# v1.4.0 - yyyy-mm-dd
## Standard library additions and changes
- Added `xmltree.newVerbatimText` support create `style`'s,`script`'s text.
- `uri` adds Data URI Base64, implements RFC-2397.
- Add [DOM Parser](https://developer.mozilla.org/en-US/docs/Web/API/DOMParser)
to the `dom` module for the JavaScript target.
- The default hash for `Ordinal` has changed to something more bit-scrambling.
`import hashes; proc hash(x: myInt): Hash = hashIdentity(x)` recovers the old
one in an instantiation context while `-d:nimIntHash1` recovers it globally.
- `deques.peekFirst` and `deques.peekLast` now have `var Deque[T] -> var T` overloads.
- File handles created from high-level abstractions in the stdlib will no longer
be inherited by child processes. In particular, these modules are affected:
`system`, `nativesockets`, `net` and `selectors`.
For `net` and `nativesockets`, an `inheritable` flag has been added to all
`proc`s that create sockets, allowing the user to control whether the
resulting socket is inheritable. This flag is provided to ease the writing of
multi-process servers, where sockets inheritance is desired.
For a transistion period, define `nimInheritHandles` to enable file handle
inheritance by default. This flag does **not** affect the `selectors` module
due to the differing semantics between operating systems.
`system.setInheritable` and `nativesockets.setInheritable` is also introduced
for setting file handle or socket inheritance. Not all platform have these
`proc`s defined.
- The file descriptors created for internal bookkeeping by `ioselector_kqueue`
and `ioselector_epoll` will no longer be leaked to child processes.
- `strutils.formatFloat` with `precision = 0` has been restored to the version
1 behaviour that produces a trailing dot, e.g. `formatFloat(3.14159, precision = 0)`
is now `3.`, not `3`.
- `critbits` adds `commonPrefixLen`.
- `relativePath(rel, abs)` and `relativePath(abs, rel)` used to silently give wrong results
(see #13222); instead they now use `getCurrentDir` to resolve those cases,
and this can now throw in edge cases where `getCurrentDir` throws.
`relativePath` also now works for js with `-d:nodejs`.
- JavaScript and NimScript standard library changes: `streams.StringStream` is
now supported in JavaScript, with the limitation that any buffer `pointer`s
used must be castable to `ptr string`, any incompatible pointer type will not
work. The `lexbase` and `streams` modules used to fail to compile on
NimScript due to a bug, but this has been fixed.
The following modules now compile on both JS and NimScript: `parsecsv`,
`parsecfg`, `parsesql`, `xmlparser`, `htmlparser` and `ropes`. Additionally
supported for JS is `cstrutils.startsWith` and `cstrutils.endsWith`, for
NimScript: `json`, `parsejson`, `strtabs` and `unidecode`.
- Added `streams.readStr` and `streams.peekStr` overloads to
accept an existing string to modify, which avoids memory
allocations, similar to `streams.readLine` (#13857).
- Added high-level `asyncnet.sendTo` and `asyncnet.recvFrom`. UDP functionality.
- `paramCount` & `paramStr` are now defined in os.nim instead of nimscript.nim for nimscript/nimble.
- `dollars.$` now works for unsigned ints with `nim js`
- Improvements to the `bitops` module, including bitslices, non-mutating versions
of the original masking functions, `mask`/`masked`, and varargs support for
`bitand`, `bitor`, and `bitxor`.
- `sugar.=>` and `sugar.->` changes: Previously `(x, y: int)` was transformed
into `(x: auto, y: int)`, it now becomes `(x: int, y: int)` in consistency
with regular proc definitions (although you cannot use semicolons).
Pragmas and using a name are now allowed on the lefthand side of `=>`. Here
is an aggregate example of these changes:
```nim
import sugar
foo(x, y: int) {.noSideEffect.} => x + y
# is transformed into
proc foo(x: int, y: int): auto {.noSideEffect.} = x + y
```
- The fields of `times.DateTime` are now private, and are accessed with getters and deprecated setters.
- The `times` module now handles the default value for `DateTime` more consistently. Most procs raise an assertion error when given
an uninitialized `DateTime`, the exceptions are `==` and `$` (which returns `"Uninitialized DateTime"`). The proc `times.isInitialized`
has been added which can be used to check if a `DateTime` has been initialized.
- Fix a bug where calling `close` on io streams in osproc.startProcess was a noop and led to
hangs if a process had both reads from stdin and writes (eg to stdout).
- The callback that is passed to `system.onThreadDestruction` must now be `.raises: []`.
- `osproc.execCmdEx` now takes an optional `input` for stdin.
- `osproc.execCmdEx` now takes an optional `input` for stdin, `workingDir` and `env`
parameters.
## Language changes
- In the newruntime it is now allowed to assign discriminator field without restrictions as long as case object doesn't have custom destructor. Discriminator value doesn't have to be a constant either. If you have custom destructor for case object and you do want to freely assign discriminator fields, it is recommended to refactor object into 2 objects like this:
```nim
type
MyObj = object
case kind: bool
of true: y: ptr UncheckedArray[float]
of false: z: seq[int]
proc `=destroy`(x: MyObj) =
if x.kind and x.y != nil:
deallocShared(x.y)
x.y = nil
```
Refactor into:
```nim
type
MySubObj = object
val: ptr UncheckedArray[float]
MyObj = object
case kind: bool
of true: y: MySubObj
of false: z: seq[int]
proc `=destroy`(x: MySubObj) =
if x.val != nil:
deallocShared(x.val)
x.val = nil
```
- getImpl() on enum type symbols now returns field syms instead of idents. This helps
with writing typed macros. Old behavior for backwards compatiblity can be restored
with command line switch `--useVersion:1.0`.
- ``let`` statements can now be used without a value if declared with
``importc``/``importcpp``/``importjs``/``importobjc``.
- The keyword `from` is now usable as an operator.
- Exceptions inheriting from `system.Defect` are no longer tracked with
the `.raises: []` exception tracking mechanism. This is more consistent with the
built-in operations. The following always used to compile (and still does):
```nim
proc mydiv(a, b): int {.raises: [].} =
a div b # can raise an DivByZeroDefect
```
Now also this compiles:
```nim
proc mydiv(a, b): int {.raises: [].} =
if b == 0: raise newException(DivByZeroDefect, "division by zero")
else: result = a div b
```
The reason for this is that `DivByZeroDefect` inherits from `Defect` and
with `--panics:on` `Defects` become unrecoverable errors.
## Compiler changes
- Specific warnings can now be turned into errors via `--warningAsError[X]:on|off`.
- The `define` and `undef` pragmas have been de-deprecated.
- New command: `nim r main.nim [args...]` which compiles and runs main.nim, saving
the binary to $nimcache/main$exeExt, using the same logic as `nim c -r` to
avoid recompiling when sources don't change. This is now the preferred way to
run tests, avoiding the usual pain of clobbering your repo with binaries or
using tricky gitignore rules on posix. Example:
```nim
nim r compiler/nim.nim --help # only compiled the first time
echo 'import os; echo getCurrentCompilerExe()' | nim r - # this works too
nim r compiler/nim.nim --fullhelp # no recompilation
nim r --nimcache:/tmp main # binary saved to /tmp/main
```
- `--hint:processing` is now supported and means `--hint:processing:on`
(likewise with other hints and warnings), which is consistent with all other bool flags.
(since 1.3.3).
- `nim doc -r main` and `nim rst2html -r main` now call openDefaultBrowser
## Tool changes