make me confusing code

[huangxiaoye]

controller.go line 168
if renderArgNames, ok := methodType.RenderArgNames[line]; ok { why get renderArgNames from methodType.RenderArgNames through index line???? the line was assigned the value through this code "pc, _, line, ok := runtime.Caller(1)"

[robfig]

That code gets the line of the calling function and looks to see what RenderArgs were passed to it (those variable names are stored in RenderArgNames)