feat(single): Implement lists

1 files changed, 65 insertions, 2 deletions

diff --git a/single.awk b/single.awk
index e7d55e4..34917bc 100644
--- a/single.awk
+++ b/single.awk
@@ -1,12 +1,12 @@
 # Status:
 # [.] Inline HTML
 # [x] Autoescape
-# [.] Block elements
+# [x] Block elements
 #     [x] Paragraph
 #     [x] Line break
 #     [x] Headers (atx and setex)
 #     [x] Blockquotes
-#     [ ] Lists
+#     [x] Lists
 #     [x] Code blocks
 #     [x] Horizontal rules
 # [x] Span elements
@@ -104,6 +104,7 @@ BEGIN {
 	not_paragraph = 0
 	empty0  = empty($0)
 	emptyP1 = empty(P1)
+	list_started = 0
 }
 
 # Output is buffered on multiple lines, held in these variables:
@@ -160,6 +161,68 @@ blockquote_level > 0 && empty0 {
 }
 /^>$/ { $0 = ""; not_paragraph = 1 }
 
+# Lists
+function end_list() {
+	if (list_level == 0) return
+	P2 = P2 ORS "</li></" (lists[list_level] == "." ? "o" : "u") "l>"
+	--list_level
+}
+function start_list(level, type) {
+	## Every two columns we define a new level
+	level = int((level + 2) / 2)
+	## If list definition is the first line inside a code block
+	if (level - list_level >= 3) return
+
+	## Make list_level = level - 1
+	while (list_level < level - 1) {
+		lists[++list_level] = ""
+	}
+	## Make list_level = level
+	while (list_level > level) {
+		end_list()
+	}
+
+	if (list_level == level && lists[list_level] != type) {
+		end_list()
+	}
+	if (list_level < level || lists[list_level] != type) {
+		P1 = P1 ORS "<" (type == "." ? "o" : "u") "l><li>"
+		lists[level] = type
+		list_level = level
+	}
+	else {
+		PNappnd("</li>")
+		P1 = P1 ORS "<li>"
+	}
+	not_paragraph = 1
+	list_started = 1
+}
+!inside_codeblock && /^[ \t]*[*+-] / { ## Unordered list
+	match($0, /^[ \t]*[*+-] /)
+	level = RLENGTH - 2
+	type  = char($0, RSTART + RLENGTH - 2)
+	sub(/^[^*+-]*[*+-] /, "")
+
+	start_list(level, type)
+}
+!inside_codeblock && /^[ \t]*[0-9]+\. / { ## Ordered list
+	match($0, /^[ \t]*/)
+	level = RLENGTH
+	type  = "."
+	sub(/^[^.]+\. /, "")
+
+	start_list(level, type)
+}
+list_level > 0 && !list_started && /[^ \t]/ { ## Non-list line
+	match($0, /^[ \t]*/)
+	level = int((RLENGTH + 2) / 2)
+	while (list_level >= level) {
+		end_list()
+	}
+	$0 = substr($0, 2 * level - 1)
+	not_paragraph = 1
+}
+
 # Code blocks
 /^    / {
 	if (!inside_codeblock) {