undefined | Better HN

0 pointsdavepeck11mo ago0 comments

> Agreed, although this doesn't work as well for HTML or SQL that doesn't fit on one line.

PEP 750 t-strings literals work with python's tripe-quote syntax (and its lesser-used implicit string concat syntax):

    lots_of_html = t"""
       <div>
          <main>
             <h1>Hello</h1>
          </main>
       </div>
    """

My hope is that we'll quickly see the tooling ecosystem catch up and -- just like in JavaScript-land -- support syntax coloring and formatting specific types of content in t-strings, like HTML.

0 comments

neilv11mo ago

Yeah, editor support will help a lot. Though the PEP's way of doing things doesn't specify the language of the template where the literal occurs, so detection of that might have to be kludged.

(Or, in a sufficiently working program, an editor with semantic analysis access could use something like type inference in the Python side, to determine the language in a less-kludgey way.)

davepeckOP11mo ago

> doesn't specify the language of the template where the literal occurs

Yeah, something we spent a bunch of time considering. In the end, we decided it probably needed to stay out of scope for the PEP.

You're right that JavaScript has an easier time here. Most of the JS tools we looked at simply inspect the name of the tag and if it's (say) html, they attempt to color/format string content as HTML regardless of what the html() function actually does or the string's contents.

Currently, tools like black have no knowledge of types. I'm guessing some amount of kludging is to be expected on day one. But my hope is over the long term, we'll see a story emerge for how annotations can indicate the expected content type.

kazinator11mo ago

But that will not apply proper HTML escaping to the evil script element, allowing injection, and allows tags not to be closed:

    lots_of_html = t"""
       <div>
          <main>
             <p>{evil}>/p>
          <main>
       </span>
    """

pphysch11mo ago

lot_of_html isn't a string literal with dangerous elements smooshed into the trusted scaffolding like an f-string would do.

It's a template instance that still needs to be safely processed into a renderable string, e.g. by escaping whatever `evil` evaluates to and even validating the final HTML syntax.

kazinator11mo ago

I can easily end up unsafely processed. It's a footgun.

And why would you be validating HTML on the fly, when it's coming from your program, not as an input into it. Even if you can do it at program startup once for each template, it's still pointless overhead.

The whole thing is wrongheaded; exactly the kind of stove-pipe people end up inventing when they don't have metaprogramming.

3 more replies

j / k navigate · click thread line to collapse

0 pointsdavepeck11mo ago0 comments

> Agreed, although this doesn't work as well for HTML or SQL that doesn't fit on one line.

PEP 750 t-strings literals work with python's tripe-quote syntax (and its lesser-used implicit string concat syntax):

    lots_of_html = t"""
       <div>
          <main>
             <h1>Hello</h1>
          </main>
       </div>
    """

My hope is that we'll quickly see the tooling ecosystem catch up and -- just like in JavaScript-land -- support syntax coloring and formatting specific types of content in t-strings, like HTML.

0 comments

neilv11mo ago

Yeah, editor support will help a lot. Though the PEP's way of doing things doesn't specify the language of the template where the literal occurs, so detection of that might have to be kludged.

(Or, in a sufficiently working program, an editor with semantic analysis access could use something like type inference in the Python side, to determine the language in a less-kludgey way.)

davepeckOP11mo ago

> doesn't specify the language of the template where the literal occurs

Yeah, something we spent a bunch of time considering. In the end, we decided it probably needed to stay out of scope for the PEP.

kazinator11mo ago

But that will not apply proper HTML escaping to the evil script element, allowing injection, and allows tags not to be closed:

    lots_of_html = t"""
       <div>
          <main>
             <p>{evil}>/p>
          <main>
       </span>
    """

pphysch11mo ago

lot_of_html isn't a string literal with dangerous elements smooshed into the trusted scaffolding like an f-string would do.

It's a template instance that still needs to be safely processed into a renderable string, e.g. by escaping whatever `evil` evaluates to and even validating the final HTML syntax.

kazinator11mo ago

I can easily end up unsafely processed. It's a footgun.

The whole thing is wrongheaded; exactly the kind of stove-pipe people end up inventing when they don't have metaprogramming.

3 more replies

j / k navigate · click thread line to collapse