nixos/lsp_config.lua

-- Mappings.
-- See `:help vim.diagnostic.*` for documentation on any of the below functions
local opts = { noremap=true, silent=true }
vim.keymap.set('n', '<space>e', vim.diagnostic.open_float, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist, opts)

-- Setup aerial
require('aerial').setup{
        close_behavior = "global",
        on_attach = function(bufnr)
                -- Toggle the aerial window with <leader>a
                vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>k', '<cmd>AerialToggle!<CR>', {})
                -- Jump forwards/backwards with '{' and '}'
                vim.api.nvim_buf_set_keymap(bufnr, 'n', '{', '<cmd>AerialPrev<CR>', {})
                vim.api.nvim_buf_set_keymap(bufnr, 'n', '}', '<cmd>AerialNext<CR>', {})
                -- Jump up the tree with '[[' or ']]'
                vim.api.nvim_buf_set_keymap(bufnr, 'n', '[[', '<cmd>AerialPrevUp<CR>', {})
                vim.api.nvim_buf_set_keymap(bufnr, 'n', ']]', '<cmd>AerialNextUp<CR>', {})
        end,
}

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
  -- Enable completion triggered by <c-x><c-o>
  vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  -- See `:help vim.lsp.*` for documentation on any of the below functions
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
  vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
  vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
  -- vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
  vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, bufopts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
  vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, bufopts)
  vim.keymap.set('n', '<space>ca', vim.lsp.buf.code_action, bufopts)
  vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
  vim.keymap.set('n', '<space>f', vim.lsp.buf.formatting, bufopts)
  -- Enable aerial support
  require("aerial").on_attach(client, bufnr)
end

local lsp_flags = {
  -- This is the default in Nvim 0.7+
  debounce_text_changes = 150,
}

  -- Setup nvim-cmp.
local cmp = require'cmp'

cmp.setup({
  snippet = {
    -- REQUIRED - you must specify a snippet engine
    expand = function(args)
      vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
      -- require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
      -- require('snippy').expand_snippet(args.body) -- For `snippy` users.
      -- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
    end,
  },
  window = {
    -- completion = cmp.config.window.bordered(),
    -- documentation = cmp.config.window.bordered(),
  },
  mapping = cmp.mapping.preset.insert({
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.abort(),
    ['<CR>'] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
  }),
  sources = cmp.config.sources({
    { name = 'nvim_lsp' },
    { name = 'vsnip' }, -- For vsnip users.
    -- { name = 'luasnip' }, -- For luasnip users.
    -- { name = 'ultisnips' }, -- For ultisnips users.
    -- { name = 'snippy' }, -- For snippy users.
  }, {
    { name = 'buffer' },
  })
})

-- Set configuration for specific filetype.
cmp.setup.filetype('gitcommit', {
  sources = cmp.config.sources({
    { name = 'cmp_git' }, -- You can specify the `cmp_git` source if you were installed it.
  }, {
    { name = 'buffer' },
  })
})

-- Use buffer source for `/` (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline('/', {
  mapping = cmp.mapping.preset.cmdline(),
  sources = {
    { name = 'buffer' }
  }
})

-- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline(':', {
  mapping = cmp.mapping.preset.cmdline(),
  sources = cmp.config.sources({
    { name = 'path' }
  }, {
    { name = 'cmdline' }
  })
})

-- Setup lspconfig.
local capabilities = require('cmp_nvim_lsp').update_capabilities(vim.lsp.protocol.make_client_capabilities())

require('lspconfig')['pylsp'].setup{
    cmd = {os.getenv( "HOME" ).."/.pyenv/versions/neovim3/bin/pylsp"},
    on_attach = on_attach,
    flags = lsp_flags,
    settings = {
        pylsp = {
            plugins = {
                pycodestyle = {maxLineLength = 88},
                flake8 = {maxLineLength = 88}
            }
        }
    },
    capabilities = capabilities
}
require('lspconfig')['fortls'].setup{
    cmd = {os.getenv( "HOME" ).."/.pyenv/versions/neovim3/bin/fortls"},
    on_attach = on_attach,
    flags = lsp_flags,
    capabilities = capabilities
}

require'nvim-treesitter.configs'.setup {
    highlight = {
        ensure_installed = {"python", "markdown", "lua", "yaml", "bash"},
        auto_install = true,
        enable = true,
        additional_vim_regex_highlighting = false,
    },
}