Changes in Tcl/Tk 8.6

This page is a terse summary of script-visible changes in Tcl/Tk 8.6, presented as bullet lists with links to more detail. For a more narrative, feature-based introduction to 8.6 capabilities, see The major new features of Tcl/Tk 8.6.

Tcl Changes

New Backslash Syntax

\Uhhhhhhhh [TIP #388 ]
\xhh limited to at most two digits [TIP #388 ]
\4dd–\7dd is now handled like \04dd–\07dd [TIP #388 ]

Changes to Tcl Commands

New Commands

coroutine [TIP #328 ]
lmap [TIP #405 ]
oo::class [TIP #257 , TIP #320 , TIP #380 , TIP #397 ]
oo::copy
oo::define
oo::objdefine
oo::object
tailcall [TIP #327 ]
tcl::prefix [TIP #195 ]
throw
try [TIP #329 ]
yield [TIP #328 ]
yieldto [TIP #396 ]
zlib [TIP #234 , TIP #400 ]

New Subcommands

Expanded Syntax / New Options

close chan read|write [TIP #332 ]
dict filter dict type pattern ... [TIP #341 ]
file delete (zero pathnames) [TIP #323]
file mkdir (zero pathnames) [TIP #323]
format %b [TIP #343 ]
glob (zero patterns) [TIP #323]
global (zero variable names) [TIP #323]
lassign (zero variable names) [TIP #323]
linsert (zero elements) [TIP #323]
load -global -lazy [TIP #416 ]
lrepeat (zero elements; zero repetitions) [TIP #323]
lsearch -bisect [TIP #313 ]
lsort -stride [TIP #326 ]
namespace ensemble create -parameters [TIP #314 ]
- see ensemble with parameters for more information
namespace upvar (zero variable names) [TIP #323]
return -errorstack [TIP #348 ]
scan string %b [TIP #343 ]
tcl::tm::path add (zero pathnames) [TIP #323]
tcl::tm::path list [TIP #323]
tcl::tm::path remove (zero pathnames) [TIP #323]
variable (zero variable names) [TIP #323]

New unsupported commands

Changes to Tcl variables

New global variables

tcl_platform(pathSeparator) [TIP #315 ]

Changed Tcl behavior

The following commands are script-modifiable ensembles: array, binary, file, namespace
lset can now set the element at index end+1, growing the list. [TIP #331 ]
string trim* and string is space now uses a different set of whitespace characters as a default.[TIP #318 , TIP #413 ]
encoding system during startup is now iso8859-1, not identity.
socket support for IPv6 addresses [TIP #162 ]
exit no longer performs full finalization.
Non-blocking channels no longer forced to flush on exit. [TIP #398 ]

Tk Changes

Changes to Tk Commands

New Commands

New Subcommands

canvas moveto [TIP #236 ]
canvas imove [TIP #97 ]
canvas rchars
tk busy [TIP #321 ]
tk fontchooser [TIP #324 ]

Expanded Syntax / New Options

canvas create text ... -angle degrees [TIP #119 ]
text configure -insertunfocussed none|hollow|solid [TIP #197 ]
image create photo -format png [TIP #244 ]
treeview tag names|add|remove
photo data -format GIF
wm attributes -type [TIP #359 ]

Changed Tk behavior

tk is a script-modifiable ensemble.
GIF photo images written with LZW compression.
event generate can now generate <Focus*> events.
Tk for OS X/Aqua now built on Cocoa libraries.
image write -file uses file name extension as format hint.
Revised <MouseWheel> event handlers. [TIP #171 ].
Color names redefined to match Web conventions [TIP #403 ]
X11 menu behavior modernized [TIP #360 ]

New Events

<<ContextMenu>>
<<LineEnd>>
<<LineStart>>
<<NextChar>>
<<NextLine>>
<<NextPara>>
<<NextWindow>>
<<NextWord>>
<<PrevChar>>
<<PrevLine>>
<<PrevPara>>
<<PrevWord>>
<<SelectAll>>
<<SelectLineEnd>>
<<SelectLineStart>>
<<SelectNextChar>>
<<SelectNextLine>>
<<SelectNextWord>>
<<SelectNone>>
<<SelectPrevChar>>
<<SelectPrevLine>>
<<SelectPrevPara>>
<<SelectPrevWord>>
<<ToggleSelection>>

See the documentation for event for explanations, and "event info <event>" to find out what bindings are used for each on your OS.

Changes to Bundled Packages

New packages

Itcl 4.0.0 [TIP #50 ]
sqlite3 3.7.14 [TIP #376 ]
tdbc 1.0.0 [TIP #308 ]
tdbc::mysql 1.0.0 [TIP #308 ]
tdbc::odbc 1.0.0 [TIP #308 ]
tdbc::postgres 1.0.0 [TIP #308 ]
tdbc::sqlite3 1.0.0 [TIP #308 ]
Thread 2.7.0 [TIP #364 ]

Updated packages

dde 1.4.0 [TIP #106 ]
registry 1.3.0 [TIP #362 ]
http 2.8.5
tcltest 2.3.5
msgcat 1.5.0 [TIP #404 ]