[GODCC][COMMITTED] list languages: add language extensions

[Jose E. Marchesi]

Also adapt to use the latest compiler eof_char and other fixes.

---
 src/godcc-compile.a68 |  2 +-
 src/godcc-list.a68    | 11 ++++++++++-
 src/json.a68          | 31 ++++++++++++++++++++-----------
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/godcc-compile.a68 b/src/godcc-compile.a68
index 64f8c1f..ad15686 100644
--- a/src/godcc-compile.a68
+++ b/src/godcc-compile.a68
@@ -68,7 +68,7 @@ begin
                        (n > 0 | puts (fgets (fd, n))));
       ce_disconnect;
 
-      { Close files whenever required.  }
+      { Close files.  }
       (in_fd /= 1 | fclose_checked (src_file, in_fd));
       (out_fd /= 1 | fclose_checked (out_file, out_fd))
 end;
diff --git a/src/godcc-list.a68 b/src/godcc-list.a68
index a7b3784..45c08e8 100644
--- a/src/godcc-list.a68
+++ b/src/godcc-list.a68
@@ -24,7 +24,16 @@ begin
             JSON_Val languages := ce_get_json ("languages");
             json_foreach_elem (languages,
                                (ref JSON_Val v) void:
-                                  puts (json_str (v->"id") + "'n"));
+                                  begin puts (json_str (v->"id"));
+                                        puts (" (");
+                                        int count := 0;
+                                        json_foreach_elem (v->"extensions",
+                                                           (ref JSON_Val e) void:
+                                                              ((count > 0 | puts (", "));
+                                                               puts (json_str (e));
+                                                               count +:= 1));
+                                        puts (")'n")
+                                  end);
             ce_disconnect
       end;
 
diff --git a/src/json.a68 b/src/json.a68
index 8143b6b..d3136d8 100644
--- a/src/json.a68
+++ b/src/json.a68
@@ -52,6 +52,16 @@ proc json_new_arr = JSON_Val: heap JSON_Arr;
 
 proc(string)void json_error := (string msg) void: (assert (false));
 
+{ Return the number of elements in a JSON array.  Return 0 for other
+  kind of objects.  }
+
+op LEN = (JSON_Val v) int:
+   case v
+   in (ref JSON_Arr a):
+         (int len := 0; json_foreach_elem (a, (ref JSON_Val v) void: len +:= 1); len)
+   out 0
+   esac;
+
 { The operator -> gets a JSON value, which must be an object, and a
   field name, and returns a name referring to the field of that name
   stored in the object.  If there is no such a field, one is created
@@ -131,14 +141,13 @@ proc json_from_fd = (int maxchars, int fd,
 begin
       { Simple stream of characters with EOF and error detection.  }
 
-      char eof = invalid_char;
-      char ungetch := eof, ch;
+      char ungetch := eof_char, ch;
       int usedchars;
 
       proc getchar = char:
-      begin if usedchars > maxchars then ch := eof
-            elif ungetch /= eof
-            then ch := ungetch; ungetch := eof
+      begin if usedchars > maxchars then ch := eof_char
+            elif ungetch /= eof_char
+            then ch := ungetch; ungetch := eof_char
             else ch := fgetc (fd); usedchars +:= 1
             fi;
             ch
@@ -152,13 +161,13 @@ begin
       proc expect = (string s) void:
          for i to UPB s
          do char c = s[i];
-            if getchar = eof orel ch /= c
+            if getchar = eof_char orel ch /= c
             then parse_error ("expected ''" + c + "''")
             fi
          od;
 
       proc parse_error = (string msg) void:
-         if ch = eof
+         if ch = eof_char
          then json_error (msg + ", found end of file")
          else json_error (msg + ", found ''" + ch + "''")
          fi;
@@ -179,10 +188,10 @@ begin
             proc parse_string = string:
             begin string res;
                   while getchar /= """"
-                  do if ch = eof then json_error ("while parsing string")
+                  do if ch = eof_char then json_error ("while parsing string")
                      elif ch = "\"
                      then ch = getchar;
-                          if ch = eof then json_error ("unterminated string escape")
+                          if ch = eof_char then json_error ("unterminated string escape")
                           elif ch = "n" then res +:= "'n"
                           elif ch = "t" then res +:= "'t"
                           elif ch = """" then res +:= """"
@@ -210,7 +219,7 @@ begin
                                   next of e := heap JSON_Elm := (val, nil);
                                   elems))
                   od;
-                  (ch = eof | parse_error ("unclosed array in JSON string"));
+                  (ch = eof_char | parse_error ("unclosed array in JSON string"));
                   heap JSON_Arr res;
                   elements of res := elems;
                   res
@@ -226,7 +235,7 @@ begin
                      JSON_Val value = parse_value (charsleft - usedchars);
                      fields := heap JSON_Fld := (name, value, fields)
                   od;
-                  (ch = eof | parse_error ("unclosed object in JSON string"));
+                  (ch = eof_char | parse_error ("unclosed object in JSON string"));
                   heap JSON_Obj res;
                   fields of res := fields;
                   res
-- 
2.30.2