feat: improve comment handling

src/strace/parser/peg.pest

@@ -32,15 +32,21 @@ argument = {
 	#in = in_argument
 }
 in_argument = { expression }
-in_out_argument = { expression ~ " => " ~ expression}
+in_out_argument = {
+	("[" ~ expression ~ " => " ~ expression ~ "]" ) |
+	(expression ~ " => " ~ expression)
+}
 
 expression = {
-	#macro = macro |
-	#int = int |
-	#struct = struct |
-	#buf = buffer |
-	#set = set |
-	#array = array
+	(
+		#macro = macro |
+		#int = int |
+		#struct = struct |
+		#buf = buffer |
+		#set = set |
+		#array = array
+	) ~
+	comment?
 }
 
 symbol_name = { (ASCII_ALPHA | ASCII_DIGIT | "_")+ }
@@ -59,19 +65,13 @@ literal_int = {
 }
 or = { named_constant ~ ("|" ~ int)+ }
 multiplication = { literal_int ~ ("*" ~ int)+ }
-named_constant = { symbol_name ~ int_metadata? }
+named_constant = { symbol_name ~ metadata? }
 
 literal_int_oct = { "0" ~ ASCII_OCT_DIGIT+ }
 literal_int_hex = { "0x" ~ ASCII_HEX_DIGIT+ }
-literal_int_dec = {
-	literal_int_dec_val ~
-	(
-		#mdata = int_metadata |
-		#com = comment
-	)?
-}
+literal_int_dec = { literal_int_dec_val ~ metadata? }
 literal_int_dec_val = { "-"? ~ ASCII_DIGIT+ }
-int_metadata = { "<" ~ buffer_byte+ ~ ">" }
+metadata = { "<" ~ buffer_byte+ ~ ">" }
 
 struct = {
 	"{" ~