能否使用PureScript解析XML？关于purescript-xml库的疑问

Hey Jonathan, great question—building an XSLT-like tool with PureScript makes total sense given its functional strengths, so let's break this down for you. First off: you're not missing anything. The old purescript-xml library is indeed unmaintained and no longer hosted on Pursuit. That's a bummer, but there are solid alternatives to get your XML parsing up and running smoothly.

Top Alternatives to Consider #

1. Use JavaScript's Native DOMParser via PureScript FFI #

This is probably the most straightforward and reliable approach, especially for a web app. PureScript plays really nicely with JavaScript, so you can easily wrap the browser's built-in DOMParser to parse XML into a manipulable structure.

Here's a quick example of how you might set this up:

import Effect (Effect)
import Effect.Class.Console (log)
import Web.DOM.Document (Document)
import Web.DOM.DOMParser (DOMParser, newDOMParser, parseFromString)
import Web.DOM.Node (nodeName)
import Web.DOM.Element (Element, toNode)
import Web.DOM.NonElementParentNode (querySelector)

parseXML :: String -> Effect (Maybe Document)
parseXML xmlStr = do
  parser <- newDOMParser
  parseFromString parser xmlStr "application/xml"

-- Example usage
main :: Effect Unit
main = do
  maybeDoc <- parseXML "<root><item>Hello XML</item></root>"
  case maybeDoc of
    Just doc -> do
      maybeItem <- querySelector doc "item"
      case maybeItem of
        Just item -> log =<< nodeName (toNode item)
        Nothing -> log "Target item not found in XML"
    Nothing -> log "Failed to parse XML input"

This leverages the browser's battle-tested XML parsing, so you don't have to reinvent the wheel, and it integrates seamlessly with PureScript's effect system.

2. Explore Active Community-Maintained Libraries #

While purescript-xml is gone, there are a few newer or more active XML-related projects in the PureScript ecosystem. Head to GitHub and search for "purescript xml"—you'll find options that either:

• Offer pure PureScript XML parsers (great if you want to avoid JS dependencies entirely)
• Wrap popular JavaScript XML libraries (like xmldom for cross-environment support)
  Just be sure to check the commit history and issue tracker to confirm the library is still being updated.

3. Roll Your Own Minimal Parser (If Your XML Is Simple) #

If your use case only requires parsing a specific, well-defined XML structure (not full general-purpose XML), you could write a small parser using PureScript's purescript-parsing library. This gives you full control over the parsing logic and fits perfectly with the functional programming paradigm you're already using.

Bonus: Aligning with XSLT-Style Functionality #

Since you're building an XSLT-like tool, PureScript's functional features (pattern matching, recursion, pure functions) are ideal for transforming XML nodes once parsed. You can create functions that take parsed XML elements and map them to HTML or other output formats—mirroring XSLT's template-based transformation but with the type safety of PureScript.

内容的提问来源于stack exchange，提问作者Jonathan