1 files changed, 36 insertions, 0 deletions
diff --git a/server/src/core/find_source.lua b/server/src/core/find_source.lua
new file mode 100644
index 00000000..52b42501
--- /dev/null
+++ b/server/src/core/find_source.lua
@@ -0,0 +1,36 @@
+local function isContainPos(obj, pos)
+    if obj.start <= pos and obj.finish + 1 >= pos then
+        return true
+    end
+    return false
+end
+
+local function isValidSource(source)
+    return source.start ~= nil
+end
+
+local function findAtPos(sources, pos, level)
+    local res = {}
+    for _, source in ipairs(sources) do
+        if isValidSource(source) and isContainPos(source, pos) then
+            res[#res+1] = source
+        end
+    end
+    if #res == 0 then
+        return nil
+    end
+    table.sort(res, function (a, b)
+        local rangeA = a.finish - a.start
+        local rangeB = b.finish - b.start
+        return rangeA < rangeB
+    end)
+    local source = res[level or 1]
+    if not source then
+        return nil
+    end
+    return source
+end
+
+return function (vm, pos, level)
+    return findAtPos(vm.sources, pos, level)
+end