kc3-lang/kc3

diff --git a/c3s/c3s.c b/c3s/c3s.c
index cebd0d3..5fcb8ca 100644
--- a/c3s/c3s.c
+++ b/c3s/c3s.c
@@ -81,7 +81,7 @@ int main (int argc, char **argv)
   env_init(&env);
   while ((r = buf_xfer_spaces(&out, &in)) >= 0) {
     if ((r = buf_parse_tag(&in, &input)) > 0) {
-      if (! eval_tag(&env, &result, &input)) {
+      if (! env_eval_tag(&env, &result, &input)) {
         tag_clean(&input);
         continue;
       }
diff --git a/ic3/ic3.c b/ic3/ic3.c
index 6a4851a..3b49663 100644
--- a/ic3/ic3.c
+++ b/ic3/ic3.c
@@ -82,7 +82,7 @@ int main (int argc, char **argv)
   env_init(&env);
   while ((r = buf_xfer_spaces(&out, &in)) >= 0) {
     if ((r = buf_parse_tag(&in, &input)) > 0) {
-      if (! eval_tag(&env, &input, &result)) {
+      if (! env_eval_tag(&env, &input, &result)) {
         tag_clean(&input);
         continue;
       }
diff --git a/libc3/buf_file.c b/libc3/buf_file.c
index 3421a4a..fd075d5 100644
--- a/libc3/buf_file.c
+++ b/libc3/buf_file.c
@@ -36,6 +36,18 @@ void buf_file_close (s_buf *buf)
   buf->user_ptr = NULL;
 }
 
+e_bool buf_file_is_open (s_buf *buf)
+{
+  s_buf_file *buf_file;
+  assert(buf);
+  if (buf->user_ptr) {
+    buf_file = (s_buf_file *) buf->user_ptr;
+    if (! ferror(buf_file->fp) && ! feof(buf_file->fp))
+      return true;
+  }
+  return false;
+}
+
 s_buf * buf_file_open_r (s_buf *buf, FILE *fp)
 {
   s_buf_file *buf_file;
diff --git a/libc3/buf_file.h b/libc3/buf_file.h
index bda9d92..819c8d4 100644
--- a/libc3/buf_file.h
+++ b/libc3/buf_file.h
@@ -22,7 +22,7 @@
 #include "types.h"
 
 /* observers */
-bool    buf_file_is_open (s_buf *buf);
+e_bool    buf_file_is_open (s_buf *buf);
 
 /* modifiers */
 s_buf * buf_file_open_r (s_buf *buf, FILE *fp);
diff --git a/libc3/env.c b/libc3/env.c
index 263cb7b..ce72f3c 100644
--- a/libc3/env.c
+++ b/libc3/env.c
@@ -20,7 +20,6 @@
 #include "buf_inspect.h"
 #include "env.h"
 #include "error_handler.h"
-#include "eval.h"
 #include "frame.h"
 #include "list.h"
 #include "str.h"
@@ -85,24 +84,24 @@ s_tag * env_eval_call_fn (s_env *env, s_call *call, s_tag *dest)
   call_args = call->arguments;
   while (args) {
     if (! call_args) {
-      assert(! "eval_call_fn: missing argument");
-      errx(1, "eval_call_fn: missing argument");
+      assert(! "env_eval_call_fn: missing argument");
+      errx(1, "env_eval_call_fn: missing argument");
       return NULL;
     }
     /* TODO: check type */
-    eval_tag(env, &call_args->tag, &tmp);
+    env_eval_tag(env, &call_args->tag, &tmp);
     frame.bindings = binding_new(args->name, &call_args->tag,
                                  frame.bindings);
     args = args->next;
     call_args = list_next(call_args);
   }
   if (call_args) {
-    assert(! "eval_call_fn: too many arguments");
-    errx(1, "eval_call_fn: too many arguments");
+    assert(! "env_eval_call_fn: too many arguments");
+    errx(1, "env_eval_call_fn: too many arguments");
     return NULL;
   }
   env->frame = &frame;
-  eval_progn(env, fn->algo, dest);
+  env_eval_progn(env, fn->algo, dest);
   env->frame = frame_clean(&frame);
   return dest;
 }
@@ -125,8 +124,8 @@ const s_tag * env_eval_ident (s_env *env, s_ident *ident)
   assert(env);
   assert(ident);
   if (! (tag = frame_get(env->frame, ident->sym))) {
-    assert(! "eval_ident: unbound variable");
-    errx(1, "eval_ident: unbound variable");
+    assert(! "env_eval_ident: unbound variable");
+    errx(1, "env_eval_ident: unbound variable");
   }
   return tag;
 }
@@ -150,8 +149,8 @@ s_tag * env_eval_tag (s_env *env, s_tag *tag, s_tag *dest)
   switch (tag->type.type) {
   case TAG_VOID: return tag_init_void(dest);
   case TAG_CALL:
-    assert(! "eval_tag: invalid tag type: TAG_CALL");
-    errx(1, "eval_tag: invalid tag type TAG_CALL");
+    assert(! "env_eval_tag: invalid tag type: TAG_CALL");
+    errx(1, "env_eval_tag: invalid tag type TAG_CALL");
     return NULL;
   case TAG_CALL_FN:
     return env_eval_call_fn(env, &tag->data.call, dest);
@@ -182,8 +181,8 @@ s_tag * env_eval_tag (s_env *env, s_tag *tag, s_tag *dest)
   case TAG_VAR:
     return tag_copy(tag, dest);
   }
-  assert(! "eval_tag: invalid tag");
-  errx(1, "eval_tag: invalid tag");
+  assert(! "env_eval_tag: invalid tag");
+  errx(1, "env_eval_tag: invalid tag");
   return NULL;
 }
 
@@ -247,7 +246,7 @@ s_tag * env_unwind_protect (s_env *env, s_tag *protected, s_list *cleanup,
     env_eval_progn(env, cleanup, &tmp);
     longjmp(*unwind_protect.jmp, 1);
   }
-  eval_tag(env, protected, dest);
+  env_eval_tag(env, protected, dest);
   env_pop_unwind_protect(env);
   env_eval_progn(env, cleanup, &tmp);
   return dest;