Add link parser

src/org/org_text_link.nim

@@ -0,0 +1,35 @@
+import results
+import fusion/matching
+import ../utils/fp
+import ../parser/parser_internals
+import ../parser/parser_types
+
+{.experimental: "caseStmtMacros".}
+
+let linkStartParser* = ignore(str("[[")) + anyUntil(choice(@[str("]["), str("]]")])) + optional(ignore(str("][")))
+let linkEndParser* = anyUntil(str("]]")) + ignore(str("]]"))
+
+let linkParser* = proc(parser: Parser): ParserResult {.closure.} =
+  let linkUrl = linkStartParser(parser)
+  .flatMap(flattenParserTokens)
+
+  let linkValue = linkUrl
+  .map(emptyTokens)
+  .flatMap(linkEndParser)
+  .flatMap(flattenParserTokens)
+
+  case (linkUrl, linkValue):
+    of (Some(@key), Some(@value)):
+      ok(Parser(
+        state: value.state,
+        tokens: @[
+          key.tokens[0],
+          value.tokens[0],
+        ]
+      ))
+    else:
+      linkValue
+
+when isMainModule:
+  echo initParser("[[]]").linkParser()
+  echo initParser("[[Foo][Bar]]").linkParser()