Accept optional "display names" in query mode.

* NEWS: Update.
* src/editem.c: Extend frame spec syntax.

2 files changed, 57 insertions, 28 deletions

diff --git a/NEWS b/NEWS
index 5a618ef..9d1e8f7 100644
--- a/NEWS
+++ b/NEWS
@@ -48,48 +48,66 @@ Prints verbose frame descriptions instead of their short names.
 The argument, if supplied, is a comma-separated list of the
 frame names to delete.
 
-* Comment content descriptors are displayed at the output.
+* Frame qualifiers are displayed at the output.
 
-In query mode, non-empty comment content descriptors are printed in square
-brackets before their corresponding values.  All comment fields are
-concatenated and shown as a single one, e.g.:
+Certain frames hold a set of additional fields, apart from their
+actual value and can appear mutliple times provided that those
+additional field differ.  We call these fields "frame qualifiers".
+For example, comment frames (COMM) have two qualifiers: language
+and content descriptor.
 
-comment: Test [RESULT] value [CDDB_TrackNumber] 8.
-
-In all-frames mode, each comment field is shown individually, with the
-corresponding language code and descriptor:
+In query mode, qualifiers are displayed after the corresponding frame
+name and are separated by colons, e.g.:
 
 comment:eng:RESULT: value
 comment:eng:CDDB_TrackNumber: 8
 
-* When setting or deleting comment fields, qualifiers are accepted.
+* All idest operations accept qualified frame names.
 
-Optional qualifiers specify language and content descriptor of the
-field.  The extended syntax for setting comment fields is:
+The full syntax is:
 
-  --set comment:LANG:DESCR=VALUE
+  NAME:QUAL
 
-Where LANG is a valid 3-character language code and DESCR is the
-content descriptor.  If LANG is omitted, "eng" is assumed.  Examples:
+Where NAME is a frame name or ID and QUAL stands for a list of
+qualifiers separated by colons.  Empty
+qualifiers and '*' act as wildcards, matching any actual field value.
+For example:
 
+  --query title,comment::my-comment
+  --delete=comment:eng:my-comment
   --set comment:esp:mi-comentario="Valor de prueba"
   --set comment::my-comment="Test value"
 
+* Frame display names in query mode
+
+Frame specifications in query mode can contain optional "frame display
+name".  When present, it will be displayed instead of the frame ID.
+The full syntax is:
+
+   NAME%ID[:QUAL]
+
+(See above for a description of the optional QUAL part).  For example:
+
+   idest --query Title%TIT2,Artist%TPE1,Author%TOLY,Composer%TCOM *.mp3
+  
 * Changes in Scheme representation of frame lists.
 
 Each frame in the list is represented as a cons.  Car of this
 cons is the frame name (a string).  Its cdr is an association list
 keeping this frame properties.  Keys in this list are property
-IDs (Scheme symbols).  Following properties are defined:
+IDs (Scheme symbols).  The following properties are defined for
+all frames:
 
   descr                frame description
   text                 value of this frame
+
+More properties are defined at a per-frame basis to represent
+frame qualifiers.  For example, for "comment" (COMM) frames:
+  
   lang                 a three-letter code of the language in which
                        the text is written
   condesc              content descriptor
 
-The two latter properties are defined only for comment frames.
-  
 * Guile startup files.
 
 When run with the --script option, idest searches for files .idest.scm,
diff --git a/src/editem.c b/src/editem.c
index ba03c91..1054d4f 100644
--- a/src/editem.c
+++ b/src/editem.c
@@ -158,18 +158,32 @@ ed_item_from_frame_spec(const char *arg, size_t len)
 	struct ed_item itm;
 	struct id3_frametype const *frametype;
 	struct idest_frametab const *ft;
+	size_t n;
 	const char *id;
+	char *idstr;
 	
 	ed_item_zero(&itm);
 	if (split_item_name(&itm, arg, len))
 		error(1, 0, "ivalid frame spec: %s", arg);
 
-	id = name_to_frame_id(itm.name);
+	n = strcspn(itm.name, "%");
+	if (itm.name[n]) {
+		char *s = xmalloc(n + 1);
+		memcpy(s, itm.name, n);
+		s[n] = 0;
+
+		idstr = xstrdup(itm.name + n + 1);
+		free(itm.name);
+		itm.name = s;
+	} else
+		idstr = itm.name;
+	
+	id = name_to_frame_id(idstr);
 	if (!id) {
-		frametype = id3_frametype_lookup(itm.name, strlen(itm.name));
+		frametype = id3_frametype_lookup(idstr, strlen(idstr));
 		if (!frametype) 
-			error(1, 0, "%s: unknown frame name", itm.name);
-		id = itm.name;
+			error(1, 0, "%s: unknown frame name", idstr);
+		id = idstr;
 	} else {
 		frametype = id3_frametype_lookup(id, 4);
 		assert(frametype != NULL);
@@ -180,6 +194,10 @@ ed_item_from_frame_spec(const char *arg, size_t len)
 		error(1, 0, "don't know how to handle frame %s", id);
 
 	memcpy(itm.id, id, sizeof(itm.id));
+
+	if (idstr != itm.name)
+		free(idstr);
+	
 	if (itm.qc > ft->qc)
 		error(1, 0,
 		      "too many field qualifiers for this frame: %s", arg);
@@ -192,13 +210,6 @@ ed_item_from_frame_spec(const char *arg, size_t len)
 	return ed_item_dup(&itm);
 }
 
-struct ed_item *
-ed_item_from_frame(struct id3_frame *frame)
-{
-	//FIXME;
-	abort();
-}
-
 void
 ed_item_print(struct ed_item const *itm)
 {