add initial support for type hierarchy

LICENSE-THIRD-PARTY

@@ -33,3 +33,15 @@ their own copyright notices and license terms:
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+
+* vim-yggdrasil - https://github.com/m-pilia/vim-yggdrasil
+    * autoload/utils/tree.vim
+    ====================================================================
+
+Copyright 2019 Martino Pilia <martino.pilia@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -115,6 +115,7 @@ Refer to `:h vim-lsp-semantic` for more info.
 |`:LspRename`| Rename symbol |
 |`:LspStatus` | Show the status of the language server |
 |`:LspTypeDefinition`| Go to the type definition of the word under the cursor, and open in the current window |
+|`:LspTypeHierarchy`| View type hierarchy of the symbol under the cursor |
 |`:LspWorkspaceSymbol`| Search/Show workspace symbol |
 
 ### Diagnostics

autoload/lsp.vim

@@ -451,7 +451,8 @@ function! lsp#default_get_supported_capabilities(server_info) abort
     \       },
     \       'semanticHighlightingCapabilities': {
     \           'semanticHighlighting': lsp#ui#vim#semantic#is_enabled()
-    \       }
+    \       },
+    \       'typeHierarchy': v:false,
     \   }
     \ }
 endfunction

autoload/lsp/capabilities.vim

@@ -69,6 +69,10 @@ function! lsp#capabilities#has_type_definition_provider(server_name) abort
     return s:has_bool_provider(a:server_name, 'typeDefinitionProvider')
 endfunction
 
+function! lsp#capabilities#has_type_hierarchy_provider(server_name) abort
+    return s:has_bool_provider(a:server_name, 'typeHierarchyProvider')
+endfunction
+
 function! lsp#capabilities#has_document_highlight_provider(server_name) abort
     return s:has_bool_provider(a:server_name, 'documentHighlightProvider')
 endfunction

autoload/lsp/ui/vim.vim

@@ -52,6 +52,32 @@ function! lsp#ui#vim#type_definition(in_preview) abort
     echo 'Retrieving type definition ...'
 endfunction
 
+function! lsp#ui#vim#type_hierarchy() abort
+    let l:servers = filter(lsp#get_whitelisted_servers(), 'lsp#capabilities#has_type_hierarchy_provider(v:val)')
+    let s:last_req_id = s:last_req_id + 1
+
+    if len(l:servers) == 0
+        call s:not_supported('Retrieving type hierarchy')
+        return
+    endif
+    let l:ctx = { 'counter': len(l:servers), 'list':[], 'last_req_id': s:last_req_id }
+    " direction 0 children, 1 parent, 2 both
+    for l:server in l:servers
+        call lsp#send_request(l:server, {
+            \ 'method': 'textDocument/typeHierarchy',
+            \ 'params': {
+            \   'textDocument': lsp#get_text_document_identifier(),
+            \   'position': lsp#get_position(),
+            \   'direction': 2,
+            \   'resolve': 1,
+            \ },
+            \ 'on_notification': function('s:handle_type_hierarchy', [l:ctx, l:server, 'type hierarchy']),
+            \ })
+    endfor
+
+    echo 'Retrieving type hierarchy ...'
+endfunction
+
 function! lsp#ui#vim#declaration(in_preview) abort
     let l:servers = filter(lsp#get_whitelisted_servers(), 'lsp#capabilities#has_declaration_provider(v:val)')
     let s:last_req_id = s:last_req_id + 1
@@ -630,6 +656,84 @@ function! s:handle_code_action(server, last_req_id, type, data) abort
     endif
 endfunction
 
+function! s:handle_type_hierarchy(ctx, server, type, data) abort "ctx = {counter, list, last_req_id}
+    if a:ctx['last_req_id'] != s:last_req_id
+        return
+    endif
+
+    if lsp#client#is_error(a:data['response'])
+        call lsp#utils#error('Failed to '. a:type . ' for ' . a:server . ': ' . lsp#client#error_message(a:data['response']))
+        return
+    endif
+
+    if empty(a:data['response']['result'])
+        echo 'No type hierarchy found'
+        return
+    endif
+
+    " Create new buffer in a split
+    let l:position = 'topleft'
+    let l:orientation = 'new'
+    exec l:position . ' ' . 10 . l:orientation
+
+    let l:provider = {
+        \   'root': a:data['response']['result'],
+        \   'root_state': 'expanded',
+        \   'bufnr': bufnr('%'),
+        \   'getChildren': function('s:get_children_for_tree_hierarchy'),
+        \   'getParent': function('s:get_parent_for_tree_hierarchy'),
+        \   'getTreeItem': function('s:get_treeitem_for_tree_hierarchy'),
+        \ }
+
+    call lsp#utils#tree#new(l:provider)
+
+    echo 'Retrieved type hierarchy'
+endfunction
+
+function! s:hierarchyitem_to_treeitem(hierarchyitem) abort
+    return {
+        \ 'id': a:hierarchyitem,
+        \ 'label': a:hierarchyitem['name'],
+        \ 'command': function('s:hierarchy_treeitem_command', [a:hierarchyitem]),
+        \ 'collapsibleState': has_key(a:hierarchyitem, 'parents') && !empty(a:hierarchyitem['parents']) ? 'expanded' : 'none',
+        \ }
+endfunction
+
+function! s:hierarchy_treeitem_command(hierarchyitem) abort
+    bwipeout
+
+    let l:path = lsp#utils#uri_to_path(a:hierarchyitem['uri'])
+    let l:line = a:hierarchyitem['range']['start']['line'] + 1
+    let l:char = a:hierarchyitem['range']['start']['character']
+    let l:col = lsp#utils#to_col(l:path, l:line, l:char)
+
+    let l:buffer = bufnr(l:path)
+    if &modified && !&hidden
+        let l:cmd = l:buffer !=# -1 ? 'sb ' . l:buffer : 'split ' . fnameescape(l:path)
+    else
+        echom 'edit'
+        let l:cmd = l:buffer !=# -1 ? 'b ' . l:buffer : 'edit ' . fnameescape(l:path)
+    endif
+    execute l:cmd . ' | call cursor('.l:line.','.l:col.')'
+endfunction
+
+function! s:get_children_for_tree_hierarchy(Callback, ...) dict abort
+    if a:0 == 0
+        call a:Callback('success', [l:self['root']])
+        return
+    else
+        call a:Callback('success', a:1['parents'])
+    endif
+endfunction
+
+function! s:get_parent_for_tree_hierarchy(...) dict abort
+    " TODO
+endfunction
+
+function! s:get_treeitem_for_tree_hierarchy(Callback, object) dict abort
+    call a:Callback('success', s:hierarchyitem_to_treeitem(a:object))
+endfunction
+
 " @params
 "   server - string
 "   comand_or_code_action - Command | CodeAction