[Proposal] add a VSCode 'strict' option, but allow extra features

[mg979]

For example, let g:vsnip_vscode_strict = 1 to disable all features that are not VSCode compatible. Then you can enable extra features.

Reason: I'd like extra features implemented as keys in the snippet, like:

• line_pattern: only trigger if line matches pattern
• path_pattern: only trigger if file path matches pattern
• syntax_pattern: only trigger in syntax element with pattern
• syntax_no_pattern: don't trigger in syntax elements with pattern

There are snippet that I only want to trigger at the start of an empty line.
Or I have project-specific snippets, that I only want to trigger if the file path matches a certain pattern. Or there are snippets that I don't want to trigger in strings or comments, etc.

Example:

    "NO": {
        "description": "note",
        "body": [
            "[NOTE]",
            "====",
            "$TM_SELECTED_TEXT$0",
            "===="
        ],
        "prefix": [
            "NO"
        ],
        "line_pattern": "^NO$"
    },

[hrsh7th]

What do you think about vsnip key?
I think we should separate the plugin-specific configuration to one key.

[mg979]

Sounds good.

[hrsh7th]

I'm thinking of schema.

[hrsh7th]

{
  "describe": {
    "prefix": ["describe"],
    "body": [],
    "vsnip": {
      "trigger_pattern": ["^\s*describe"], // auto-expansion
      "bufname_pattern": ["*.test.ts"], // bufname selector
      "syntax_pattern": ["String"] // syntax selector
    }
  }
}

[hrsh7th]

{
  "describe": {
    "prefix": ["describe"],
    "body": [
      "..."
    ],
    "vsnip": {
      "syntax_not": ["Comment", "String"],
      "bufname": "\\.test\\.[jt]sx?",
      "auto_expand": "desc(",
    }
  }
}

The syntax or bufname are conditional options.
The conditional options can be having a suffix _not.

In what order should the options be applied?

[mg979]

I don't think it matters because all conditions should be satisfied, so snippet is expanded only if all conditions are true.

That is, all conditional options are tested in whatever order, if one fails the snippet can't expand.

[gzagatti]

I am wondering if there is any updates on this proposal. It would be great to have the ability to only trigger some snippets according to these line patterns.