File changes.md artifact f1cf13c59c part of check-in 1880179400
The source code for Tcl is managed by fossil. Tcl developers coordinate all changes to the Tcl source code at
Release Tcl 9.1a1 arises from the check-in with tag core-9-1-a1.
Highlighted differences between Tcl 9.1 and Tcl 9.0 are summarized below, with focus on changes important to programmers using the Tcl library and writing Tcl scripts.
New commands and options
- New options -backslashes, -commands and -variables for subst command
- New command unicode for Unicode normalization
New public C API
- Tcl_IsEmpty checks if the string representation of a value would be the empty string
- Tcl_GetEncodingNameForUser returns name of encoding from user settings
- Tcl_AttemptCreateHashEntry - version of Tcl_CreateHashEntry that returns NULL instead of panic'ing on memory allocation errors
- Tcl_ListObjRange, Tcl_ListObjRepeat, Tcl_TclListObjReverse - C API for new list operations
- Tcl_UtfToNormalized, Tcl_UtfToNormalizedDString - C API for Unicode normalization
Performance
- Memory efficient internal representations for list operations on large lists.
- Continued 64-bit capacity: Command line arguments larger than 2Gb