Work on CrossRef.

packages/CrossRef.sty

@@ -26,9 +26,10 @@
 
 \str_const:Nn \c_label_delimiter_str {/}
 \str_const:Nn \c_label_parent_str {.}
+\str_const:Nn \c_label_wildcard_str {~}
 \str_const:Nn \c_appendices_label_str {appendices}
 
-\seq_new:N \l_label_seq
+\seq_new:N \g_label_seq
 
 \NewDocumentCommand{\Part}{s t^ m >{\TrimSpaces}m}{
 	\_heading:nnnnn {part} {#1} {#2} {#3} {#4}
@@ -64,7 +65,7 @@
 }
 
 \NewDocumentCommand{\GetCurrentLabel}{}{
-	\seq_use:NV \l_label_seq \c_label_delimiter_str
+	\seq_use:Nn \g_label_seq {\c_label_delimiter_str}
 }
 
 \NewDocumentCommand{\SetCurrentLabel}{
@@ -73,61 +74,87 @@
 	% #2: Label string.
 	>{\TrimSpaces}m
 }{
-	\seq_set_split:Nee \l_label_seq {#1} {#2}
+	\seq_set_split:Nnn \g_label_seq {#1} {#2}
 }
 
-\int_new:N \l_level_index_int
-
-\seq_new:N \l_label_temp_seq
-\seq_new:N \l_ref_seq
-
-\str_new:N \l_ref_str
-
 \RenewDocumentCommand{\Ref}{
 	% #1: Star (No star = include section name in reference, star = do not include).
 	s
 	% #2: Label string delimiter (defaults to "/").
 	O{\c_label_delimiter_str}
-	% #3: Label
+	% #3: Label Reference
 	>{\TrimSpaces}m
 	% #4: Parent label symbol (defaults to ".").
 	O{\c_label_parent_str}
-}{
+	% #5: Label wildcard symbol (defaults to "~").
+	O{\c_label_wildcard_str}
+}{ \group_begin:
+	% Put the parameters in string variables so we can work with them.
+	\str_const:Nn \c_label_delimiter_str {#2}
+	\str_const:Nn \c_label_parent_str {#4}
+	\str_const:Nn \c_label_wildcard_str {#5}
+	\str_const:Ne \c_regex_str {
+		/|([\c_label_parent_str\c_label_wildcard_str])
+	}
+
+	\seq_new:N \l_label_seq
+	\seq_new:N \l_ref_seq
+
+	\str_new:N \l_ref_str
 	\str_set:Nn \l_ref_str {#3}
-	\str_if_eq:nnTF {\str_head:N \l_ref_str} {#2} {
-		\str_replace_all:Nnn \l_ref_str {#4} {#2}
-		\seq_set_split:Nee \l_ref_seq {#2} {#3}
 
-		\int_set:Nn \l_level_index_int {1}
+	% Split the string on the delimiters.
+	\seq_set_regex_split:NNn \l_ref_seq \c_regex_str {\l_ref_str}
+	
+	% Copy the current label sequence to a local variable.
+	\seq_set_eq:NN \l_label_seq \g_label_seq
+
+	% Iterate through the reference sequence, removing one element from the
+	% end of the temporary label sequence for each parent symbol.
+	\seq_map_indexed_function:NN \l_ref_seq \_seq_map:nn
+	
+	% If the first character in the label string is a delimiter, it is an
+	% absolute reference and we don't have to do anything to it. 
+	% Otherwise, we have to convert it from a relative reference to an absolute.
+	\str_if_eq:nnTF {\str_head:N \l_ref_str} {\c_label_delimiter_str} {
 
-		\int_do_until:nNnn {\l_level_index_int} > {\seq_count:N \l_ref_seq} {
-			\str_if_empty:nTF {\seq_item:Nn \l_ref_seq {\l_level_index_int}} {
-				\seq_set_item:Nnn \l_ref_seq {
-					\l_level_index_int
 	} {
-					\seq_item:Nn \l_label_seq {\l_level_index_int}
+		% Add a delimiter before each parent symbol so we can split the string.
+		\str_replace_all:Nnn \l_ref_str {\c_label_parent_str} {
+			\c_label_delimiter_str\c_label_parent_str
 		}
-			}
+		% Remove empty items from the sequence.
-			\int_incr:N \l_level_index_int
+		\seq_remove_all:Nn \l_ref_seq {}
-		}
+		% Add the shortened temporary label sequence to the beginning of the 
-
+		% reference sequence.
+		\seq_concat:NNN \l_ref_seq \l_label_seq \l_ref_seq
+		% Join the reference sequence back into a delimited string.
 		\str_set:Nn \l_ref_str {\seq_use:Nn \l_ref_seq {#1}}
-	} {
+		\str_put_left:Nn \l_ref_str {\c_label_delimiter_str}
-		\str_set:Nn \l_ref_str {#3}
 	} 
-
+	% Output the section name only if no star is passed.
 	\bool_if:nF {#1} {
-		% Section name
 		\str_if_eq:nnTF {\seq_item:Nn \l_ref_seq {1}} {\c_appendices_label_str} {
+			% If the part label is "appendices", the section name is "Appendix".
 			\prop_item:Nn \c_section_names_prop {9}
 		}{
+			% Otherwise, look up the correct section name.
 			\prop_item:Nn \c_section_names_prop {\seq_count:N \l_ref_seq - 1}
 		}
 	}
-		\str_put_left:Nn \l_ref_str {\c_label_delimiter_str}
+	% Create a reference with the string we just created.
 	\ref{\l_ref_str}
-}
 
+	\cs_new:Nn \_seq_map:nn {
+		\str_case:nn {#2} {
+			{\c_label_parent_str} {\seq_pop_right:NN \l_label_seq \l_tmpa_tl}
+			{\c_label_wildcard_str} {
+				\seq_item:Nn \l_label_temp_str {#1}}
+		}
+	}
+\group_end: }
+
+\int_new:N \l_level_index_int
 \int_new:N \l_section_level_int
 
 \cs_new:Nn \_heading:nnnnn {
@@ -146,13 +173,13 @@
 			\use:c {#1} {#4}
 		}
 	}
-	\int_set:Nn \l_level_index_int {\seq_count:N \l_label_seq}
+	\int_set:Nn \l_level_index_int {\seq_count:N \g_label_seq}
 	\int_do_while:nNnn  {\l_level_index_int} > {\l_section_level_int} {
-		\seq_pop_right:NN \l_label_seq \l_tmpa_tl
+		\seq_pop_right:NN \g_label_seq \l_tmpa_tl
 		\int_decr:N \l_level_index_int
 	}
-	\seq_put_right:Nn \l_label_seq {#5}
+	\seq_put_right:Nn \g_label_seq {#5}
-	\str_set:Nn \l_label_str {\seq_use:Nn \l_label_seq \c_label_delimiter_str}
+	\str_set:Nn \l_label_str {\seq_use:Nn \g_label_seq \c_label_delimiter_str}
 	\str_put_left:Nn \l_label_str {\c_label_delimiter_str}
 	\exp_args:Ne \label {\l_label_str}
 }