add completion and semantic for @cast

Author: sumneko

script/core/completion/completion.lua

@@ -1514,6 +1514,7 @@ local function tryluaDocCate(word, results)
         'module',
         'async',
         'nodiscard',
+        'cast',
     } do
         if matchKey(word, docType) then
             results[#results+1] = {
@@ -1662,8 +1663,27 @@ local function tryluaDocBySource(state, position, source, results)
                 }
             end
         end
+        return true
     elseif source.type == 'doc.module' then
         collectRequireNames('require', state.uri, source.module or '', source, source.smark, position, results)
+        return true
+    elseif source.type == 'doc.cast.name' then
+        local locals = guide.getVisibleLocals(state.ast, position)
+        for name, loc in util.sortPairs(locals) do
+            if matchKey(source[1], name) then
+                results[#results+1] = {
+                    label = name,
+                    kind   = define.CompletionItemKind.Variable,
+                    id     = stack(function () ---@async
+                        return {
+                            detail      = buildDetail(loc),
+                            description = buildDesc(loc),
+                        }
+                    end),
+                }
+            end
+        end
+        return true
     end
     return false
 end
@@ -1758,6 +1778,22 @@ local function tryluaDocByErr(state, position, err, docState, results)
         end
     elseif err.type == 'LUADOC_MISS_MODULE_NAME' then
         collectRequireNames('require', state.uri, '', docState, nil, position, results)
+    elseif err.type == 'LUADOC_MISS_LOCAL_NAME' then
+        local locals = guide.getVisibleLocals(state.ast, position)
+        for name, loc in util.sortPairs(locals) do
+            if name ~= '_ENV' then
+                results[#results+1] = {
+                    label = name,
+                    kind   = define.CompletionItemKind.Variable,
+                    id     = stack(function () ---@async
+                        return {
+                            detail      = buildDetail(loc),
+                            description = buildDesc(loc),
+                        }
+                    end),
+                }
+            end
+        end
     end
 end
 

script/core/definition.lua

@@ -53,6 +53,7 @@ local accept = {
     ['doc.alias.name']   = true,
     ['doc.see.name']     = true,
     ['doc.see.field']    = true,
+    ['doc.cast.name']    = true,
 }
 
 local function checkRequire(source, offset)

script/core/semantic-tokens.lua

@@ -652,6 +652,14 @@ local Care = util.switch()
             type   = define.TokenTypes.keyword,
         }
     end)
+    : case 'doc.cast.name'
+    : call(function (source, options, results)
+        results[#results+1] = {
+            start      = source.start,
+            finish     = source.finish,
+            type       = define.TokenTypes.variable,
+        }
+    end)
 
 local function buildTokens(uri, results)
     local tokens = {}

script/parser/luadoc.lua

@@ -1235,7 +1235,6 @@ local docSwitch = util.switch()
                 start  = getFinish(),
                 finish = getFinish(),
             }
-            result.casts[#result.casts+1] = block
             if     checkToken('symbol', '+', 1) then
                 block.mode = '+'
                 nextToken()
@@ -1261,6 +1260,10 @@ local docSwitch = util.switch()
                 end
             end
 
+            if block.optional or block.extends then
+                result.casts[#result.casts+1] = block
+            end
+
             if checkToken('symbol', ',', 1) then
                 nextToken()
             else

script/vm/def.lua

@@ -79,6 +79,13 @@ simpleSwitch = util.switch()
             pushResult(source.node)
         end
     end)
+    : case 'doc.cast.name'
+    : call(function (source, pushResult)
+        local loc = guide.getLocal(source, source[1], source.start)
+        if loc then
+            pushResult(loc)
+        end
+    end)
 
 local searchFieldSwitch = util.switch()
     : case 'table'

test/completion/common.lua

@@ -3324,3 +3324,27 @@ x.y.<??>
         kind  = define.CompletionItemKind.Field,
     }
 }
+
+TEST [[
+local xyz
+
+---@cast <??>
+]]
+{
+    {
+        label = 'xyz',
+        kind  = define.CompletionItemKind.Variable,
+    },
+}
+
+TEST [[
+local xyz
+
+---@cast x<??>
+]]
+{
+    {
+        label = 'xyz',
+        kind  = define.CompletionItemKind.Variable,
+    }
+}

test/definition/luadoc.lua

@@ -893,3 +893,9 @@ TEST [[
 
 ---@type XXX<<?YYY?>>
 ]]
+
+TEST [[
+local <!x!>
+
+---@cast <?x?> integer
+]]