Opened 7 months ago
Closed 7 months ago
New point version
Changes in 3.0.5 (since 3.0.4)
* New interfaces and functionality
** O(1) compilation of `case' and related expressions
Guile now optimizes chains of eq? comparisons to constants, resulting in
O(1) dispatch time, regardless of the length of the chain. This
optimization is also unlocked in many cases for `match' expressions with
many similar clauses whose first differentiator are constants.
** New (ice-9 copy-tree) module
This module includes the `copy-tree' procedure that was previously
implemented in C and present in the default `(guile)' module. See
"Copying" in the manual.
** New warning: use-before-definition
This analysis, enabled at `-W1', issues warnings for programs that use
top-level variables before they are defined.
** New warning: non-idempotent-definition
This analysis, enabled at `-W1', issues warnings for programs that whose
use of a variable is ambiguous. For example, in the program:
(define saved-add +)
(define + error)
The intention would seem to be to "save" the value of the base `+'
procedure, then override it locally. However if this program is ever
loaded twice, then the second time it is loaded, `+' will be taken from
the local binding instead of the import. Users that want this kind of
behavior should either use lexical bindings instead of top-level
bindings, or otherwise rename important clobbered bindings via modules.
* New deprecations
** `copy-tree' in the default environment, and `scm_copy_tree' from C
Import the `(ice-9 copy-tree)' module instead.
** `unbound-variable-analysis`, `macro-use-before-definition-analysis`
These bindings from `(language tree-il analyze)' are replaced by the
use-before-definition analysis, which powers a number of warnings. Use
`make-use-before-definition-analysis', but note that these interfaces
are quite intimate parts of the compiler!
* Incompatible changes
** `copy' read-option removed
This read option would include a copy of the source expression in the
source-properties of each subexpression. This option has always been
off by default and lost most of its use value with the switch to a
compiler in Guile 2.0.
Fixed at r24093
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