goldmark: Instructions file for Codex

Instructions for agents

Testing instructions

• use make test to run tests
• use make lint to run linters

Benchmark instructions

• use make bench to run benchmarks
  • this will output cpu profiler data to cpu.pprof file

Coding conventions

• Make sure to pass make lint
• Use util.StringToReadOnlyBytes and util.ReadOnlyBytesToString when converting between readonly strings and readonly byte slices to avoid unnecessary allocations.
• Before making changes, you must run make bench. After making changes, you should run make bench again to compare the performance before and after your changes.
  • If your changes cause a significant performance regression, you should analyze cpu.pprof to identify the bottlenecks and optimize your code accordingly.

Key point of CommonMark spec

• In most cases, punctuation characters can be escaped with a backslash (\) to prevent them from being interpreted as Markdown syntax. For example, \* will render as * instead of starting an emphasis.

• Spec defines sets of character categories. Use util package to check if a character belongs to a specific category. For example, util.IsPunct can be used to check if a character is a punctuation character. DO NOT use standard library functions like unicode.IsPunct as they may not cover all cases defined in the CommonMark spec.

• Most of inline elements (like emphasis, links, etc.) can exist within multiple lines. And they can be nested. So inline elements probably have multiple divided segments:

  > [lin
  > nk](https://example.com)
  

  In this case, the link element has two divided segments: lin and nk. When parsing, you should keep track of these segments and combine them when necessary. This kind of elements should have text.MultiLineValue instead of text.SingleLineValue.

• Paragraph rendering can be changed by parent elements. For example, a paragraph inside a tight list item should not have <p> tags, while a paragraph inside a block quote should have <p> tags.

• Tabs can be 1,2,3,4 spaces or raw tab character, depending on its position. When parsing block elements, you should aware of this and calculate the correct indentation level.