feat(single): Implement escaping

1 files changed, 24 insertions, 2 deletions

diff --git a/single.awk b/single.awk
index ab207a1..e19117d 100644
--- a/single.awk
+++ b/single.awk
@@ -18,9 +18,9 @@
 #     [x] Images
 #         [x] Inline
 #         [x] Reference
-# [.] Other
+# [x] Other
 #     [x] Autolinks
-#     [ ] Escapes
+#     [x] Escapes
 #
 # [ ] Non-standard features
 #     [ ] Strikethrough ~~...~~
@@ -83,6 +83,15 @@ BEGIN {
 	for (i = 1; i < 97; ++i) {
 		char_to_dec[char(ascii, i)] = 31 + i
 	}
+
+	## We do character escaping by substituting the escape with some
+	## "useless" characters, which we're confident won't appear in actual text.
+	## These are from decimal value 14 to 28 inclusive. They're blank characters,
+	## related to shifting, device control and data transmission.
+	escapable = "\\`*_{}[]()#+-.!"
+	for (i = 1; i < 16; ++i) {
+		escapes[char(escapable, i)] = sprintf("%c", 13 + i)
+	}
 }
 
 {
@@ -108,6 +117,13 @@ BEGIN {
 	next
 }
 
+# Escapes
+!inside_codeblock && /\\[-\\`*_{}\[\]()#+.!]/ {
+	while (match($0, /\\[-\\`*_{}\[\]()#+.!]/)) {
+		sub_match(escapes[char($0, RSTART + 1)])
+	}
+}
+
 # Blockquotes
 blockquote_level > 0 && empty0 {
 	for (P1 = P1 ORS; blockquote_level > 0; --blockquote_level) {
@@ -330,6 +346,12 @@ function __buffered_print() {
 			N1 = ""
 		}
 	}
+
+	## Fix escaped characters
+	for (i = 1; i < 16; ++i) {
+		esc = char(escapable, i)
+		gsub(escapes[esc], esc, P2)
+	}
 }
 
 END {