Update.

[bpt/guile.git] / NEWS

diff --git a/NEWS b/NEWS
index f6d4003..e5704b2 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,36 @@ debugging evaluator gives better error messages.
 
 * Changes to Scheme functions and syntax
 
+** New function 'unsetenv'.
+
+** There is support for Infinity and NaNs.
+
+Following PLT Scheme, Guile can now work with infinite numbers, and
+'not-a-numbers'.
+
+There is new syntax for numbers: "+inf.0" (infinity), "-inf.0"
+(negative infinity), "+nan.0" (not-a-number), and "-nan.0" (same as
+"+nan.0").  These numbers are inexact and have no exact counterpart.
+
+Dividing by an inexact zero returns +inf.0 or -inf.0, depending on the
+sign of the dividend.  The infinities are integers, and they answer #t
+for both 'even?' and 'odd?'. The +nan.0 value is not an integer and is
+not '=' to itself, but '+nan.0' is 'eqv?' to itself.
+
+For example
+
+    (/ 1 0.0)
+    => +inf.0
+
+    (/ 0 0.0)
+    => +nan.0
+
+    (/ 0)
+    ERROR: Numerical overflow
+
+Two new predicates 'inf?' and 'nan?' can be used to test for the
+special values.
+
 ** We now have uninterned symbols.
 
 The new function 'make-symbol' will return a uninterned symbol.  This
@@ -105,6 +135,20 @@ had problems because with them allocation and initialization was separated and
 the GC could sometimes observe half initialized cells.  Only careful coding by
 the user of SCM_NEWCELL and SCM_NEWCELL2 could make this safe and efficient.
 
+** CHECK_ENTRY, CHECK_APPLY and CHECK_EXIT have been deprecated.
+
+Use the variables scm_check_entry_p, scm_check_apply_p and scm_check_exit_p
+instead.
+
+** SRCBRKP has been deprecated.
+
+Use scm_c_source_property_breakpoint_p instead.
+
+** Removed from scm_root_state: def_inp, def_outp, def_errp.  These were
+unused copies of the standard ports when Guile was initialised.  The
+corresponding macros scm_def_inp, scm_def_outp and scm_def_errp were also
+removed.
+
 ** Removed definitions:  scm_lisp_nil, scm_lisp_t, s_nil_ify, scm_m_nil_ify,
 s_t_ify, scm_m_t_ify, s_0_cond, scm_m_0_cond, s_0_ify, scm_m_0_ify, s_1_ify,
 scm_m_1_ify, scm_debug_newcell,        scm_debug_newcell2, scm_tc16_allocated,