feat(awk): Implemented reference links

1 files changed, 20 insertions, 10 deletions

diff --git a/single.awk b/single.awk
index 415e042..f366ead 100644
--- a/single.awk
+++ b/single.awk
@@ -81,6 +81,12 @@ function autoinsert(arrname, isbefore) {
 	next
 }
 
+# Link definition
+/^\[.+\]:/ {
+	blankline = 1
+	next
+}
+
 # Auto-escape &
 /&/ {
 	ampstart = 0
@@ -252,29 +258,33 @@ blankline {
 }
 
 # Links
-/!?\[[^\]]*\]\([^)]*\)/ {
+/!?\[[^\]]*\] ?[(\[][^)\]]*[\])]/ {
 	isimg = 0
-	while (match($0, /!?\[[^\]]*\]\(/)) {
+	while (match($0, /!?\[[^\]]*\] ?[(\[]/)) {
 		if (substr($0, RSTART, 1) == "!") {
 			isimg = 1
 			RSTART++
 			RLENGTH--
 		}
 		astart = RSTART ## astart = indexof("[")
-		inner_anchor = substr($0, RSTART + 1, RLENGTH - 3) ## ...[xxxxx](...)...
+		has_space = substr($0, RSTART + RLENGTH - 2, 1) == " "
+		inner_anchor = substr($0, RSTART + 1, RLENGTH - 3 - has_space) ## ...[xxxxx](...)...
 
 		aend = RSTART + RLENGTH - 1
-		match(substr($0, astart), /\]\([^)]*\)/)
-		aend += RLENGTH - 2 ## aend = indexof(")")
-		href = substr($0, astart + RSTART + 1, RLENGTH - 3) ## ...[...](xxxxx)...
+		match(substr($0, astart), /\] ?[(\[][^)\]]*[\])]/)
+		aend += RLENGTH - 2 - has_space ## aend = indexof(")")
+		href = substr($0, astart + RSTART + 1 + has_space, RLENGTH - 3 - has_space) ## ...[...](xxxxx)...
 
-		if (match(href, /[ \t]"[^"]*"[ \t]*$/)) {
+		title = "\"\""
+		if (substr($0, astart + RSTART + has_space, 1) == "[") { ## is reference link
+			if (href == "") href = inner_anchor
+			title = reference[href, "title"]
+			href = reference[href, "href"]
+		}
+		else if (match(href, /[ \t]"[^"]*"[ \t]*$/)) { ## has title
 			title = substr(href, RSTART + 1, RLENGTH - 1)
 			href  = substr(href, 1, RSTART - 1)
 		}
-		else {
-			title = "\"\""
-		}
 		sub(/[ \t]+/, "", href)
 
 		if (isimg) elem = "<img src=\"" href "\" alt=\"" inner_anchor "\" title=" title ">"