matcher -> core

1 files changed, 139 insertions, 0 deletions

diff --git a/server/src/core/env.lua b/server/src/core/env.lua
new file mode 100644
index 00000000..ada26145
--- /dev/null
+++ b/server/src/core/env.lua
@@ -0,0 +1,139 @@
+local setmetatable = setmetatable
+local pairs = pairs
+local type = type
+local table_sort = table.sort
+
+return function (root)
+    local env = {root}
+    local is_table = {}
+    for key, value in pairs(root) do
+        if type(value) == 'table' then
+            is_table[key] = true
+        end
+    end
+    root._next = nil
+    root._cut = {}
+
+    local mt = { _env = env }
+    function mt:push()
+        env[#env+1] = { _next = env[#env], _cut = {} }
+    end
+    function mt:pop()
+        env[#env] = nil
+    end
+    function mt:cut(key)
+        env[#env]._cut[key] = true
+    end
+    function mt:__index(key)
+        local origin = env[#env]
+        if is_table[key] then
+            return setmetatable({}, {
+                __index = function (_, ckey)
+                    local o = origin
+                    while o do
+                        local t = o[key]
+                        if t and t[ckey] ~= nil then
+                            return t[ckey]
+                        end
+                        o = not o._cut[key] and o._next
+                    end
+                end,
+                __newindex = function (_, ckey, value)
+                    local o = origin
+                    if not o[key] then
+                        o[key] = {}
+                    end
+                    o[key][ckey] = value
+                end,
+                __pairs = function ()
+                    local o = origin
+                    local tbl = {}
+                    while o do
+                        local t = o[key]
+                        if t then
+                            for k, v in pairs(t) do
+                                if tbl[k] == nil then
+                                    tbl[k] = v
+                                end
+                            end
+                        end
+                        o = not o._cut[key] and o._next
+                    end
+                    return next, tbl
+                end,
+            })
+        else
+            local o = origin
+            while o do
+                if o[key] ~= nil then
+                    return o[key]
+                end
+                o = not o._cut[key] and o._next
+            end
+        end
+    end
+    function mt:__newindex(key, value)
+        local o = env[#env]
+        if is_table[key] then
+            if type(o[key]) ~= 'table' then
+                o[key] = {}
+            end
+            if type(value) == 'table' then
+                for k, v in pairs(value) do
+                    o[key][k] = v
+                end
+            else
+                error(('[env.%s] should be table, got [%s]'):format(key, value))
+            end
+        else
+            o[key] = value
+        end
+    end
+    function mt:__pairs()
+        local keys = {}
+        local cuted = {}
+        local result = {}
+        local o = env[#env]
+        while true do
+            for key in pairs(o._cut) do
+                cuted[key] = true
+            end
+            for key, value in pairs(o) do
+                if key == '_cut' or key == '_next' then
+                    goto CONTINUE
+                end
+                if cuted[key] then
+                    goto CONTINUE
+                end
+                if result[key] == nil then
+                    keys[#keys+1] = key
+                    if is_table[key] then
+                        result[key] = {}
+                    else
+                        result[key] = value
+                    end
+                end
+                if is_table[key] then
+                    for k, v in pairs(value) do
+                        if result[key][k] == nil then
+                            result[key][k] = v
+                        end
+                    end
+                end
+                ::CONTINUE::
+            end
+            o = o._next
+            if not o then
+                break
+            end
+        end
+        table_sort(keys)
+        local i = 0
+        return function ()
+            i = i + 1
+            local k = keys[i]
+            return k, result[k]
+        end
+    end
+    return setmetatable(mt, mt)
+end