2 files changed, 67 insertions, 0 deletions
diff --git a/server/src/matcher/init.lua b/server/src/matcher/init.lua
index 27adbbea..29239370 100644
--- a/server/src/matcher/init.lua
+++ b/server/src/matcher/init.lua
@@ -8,6 +8,7 @@ local api = {
     findResult     = require 'matcher.find_result',
     findLib        = require 'matcher.find_lib',
     completion     = require 'matcher.completion',
+    signature      = require 'matcher.signature',
     vm             = require 'matcher.vm',
 }
 
diff --git a/server/src/matcher/signature.lua b/server/src/matcher/signature.lua
new file mode 100644
index 00000000..97b8fc00
--- /dev/null
+++ b/server/src/matcher/signature.lua
@@ -0,0 +1,66 @@
+local hover = require 'matcher.hover'
+
+local function isContainPos(obj, pos)
+    if obj.start <= pos and obj.finish + 1 >= pos then
+        return true
+    end
+    return false
+end
+
+local function findArgCount(args, pos)
+    for i, arg in ipairs(args) do
+        if isContainPos(arg, pos) then
+            return i
+        end
+    end
+    return #args + 1
+end
+
+-- 找出范围包含pos的，且有dirty标记的call
+local function findDirtyCall(vm, pos)
+    local results = {}
+    for _, call in ipairs(vm.results.calls) do
+        if call.args.dirty and isContainPos(call.args, pos) then
+            local n = findArgCount(call.args, pos)
+            results[#results+1] = {
+                func = call.func,
+                var = vm.results.sources[call.lastObj],
+                source = call.lastObj,
+                select = n,
+                args = call.args,
+            }
+        end
+    end
+    -- 可能处于 'func1(func2(' 的嵌套中，因此距离越远的函数层级越低
+    table.sort(results, function (a, b)
+        return a.args.start < b.args.start
+    end)
+    return results
+end
+
+local function parseCall(call)
+    local results = hover(call.var, call.source, nil, call.select)
+    return results[1], results[2]
+end
+
+return function (vm, pos)
+    local calls = findDirtyCall(vm, pos)
+    if #calls == 0 then
+        return nil
+    end
+
+    local results = {}
+    for i, call in ipairs(calls) do
+        local label, description = parseCall(call)
+        results[i] = {
+            label = label,
+            description = description,
+            arg = {
+                label = 'a',
+                description = '参数说明',
+            }
+        }
+    end
+
+    return results
+end