Nim/changelog.md

v0.20.0 - XX/XX/2019

Changes affecting backwards compatibility

• The isLower, isUpper family of procs in strutils/unicode operating on strings have been deprecated since it was unclear what these do. Note that the much more useful procs that operator on char or Rune are not affected.

• strutils.editDistance has been deprecated, use editdistance.editDistance or editdistance.editDistanceAscii instead.

• The OpenMP parallel iterator `||` now supports any #pragma omp directives and not just #pragma omp parallel for. See OpenMP documentation.

  The default annotation is parallel for, if you used OpenMP without annotation the change is transparent, if you used annotations you will have to prefix your previous annotations with parallel for.

• The unchecked pragma was removed, instead use system.UncheckedArray.

• The undocumented #? strongSpaces parsing mode has been removed.

• The not operator is now always a unary operator, this means that code like assert not isFalse(3) compiles.

• getImpl on a var or let symbol will now return the full IdentDefs tree from the symbol declaration instead of just the initializer portion.

• To use multi-methods, explicit --multimethods:on is now needed.

Breaking changes in the standard library

• osproc.execProcess now also takes a workingDir parameter.

• options.UnpackError is no longer a ref type and inherits from system.Defect instead of system.ValueError.

• system.ValueError now inherits from system.CatchableError instead of system.Defect.

• The procs parseutils.parseBiggsetInt, parseutils.parseInt, parseutils.parseBiggestUInt and parseutils.parseUInt now raise a ValueError when the parsed integer is outside of the valid range. Previously they sometimes raised a OverflowError and sometimes returned 0.

• streams.StreamObject now restricts its fields to only raise system.Defect, system.IOError and system.OSError. This change only affects custom stream implementations.

• nre's RegexMatch.{captureBounds,captures}[] no longer return Option or nil/"", respectivly. Use the newly added n in p.captures method to check if a group is captured, otherwise you'll recieve an exception.

• nre's RegexMatch.{captureBounds,captures}.toTable no longer accept a default parameter. Instead uncaptured entries are left empty. Use Table.getOrDefault() if you need defaults.

• nre's RegexMatch.captures.{items,toSeq} now returns an Option[string] instead of a string. With the removal of nil strings, this is the only way to indicate a missing match. Inside your loops, instead of capture == "" or capture == nil, use capture.isSome to check if a capture is present, and capture.get to get its value.

• nre's replace() no longer throws ValueError when the replacement string has missing captures. It instead throws KeyError for named captures, and IndexError for un-named captures. This is consistant with RegexMatch.{captureBounds,captures}[].

• splitFile now correctly handles edge cases, see #10047

• isNil is no longer false for undefined in the JavaScript backend: now it's true for both nil and undefined. Use isNull or isUndefined if you need exact equallity: isNil is consistent with ===, isNull and isUndefined with ==.

• several deprecated modules were removed: ssl, matchers, httpserver, unsigned, actors, parseurl

• two poorly documented and not used modules (subexes, scgi) were moved to graveyard (they are available as Nimble packages)

Breaking changes in the compiler

• The compiler now implements the "generic symbol prepass" for when statements in generics, see bug #8603. This means that code like this does not compile anymore:

proc enumToString*(enums: openArray[enum]): string =
  # typo: 'e' instead 'enums'
  when e.low.ord >= 0 and e.high.ord < 256:
    result = newString(enums.len)
  else:
    result = newString(enums.len * 2)

• discard x is now illegal when x is a function symbol.
• Implicit imports via --import: module in a config file are now restricted to the main package.

Library additions

• There is a new stdlib module std/editdistance as a replacement for the deprecated strutils.editDistance.

• There is a new stdlib module std/wordwrap as a replacement for the deprecated strutils.wordwrap.

• Added split, splitWhitespace, size, alignLeft, align, strip, repeat procs and iterators to unicode.nim.

• Added or for NimNode in macros.

• Added system.typeof for more control over how type expressions can be deduced.

• Added macros.isInstantiationOf for checking if the proc symbol is instantiation of generic proc symbol.

• Added the parameter isSorted for the sequtils.deduplicate proc.

• There is a new stdlib module std/diff to compute the famous "diff" of two texts by line.

• Added os.relativePath.

• Added parseopt.remainingArgs.

• Added os.getCurrentCompilerExe (implmented as getAppFilename at CT), can be used to retrieve the currently executing compiler.

• Added xmltree.toXmlAttributes.

• Added std/sums module for fast summation functions.

• Added Rusage, getrusage, wait4 to posix interface.

• Added the posix_utils module.

• Added system.default.

Library changes

• The string output of macros.lispRepr proc has been tweaked slightly. The dumpLisp macro in this module now outputs an indented proper Lisp, devoid of commas.

• Added macros.signatureHash that returns a stable identifier derived from the signature of a symbol.

• In strutils empty strings now no longer matched as substrings anymore.

• Complex type is now generic and not a tuple anymore.

• The ospaths module is now deprecated, use os instead. Note that os is available in a NimScript environment but unsupported operations produce a compile-time error.

• The parseopt module now supports a new flag allowWhitespaceAfterColon (default value: true) that can be set to false for better Posix interoperability. (Bug #9619.)

• os.joinPath and os.normalizePath handle edge cases like "a/b/../../.." differently.

• securehash is moved to lib/deprecated

Language additions

• Vm support for float32<->int32 and float64<->int64 casts was added.
• There is a new pragma block noSideEffect that works like the gcsafe pragma block.
• added os.getCurrentProcessId()
• User defined pragmas are now allowed in the pragma blocks
• Pragma blocks are no longer eliminated from the typed AST tree to preserve pragmas for further analysis by macros
• Custom pragmas are now supported for var and let symbols.
• Tuple unpacking is now supported for constants and for loop variables.

Language changes

• The standard extension for SCF (source code filters) files was changed from .tmpl to .nimf, it's more recognizable and allows tools like github to recognize it as Nim, see #9647. The previous extension will continue to work.
• Pragma syntax is now consistent. Previous syntax where type pragmas did not follow the type name is now deprecated. Also pragma before generic parameter list is deprecated to be consistent with how pragmas are used with a proc. See #8514 and #1872 for further details.

Tool changes

• jsondoc now include a moduleDescription field with the module description. jsondoc0 shows comments as it's own objects as shown in the documentation.
• nimpretty: --backup now defaults to off instead of on and the flag was un-documented; use git instead of relying on backup files.

Compiler changes

• The deprecated fmod proc is now unavailable on the VM'.
• A new --outdir option was added.
• The compiled JavaScript file for the project produced by executing nim js will no longer be placed in the nimcache directory.
• The --hotCodeReloading has been implemented for the native targets. The compiler also provides a new more flexible API for handling the hot code reloading events in the code.

Bugfixes