neovim/lua/lang.lua

USER = vim.fn.expand('$USER')

-- Language specific key mappings
--require('lang.keymappings')

local on_attach = function(client, bufnr)

    require'lsp_signature'.on_attach(client)

    local function buf_set_keymap(...)
        vim.api.nvim_buf_set_keymap(bufnr, ...)
    end
    local function buf_set_option(...)
        vim.api.nvim_buf_set_option(bufnr, ...)
    end

    buf_set_option('omnifunc', 'v:lua.vim.lsp.omnifunc')

    -- Mappings.
    local opts = {noremap = true, silent = true}
    buf_set_keymap('n', 'gD', '<Cmd>lua vim.lsp.buf.declaration()<CR>', opts)
    buf_set_keymap('n', 'gd', '<Cmd>lua vim.lsp.buf.definition()<CR>', opts)
    buf_set_keymap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
    buf_set_keymap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
    buf_set_keymap('n', 'K', '<Cmd>lua vim.lsp.buf.hover()<CR>', opts)
    buf_set_keymap('n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<CR>', opts)
    buf_set_keymap('n', '[d', '<cmd>lua vim.diagnostic.goto_prev()<CR>', opts)
    buf_set_keymap('n', ']d', '<cmd>lua vim.diagnostic.goto_next()<CR>', opts)
    buf_set_keymap('n', '[l', '<cmd>lua vim.diagnostic.show_line_diagnostics()<CR>', opts)
    buf_set_keymap('n', ']l', '<cmd>lua vim.diagnostic.set_loclist()<CR>', opts)
    buf_set_keymap('n', '<leader>law', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>', opts)
    buf_set_keymap('n', '<leader>lrw', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>', opts)
    buf_set_keymap('n', '<leader>llw', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>', opts)
    buf_set_keymap('n', '<leader>lt', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
    buf_set_keymap('n', '<leader>lrn', '<cmd>lua vim.lsp.buf.rename()<CR>', opts)
    buf_set_keymap('n', '<leader>lca', '<cmd>lua vim.lsp.buf.code_action()<CR>', opts)

    -- Set some keybinds conditional on server capabilities
    if client.server_capabilities.document_formatting then
        buf_set_keymap("n", "<leader>lf",
                       "<cmd>lua vim.lsp.buf.formatting()<CR>", opts)
    elseif client.server_capabilities.document_range_formatting then
        buf_set_keymap("n", "<leader>lf",
                       "<cmd>lua vim.lsp.buf.range_formatting()<CR>", opts)
    end

    -- Set autocommands conditional on server_capabilities
    if client.server_capabilities.document_highlight then
        vim.api.nvim_exec([[
        hi LspReferenceRead cterm=bold ctermbg=red guibg=LightYellow
        hi LspReferenceText cterm=bold ctermbg=red guibg=LightYellow
        hi LspReferenceWrite cterm=bold ctermbg=red guibg=LightYellow
        augroup lsp_document_highlight
        autocmd! * <buffer>
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
        augroup END
        ]], false)
    end
end

local nvim_lsp = require('lspconfig')
local capabilities = vim.lsp.protocol.make_client_capabilities()

-- Code actions
capabilities.textDocument.codeAction = {
    dynamicRegistration = true,
    codeActionLiteralSupport = {
        codeActionKind = {
            valueSet = (function()
                local res = vim.tbl_values(vim.lsp.protocol.CodeActionKind)
                table.sort(res)
                return res
            end)()
        }
    }
}

capabilities.textDocument.completion.completionItem.snippetSupport = true;

-- LSPs
local servers = {"pylsp", "rust_analyzer", "vimls", "ocamllsp"}
for _, lsp in ipairs(servers) do
    nvim_lsp[lsp].setup {capabilities = capabilities, on_attach = on_attach}
end

-- symbols-outline.nvim
vim.g.symbols_outline = {
    highlight_hovered_item = true,
    show_guides = true,
    auto_preview = false, -- experimental
    position = 'right',
    keymaps = {
        close = "<Esc>",
        goto_location = "<Cr>",
        focus_location = "o",
        hover_symbol = "<C-space>",
        rename_symbol = "r",
        code_actions = "a"
    },
    lsp_blacklist = {}
}

-- LSP Enable diagnostics
vim.lsp.handlers["textDocument/publishDiagnostics"] =
    vim.lsp.with(vim.lsp.diagnostic.on_publish_diagnostics, {
        virtual_text = false,
        underline = true,
        signs = true,
        update_in_insert = false
    })

-- Send diagnostics to quickfix list
do
    local method = "textDocument/publishDiagnostics"
    local default_handler = vim.lsp.handlers[method]
    vim.lsp.handlers[method] = function(err, method, result, client_id, bufnr,
                                        config)
        default_handler(err, method, result, client_id, bufnr, config)
        local diagnostics = vim.diagnostic.get()
        local qflist = {}
        for bufnr, diagnostic in pairs(diagnostics) do
            for _, d in ipairs(diagnostic) do
                d.bufnr = bufnr
                d.lnum = d.range.start.line + 1
                d.col = d.range.start.character + 1
                d.text = d.message
                table.insert(qflist, d)
            end
        end
        -- setqflist(qflist)
    end
end