filter.md

Filter

Examples

A simple filter is a table whose keys are item attributes. The following filter keeps items with attribute buf = 0 and ft = 'lua', i.e., diagnostics from the current buffer with filetype lua.

{
  modes = {
    my_diagnostics = {
      mode = 'diagnostics',
      filter = { buf = 0, ft = 'lua' },
    },
  },
}

A filter may be a function that takes items as parameter. The following filter keeps items with severity HINT

{
  modes = {
    my_diagnostics = {
      mode = 'diagnostics',
      filter = function(items)
        return vim.tbl_filter(function(item)
          return item.severity == vim.diagnostic.severity.HINT
        end, items)
      end,
    },
  },
}

Advanced examples

The not filter

The not negates filter results. The following filter removes diagnostics with severity INFO

{
  modes = {
    my_diagnostics = {
      mode = 'diagnostics',
      filter = {
        ['not'] = { severity = vim.diagnostic.severity.INFO },
      },
    },
  },
}

The any filter

The any filter provides logical disjunction. The following filter keeps diagnostics for the current buffer or diagnostics with severity ERROR for the current project.

{
  modes = {
    my_diagnostics = {
      mode = 'diagnostics',
      filter = {
        any = {
          buf = 0,
          {
            severity = vim.diagnostic.severity.ERROR,
            function(item)
              return item.filename:find((vim.loop or vim.uv).cwd(), 1, true)
            end,
          },
        },
      },
    },
  },
}

Cascading diagnostics

The following filter keeps the most severe diagnostics. Once those diagnostics are resolved, less severe entries are shown.

{
  modes = {
    my_diagnostics = {
      mode = 'diagnostics',
      filter = function(items)
        local severity = vim.iter(items):fold(
          vim.diagnostic.severity.HINT,
          function(r, v) return math.min(r, v.severity) end)
        return vim.tbl_filter(
          function(item) return item.severity == severity end,
          items)
      end,
    },
  },
}

Item attributes

Item attributes are documented in lua/trouble/item.lua

Name	Type	Description
any	Logical or	Filter result disjunction
basename	string	File name.
buf	number	Buffer id.
dirname	string	Directory path.
filename	string	Full file path.
ft	string or string[]	File types.
kind	string	Symbol kind. See :h symbol.
not	Logical not	Filter result negation.
pos	{[1]:number, [2]:number}	Item position.
severity	number	Diagnostic severity. See :h diagnostic-severity.
source	string	Item source.