,NewArgList},NewState} which can be used for letting the shell call some other function than the one specified.
  Own Id: OTP-6497 Aux Id: seq10555
- There is a new escript program that can be used for writing scripts in Erlang. Erlang scripts don't need to be compiled and any arguments can be passed to them without risk that they are interpreted by the Erlang system.
  Own Id: OTP-6505
- The Format argument of the functions io:fwrite/2,3 and io_lib:fwrite/2 is now allowed to be a binary.
  Own Id: OTP-6517

### 1.12 STDLIB 1.14.3.1

#### 1.12.1 Fixed Bugs and Malfunctions

- The control sequences p and P of the Format argument of the functions io:fwrite/2,3 and io_lib:fwrite/2 could cause a badarg failure when applied to binaries. This bug was introduced in STDLIB 1.14.3. (Thanks to Denis Bilenko.)
  Own Id: OTP-6495

#### 1.12.2 Improvements and New Features

- Added the option {cwd, Dir} to make zip-archives with relative pathnames without having to do (a global) file:set_cwd.
  Own Id: OTP-6491 Aux Id: seq10551

### 1.13 STDLIB 1.14.3

#### 1.13.1 Fixed Bugs and Malfunctions

- The spawn_opt/2,3,4,5 option monitor -- introduced in Kernel 2.11.2 -- is currently not possible to use when starting a process using proc_lib, that is, also when starting a gen_server, gen_fsm etc.
  This limitation has now been properly documented and the behavior of the gen_fsm, gen_server, and proc_libstart and start_link functions when providing this option has been changed from hanging indefinitely to failing with reason badarg.
  (Thanks to Fredrik Linder)
  Own Id: OTP-6345

#### 1.13.2 Improvements and New Features

- The control sequence P of the Format argument of the functions io:fwrite/2,3 and io_lib:fwrite/2 now replaces the tail of binary strings with ... when the maximum depth has been reached. For instance, io:fwrite("~P", [<<"a binary string">>, 3]). prints <<"a binary"...>>.
  The indentation takes more care not to exceed the right margin, if possible.
  If the maximum depth is reached while printing a tuple, ,... is printed instead of |... (this change applies to the control sequence W as well).
  Own Id: OTP-6354
- The Erlang shell command h/0 that prints the history list now avoids printing (huge) terms referred to by v/1 but instead just prints the call to v/1.
  Own Id: OTP-6390

### 1.14 STDLIB 1.14.2.2

#### 1.14.1 Fixed Bugs and Malfunctions

- The functions dets:select/1,3, dets:match/1,3, and dets:match_object/1,3 have been changed as to never return {[],Continuation}. This change affects the corresponding functions in Mnesia.
  Bugs have been fixed in QLC: qlc:info() could crash if the tmpdir option did not designate a valid directory; the results of looking up keys are kept in RAM, which should improve performance.
  Own Id: OTP-6359

### 1.15 STDLIB 1.14.2.1

#### 1.15.1 Fixed Bugs and Malfunctions

- A bug in erl_pp:exprs() has been fixed.
  Own Id: OTP-6321 Aux Id: seq10497

### 1.16 STDLIB 1.14.2

#### 1.16.1 Fixed Bugs and Malfunctions

- The control sequences p and P of the Format argument of the functions io:format/2,3 and io_lib:format/2 did not handle binaries very well. This bug, introduced in stdlib-1.14, has been fixed.
  Own Id: OTP-6230
- filelib:wildcard(Wc, PathWithRedundantSlashes), where PathWithRedundantSlashes is a directory path containing redundant slashes, such as /tmp/ or //tmp, could return incorrect results. (Thanks to Martin Bjorklund.)
  Own Id: OTP-6271
- The Erlang code preprocessor crashed if the predefined macros ?MODULE or ?MODULE_STRING were used before the module declaration. This bug has been fixed.
  Own Id: OTP-6277

#### 1.16.2 Improvements and New Features

- Support for faster join of two tables has been added to the qlc module. There are two kinds of fast joins: lookup join that uses existing indices, and merge join that takes two sorted inputs. There is a new join option that can be used to force QLC to use a particular kind of join in some QLC expression.
  Several other changes have also been included:
  - The new tmpdir option of cursor/2, eval/2, fold/4, and info/2 can be used to set the directory that join uses for temporary files. The option also overrides the tmpdir option of keysort/3 and sort/2.
  - The new lookup option can be used to assert that constants are looked up when evaluating some QLC expression.
  - The cache and cache_all options accept new tags: ets, list, and no. The tag list caches answers in a list using a temporary file if the answers cannot be held in RAM. Combining {cache,list} and {unique, true} is equivalent to calling sort/2 with the option unique set to true. The old tags true (equivalent to ets) and false (equivalent to no) are recognized for backward compatibility.
  - The new option max_list_size can be used to set the limit where merge join starts to use temporary files for large equivalence classes and when answers cached in lists are put on temporary files.
  - There is a new callback is_sorted_key to be supplied as an option to table/2.
  - QLC analyzes each and every QLC expression when trying to find constants for the lookup function. Hitherto only QLC expressions with exactly one generator were analyzed.
    Note that only filters with guard syntax placed immediately after the generator are analyzed. The restriction to guard filters is an incompatible change. See qlc(3) for further details.
  - In a similar way several match specifications for traversal of QLC tables can be utilized for different generators of one single QLC expression.
  - A bug has been fixed: when caching answers to a sufficiently complex query it could happen that some answers were not returned.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6038
- The Erlang pretty printer (erl_pp) is now much faster when the code is deeply nested. A few minor bugs have been fixed as well.
  Own Id: OTP-6227 Aux Id: OTP-5924
- The Erlang shell now tries to garbage collect large binaries. Under certain circumstances such binaries could otherwise linger on for an indefinite amount of time.
  Own Id: OTP-6239
- To help Dialyzer find more bugs, many functions in the Kernel and STDLIB applications now only accept arguments of the type that is documented.
  For instance, the functions lists:prefix/2 and lists:suffix/2 are documented to only accept lists as their arguments, but they actually accepted anything and returned false. That has been changed so that the functions cause an exception if one or both arguments are not lists.
  Also, the string:strip/3 function is documented to take a character argument that is a character to strip from one or both ends of the string. Given a list instead of a character, it used to do nothing, but will now cause an exception.
  Dialyzer will find most cases where those functions are passed arguments of the wrong type.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6295

### 1.17 STDLIB 1.14.1

#### 1.17.1 Fixed Bugs and Malfunctions

- The functions c:y/1,2 which call yecc:file/1,2 are now listed by c:help/0.
  Documentation of c:y/1,2 has been added to c(3).
  The fact that the control sequence character s recognizes binaries and deep character lists has been documented in io(3). This feature was added in R11B-0 (OTP-5403).
  Own Id: OTP-6140
- The shell command rr() sometimes failed to read record definitions from file(s). This problem has been fixed.
  Own Id: OTP-6166 Aux Id: OTP-5878
- The nonlocal function handler in erl_eval, which is used for implementing the restricted mode of the Erlang shell, did not handle calls to erlang:apply/3 correctly. This bug has been fixed.
  Own Id: OTP-6169 Aux Id: seq10374
- ets:rename/1 could deadlock, or crash the SMP emulator when the table wasn't a named table.
  ets:next/2, and ets:prev/2 could return erroneous results on the SMP emulator.
  Own Id: OTP-6198 Aux Id: seq10392, seq10415
- When closing a Dets table the space management data was sometimes saved in such a way that opening the table could not be done without repairing the file. This bug has been fixed.
  Own Id: OTP-6206

### 1.18 STDLIB 1.14

#### 1.18.1 Fixed Bugs and Malfunctions

- A bugfix in QLC: two of the call-back functions used for implementing QLC tables, TraverseFun and LookupFun, are now allowed to return a term other than a list. Such a term is immediately returned as the results of the current query, and is useful mostly for returning error tuples.
  Several other minor bugs have been also been fixed.
  Own Id: OTP-5195
- The STDLIB modules error_logger_file_h and error_logger_tty_h now read the environment variable utc_log from the SASL application.
  Own Id: OTP-5535
- ets:info/1 has been corrected to behave according to the documentation and return a list of tuples, not a tuple with tuples.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-5639
- Referencing a so far undeclared record from the default value of some record declaration is from now on considered an error by the linter. It is also an error if the default value of a record declaration uses or binds a variable.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-5878
- When a file .hrl file is included using -include_lib, the include path is temporarily updated to include the directory the .hrl file was found in, which will allow that .hrl file to itself include files from the same directory as itself using -include. (Thanks to Richard Carlsson.)
  Own Id: OTP-5944
- Corrected filelib:ensure_dir/1 which sometimes returned true and sometimes ok to always return ok when successful. This goes against the documentation which said true, but ok was judged to be a more logical return value.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-5960 Aux Id: seq10240
- The shell now handles records better when used in calls on the form {Module, Function}(ArgList).
  Own Id: OTP-5990 Aux Id: OTP-5876
- The functions lists:ukeysort/2 and lists:ukeymerge/3 have been changed in such a way that two tuples are considered equal if their keys match.
  For the sake of consistency, lists:usort/2 and lists:umerge/3 have been modified too: two elements are considered equal if they compare equal.
  The file_sorter module has been modified in a similar way: the unique option now applies to the key (keysort() and keymerge()) and the ordering function (the option {order, Order} ).
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-6019
- Correction in documentation for ets:update_counter/3; failure with badarg also if the counter to be updated is the key.
  Own Id: OTP-6072
- When sorting terms using the file_sorter module and an ordering fun, the sort was not always stable. This bug has been fixed.
  Own Id: OTP-6088

#### 1.18.2 Improvements and New Features

- Improvements of the linter:
  - The compile attribute is recognized after function definitions.
  - The new compiler option nowarn_deprecated_function can be used for turning off warnings for calls to deprecated functions.
  - The new compiler option {nowarn_unused_function,[{Name,Arity}]} turns off warnings for unused local functions for the mentioned functions. The new options {nowarn_deprecated_function,[{Module,Name,Arity}]} and {nowarn_bif_clash,[{Name,Arity}]} work similarly.
  The Erlang code preprocessor epp now recognizes the file attribute. This attribute is meant to be used by tools such as Yecc that generate source code files.
  Own Id: OTP-5362
- The formatting option ~s of io:fwrite and io_lib:fwrite has been extended to handle arguments that are binaries or I/O lists.
  Own Id: OTP-5403
- The control sequences p and P of the Format argument of the functions io:format/2,3 and io_lib:format/2 have been changed as to display the contents of binaries containing printable characters as strings.
  Own Id: OTP-5485
- The linter emits warnings for functions exported more than once in export attributes.
  Own Id: OTP-5494
- A manual for STDLIB has been added, stdlib(6). It mentions the configuration parameters for the Erlang shell.
  Own Id: OTP-5530
- Added the zip module with functions for reading and creating zip archives. See zip(3).
  Own Id: OTP-5786
- Simple-one-for-one supervisors now store the pids of child processes using dict instead of a list. This significantly improves performance when there are many dynamic supervised child processes. (Thanks to Mickaël Rémond et al.)
  Own Id: OTP-5898
- When given the new option 'strict_record_tests', the compiler will generate code that verifies the record type for 'R#record.field' operations in guards. Code that verifies record types in bodies has already been generated since R10B, but in this release there will be a '{badrecord,RecordTag}' instead of a 'badmatch' if the record verification test fails. See the documentation for the compile module for more information.
  The Erlang shell always applies strict record tests.
  Own Id: OTP-5915 Aux Id: OTP-5714
- The Erlang pretty printer (erl_pp) now tries to insert line breaks at appropriate places.
  Own Id: OTP-5924
- The public option has been removed from digraph:new/1. The reason is that several functions in the digraph module are implemented using multiple ETS accesses, which is not thread safe. (Thanks to Ulf Wiger.)
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-5985
- The function lists:keyreplace/4 checks that the fourth argument (NewTuple) is a tuple.
  Own Id: OTP-6023
- Added an example of how to reconstruct source code from debug info (abstract code) to beam_lib(3). (Thanks to Mats Cronqvist who wrote the example.)
  Own Id: OTP-6073
- The new compiler option warn_unused_record is used for finding unused locally defined record types.
  Own Id: OTP-6105

### 1.19 STDLIB 1.13.12

#### 1.19.1 Fixed Bugs and Malfunctions

- shell_default:xm/1 has been added. It calls xref:m/1.
  Own Id: OTP-5405 Aux Id: OTP-4101
- Warnings are output whenever so far undeclared records are referenced from some default value of a record declaration. In STDLIB 1.14 (R11B) such forward references will cause a compilation error.
  Own Id: OTP-5878
- The linter's check of the deprecated attribute did not take the compile option export_all into account. This bug has been fixed.
  Own Id: OTP-5917
- The Erlang pretty printer did not handle try/catch correctly. This bug has been fixed.
  Own Id: OTP-5926
- Corrected documentation for lists:nthtail/3.
  Added documentation for lists:keymap/3.
  Tried to clarify some other type declarations and function descriptions in lists(3).
  Corrected documentation for timer:now_diff/2.
  Fixed broken links in gen_fsm(3), gen_server(3), io_lib(3) and lib(3).
  Own Id: OTP-5931
- Type checks have been added to functions in lists.erl.
  Own Id: OTP-5939

#### 1.19.2 Improvements and New Features

- The new STDLIB module erl_expand_records expands records in abstract code. It is used by the Erlang shell, which means that Compiler is no longer used by the shell.
  Own Id: OTP-5876 Aux Id: OTP-5435
- The compiler will now warn that the megaco:format_versions/1 function is deprecated.
  Own Id: OTP-5976

### 1.20 STDLIB 1.13.11

#### 1.20.1 Fixed Bugs and Malfunctions

- When calling gen_server:enter_loop with a registered server name, it was only checked that the registered name existed, not that it actually was the name of the calling process.
  Own Id: OTP-5854

#### 1.20.2 Improvements and New Features

- More detail on beam_lib:version/1 in documentation.
  Own Id: OTP-5789
- The new function io:read/3 works like io:read/1,2 but takes a third argument, StartLine.
  Own Id: OTP-5813
- The new function gen_fsm:enter_loop/4,5,6, similar to gen_server:enter_loop/3,4,5, has been added.
  Own Id: OTP-5846 Aux Id: seq10163
- The function c:i/1 is now exported.
  Own Id: OTP-5848 Aux Id: seq10164

### 1.21 STDLIB 1.13.10

#### 1.21.1 Fixed Bugs and Malfunctions

- A couple of type errors have been fixed in sofs.
  Own Id: OTP-5739
- The pre-processor used to complain that the macro definition '-define(S(S), ??S).' was circular, which it isn't. (Thanks to Richard Carlsson.)
  Own Id: OTP-5777

### 1.22 STDLIB 1.13.9

#### 1.22.1 Fixed Bugs and Malfunctions

- The linter, QLC and the module erl_pp did not handle the new 'fun M:F/A' construct in all situations. This problem has been fixed.
  Own Id: OTP-5644

#### 1.22.2 Improvements and New Features

- The manual pages for most of the Kernel and some of the STDLIB modules have been updated, in particular regarding type definitions.
  The documentation of the return value for erts:info/1 has been corrected.
  The documentation for erlang:statistics/1 now lists all possible arguments.
  Own Id: OTP-5360
- Replaced some tuple funs with the new fun M:F/A construct.
  The high-order functions in the lists module no longer accept bad funs under any circumstances. 'lists:map(bad_fun, [])' used to return '[]' but now causes an exception.
  Unused, broken compatibility code in the ets module was removed. (Thanks to Dialyzer.)
  Eliminated 5 discrepancies found by Dialyzer in the Appmon application.
  Own Id: OTP-5633
- The c:i/0 function will now run in a paged mode if there are more than 100 processes in the system. (Thanks to Ulf Wiger.)
  erlang:system_info(process_count) has been optimized and does now return exactly the same value as length(processes()). Previously erlang:system_info(process_count) did not include exiting processes which are included in length(processes()).
  The +P flag for erl, which sets the maximum number of processes allowed to exist at the same, no longer accepts values higher than 134217727. (You will still probably run out of memory before you'll be able to reach that limit.)
  Own Id: OTP-5645 Aux Id: seq9984

### 1.23 STDLIB 1.13.8

#### 1.23.1 Fixed Bugs and Malfunctions

- Very minor corrections in beam_lib and its documentation.
  Own Id: OTP-5589

#### 1.23.2 Improvements and New Features

- The erlang:port_info/1 BIF is now documented. Minor corrections of the documentation for erlang:port_info/2.
  Added a note to the documentation of the math module that all functions are not available on all platforms.
  Added more information about the '+c' option in the erl man page in the ERTS documentation.
  Own Id: OTP-5555
- The new fun M:F/A construct creates a fun that refers to the latest version of M:F/A. This syntax is meant to replace tuple funs {M,F} which have many problems.
  The new type test is_function(Fun,A) (which may be used in guards) test whether Fun is a fun that can be applied with A arguments. (Currently, Fun can also be a tuple fun.)
  Own Id: OTP-5584

### 1.24 STDLIB 1.13.7

#### 1.24.1 Fixed Bugs and Malfunctions

- filelib:wildcard/2 was broken (it ignored its second argument).
  Also, filelib:wildcard("Filename") (where the argument does not contain any meta-characters) would always return ["Filename"]. Corrected so that an empty list will be returned if "Filename" does not actually exist. (Same correction in filelib:wildcard/2.) (This change is a slight incompatibility.)
  filelib:wildcard/1,2 will generate a different exception when given bad patterns such as "{a,". The exception used to be caused by 'exit(missing_delimiter)' but is now 'erlang:error({badpattern,missing_delimiter})'.
  Own Id: OTP-5523 Aux Id: seq9824

#### 1.24.2 Improvements and New Features

- Further improvements of encrypted debug info: New option encrypt_debug_info for compiler.
  Own Id: OTP-5541 Aux Id: seq9837

### 1.25 STDLIB 1.13.6

#### 1.25.1 Fixed Bugs and Malfunctions

- When opening a Dets table read only an attempt was sometimes made to re-hash the table resulting in an error message. This problem has been fixed.
  Own Id: OTP-5487 Aux Id: OTP-4989

#### 1.25.2 Improvements and New Features

- It is now possible to encrypt the debug information in Beam files, to help keep the source code secret. See the documentation for compile on how to provide the key for encrypting, and the documentation for beam_lib on how to provide the key for decryption so that tools such as the Debugger, xref, or cover can be used.
  The beam_lib:chunks/2 functions now accepts an additional chunk type compile_info to retrieve the compilation information directly as a term. (Thanks to Tobias Lindahl.)
  Own Id: OTP-5460 Aux Id: seq9787

### 1.26 STDLIB 1.13.5

#### 1.26.1 Fixed Bugs and Malfunctions

- Closing a Dets table kept in RAM would cause a crash if the file could not be written. This problem has been fixed by returning an error tuple.
  Own Id: OTP-5402
- erl_pp now correctly pretty-prints fun F/A.
  Own Id: OTP-5412
- The Erlang shell failed if the compiler was not in the code path. This problem has been fixed, but in order to evaluate records the compiler is still needed.
  Own Id: OTP-5435
- Corrected the example in the documentation for ets:match/2. Also clarified that ets:update_counter/3 updates the counter atomically. (Thanks to Anders Svensson.)
  Own Id: OTP-5452 Aux Id: seq9770, seq9789

#### 1.26.2 Improvements and New Features

- The possibility to start the Erlang shell in parallel with the rest of the system was reintroduced for backwards compatibility in STDLIB 1.13.1. The flag to be used for this is now called async_shell_start and has been documented. New shells started from the JCL menu are not syncronized with init anymore. This makes it possible to start a new shell (e.g. for debugging purposes) even if the initial shell has not come up.
  Own Id: OTP-5406 Aux Id: OTP-5218
- The compiler will now produce warnings when using the deprecated functions in the snmp module.
  Own Id: OTP-5425
- The function c:zi/0 has been removed. Use c:i/0 instead.
  Own Id: OTP-5432
- Corrected two minor bugs found by the Dialyzer: Calling a parameterized module from a restricted shell (i.e. if shell:start_restricted/1 has been used) would crash the shell evaluator. A debug printout in gen_fsm had a clause that would never match; causing less information to be printed.
  And a somewhat more serious one also found by Dialyzer: rpc:yield/1 would crash unless the call started by rpc:async_call/4 had already finished; rpc:nb_yield(Key,infinity) would also crash.
  Cleaned up and removed redundant code found by Dialyzer in erlang:dmonitor_p/2.
  Own Id: OTP-5462

### 1.27 STDLIB 1.13.4

#### 1.27.1 Fixed Bugs and Malfunctions

- Bugs in the Erlang shell have been fixed.
  Own Id: OTP-5327
- Some dead code reported by Dialyzer was eliminated.
  A bug in dbg when tracing to wrap trace files has been corrected. It failed to delete any already existing wrap trace files with the same names when starting a new wrap trace.
  Own Id: OTP-5329
- The linter could output invalid warnings about bit patterns in record initializations. This problem has been fixed.
  Own Id: OTP-5338
- ordsets:is_set(NoList), where NoList is any term except a list, would crash. For consistency with sets:is_set/1 and gb_sets:is_set/1, it now returns false.
  Own Id: OTP-5341
- A BIF erlang:raise/3 has been added. See the manual for details. It is intended for internal system programming only, advanced error handling.
  Own Id: OTP-5376 Aux Id: OTP-5257

#### 1.27.2 Improvements and New Features

- The deprecated attribute is now checked by the linter. See xref(3) for a description of the deprecated attribute.
  Own Id: OTP-5276
- The restricted shell will now indicate if the return value from a user predicate is on an incorrect form.
  Own Id: OTP-5335

### 1.28 STDLIB 1.13.3

#### 1.28.1 Fixed Bugs and Malfunctions

- Bugs concerning unused and shadowed variables have been fixed in the linter.
  Own Id: OTP-5091
- A bug in the evaluator that caused the shell to choke on bit syntax expressions has been fixed.
  Own Id: OTP-5237
- io:format/2 et.al no longer crashes for some combinations of precision and value for format character "g". Previously it crashed if the precision P was 4 or lower and the absolute value of the float to print was lower than 10^4 but 10^(P-1) or higher. Now it will not crash depending on the value of the float.
  Own Id: OTP-5263
- Bugs in the handling of the bit syntax have been fixed in the Erlang shell.
  Own Id: OTP-5269
- gb_sets:del_element/2 was changed to do the same as gb_sets:delete_any/2 which was the original intention, not as gb_sets:delete/2. Code that relies on gb_sets:del_element/2 causing an error if the element does not exist must be changed to call gb_sets:delete/2 instead.
  The documentation was also updated to explicitly document functions that were only referred to as 'aliases' of a documented function. Also, a list of all functions common to the gb_sets, sets, and ordsets was added.
  *** POTENTIAL INCOMPATIBILITY ***
  Own Id: OTP-5277
- Debug messages have been removed from the QLC module.
  Own Id: OTP-5283

#### 1.28.2 Improvements and New Features

- The size of continuations returned from dets:match/1,3, dets:match_object/1,3, and dets:select/1,3 has been reduced. This affects the amount of data Mnesia sends between nodes while evaluating QLC queries.
  Own Id: OTP-5232

### 1.29 STDLIB 1.13.2

#### 1.29.1 Improvements and New Features

- The -rsh switch for starting a remote shell (introduced with OTP-5210) clashed with an already existing switch used by slave. Therefore the switch for the remote shell is now instead named -remsh.
  Own Id: OTP-5248 Aux Id: OTP-5210

### 1.30 STDLIB 1.13.1

#### 1.30.1 Fixed Bugs and Malfunctions

- The Pman 'trace shell' functionality was broken as has now been fixed. Furthermore, Pman could not correctly find the pid of the active shell if more than one shell process was running on the node. This has also been corrected.
  Own Id: OTP-5191
- When the undocumented feature "parameterized modules" was used, the ?MODULE macro did not work correctly.
  Own Id: OTP-5224

#### 1.30.2 Improvements and New Features

- You can now start Erlang with the -rsh flag which gives you a remote initial shell instead of a local one. Example:

                  erl -sname this_node -rsh other_node@other_host

  Own Id: OTP-5210
- The man page for the lists module has been updated with decscription of the new zip, unzip, and partition/2 functions.
  Own Id: OTP-5213
- The top level group leader used to be listed as job #1 in the job list in JCL mode. Since there is no shell associated with this process that can be connected to, it will no longer be listed.
  Own Id: OTP-5214
- The possibility to start the Erlang shell in parallel with the rest of the system has been reintroduced for backwards compatibility. Note that this old behaviour is error prone and should not be used unless for some reason necessary.
  Own Id: OTP-5218 Aux Id: seq9534
- The shell commands rr/1,2,3 now accepts wildcards when reading record definitions from BEAM files.
  Own Id: OTP-5226

stdlib 1.15.5
Copyright © 1991-2008 Ericsson AB