* eval.c (symbol_value): Retrieve the binding of a symbol

macro also.
(boundp): Return t for symbol macros.
(makunbound, fmakunbound): New functions.
(eval_init): Register makunbound and fmakunbound.

* txr.1: Document changes to symbol-value and boundp,
and add dialect notes about the different semantics of binding.

1 files changed, 24 insertions, 2 deletions

diff --git a/eval.c b/eval.c
index beecc139..8a5b84df 100644
--- a/eval.c
+++ b/eval.c
@@ -3283,7 +3283,10 @@ static val mapdov(val fun, val list_of_lists)
 
 static val symbol_value(val sym)
 {
-  return cdr(lookup_var(nil, sym));
+  uses_or2;
+
+  return cdr(or2(lookup_var(nil, sym),
+                 lookup_symac(nil, sym)));
 }
 
 static val symbol_function(val sym)
@@ -3296,7 +3299,7 @@ static val symbol_function(val sym)
 
 static val boundp(val sym)
 {
-  return if3(lookup_var(nil, sym), t, nil);
+  return if2(lookup_var(nil, sym) || lookup_symac(nil, sym), t);
 }
 
 static val fboundp(val sym)
@@ -3305,6 +3308,23 @@ static val fboundp(val sym)
              gethash(op_table, sym), t);
 }
 
+static val makunbound(val sym)
+{
+  lisplib_try_load(sym),
+  remhash(top_vb, sym);
+  remhash(top_smb, sym);
+  remhash(special, sym);
+  return sym;
+}
+
+static val fmakunbound(val sym)
+{
+  lisplib_try_load(sym),
+  remhash(top_fb, sym);
+  remhash(top_mb, sym);
+  return sym;
+}
+
 static val rangev_func(val env, val lcons)
 {
   cons_bind (from, to_step, env);
@@ -4370,6 +4390,8 @@ void eval_init(void)
   reg_fun(intern(lit("symbol-function"), user_package), func_n1(symbol_function));
   reg_fun(intern(lit("boundp"), user_package), func_n1(boundp));
   reg_fun(intern(lit("fboundp"), user_package), func_n1(fboundp));
+  reg_fun(intern(lit("makunbound"), user_package), func_n1(makunbound));
+  reg_fun(intern(lit("fmakunbound"), user_package), func_n1(fmakunbound));
   reg_fun(intern(lit("func-get-form"), user_package), func_n1(func_get_form));
   reg_fun(intern(lit("func-get-env"), user_package), func_n1(func_get_env));
   reg_fun(intern(lit("func-set-env"), user_package), func_n2(func_set_env));