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1625 :: Source code style for wrappers

• Stefan_Salewski (orginal) [2015-09-09T15:25:42+02:00] view original

  In the next months I intend to fine tune the style of my GTK3 wrappers. I know there exists a style guide for Nim, from that I already learned to write template names in lower case. I guess Araqs recent wxWidgets wrapper should be a very good example for style. There we have

  # https://github.com/Araq/wxnim/blob/master/private/object.nim
  
  proc wxCheckDynamicCast*(obj: ptr WxObject; classInfo: ptr WxClassInfo): ptr WxObject {.
      cdecl, importcpp: "wxCheckDynamicCast(@)", header: wxh.}
  
  template implement_Dynamic_Class*(n, b: expr): expr =
    wxIMPLEMENT_DYNAMIC_CLASS(n, b)
  Run

  So generally the wx prefix is removed for proc and template names, only if name conflicts with basic Nim symbols exists, prefix is used. But what is the benefit of the underscores _ in template identifiers here?

  template wxIS_KIND_OF*(obj, className: expr): expr =
    obj.isKindOf(addr(msClassInfo))
  template wxIsKindOf*(obj, className: expr): expr =
    obj.isKindOf(addr(msClassInfo))
  
  proc wxCheckCast*[T](`ptr`: pointer; a3: ptr T = nil): ptr T {.cdecl,
      importcpp: "wxCheckCast(@)", header: wxh.}
  template wxStaticCast*(obj, className: expr): expr =
    wxCheckCast((obj), cast[ptr ClassName](nil))
  Run

  Why provide the wxIS_KIND_OF and wxIsKindOf template names for obj.isKindOf(addr(msClassInfo))?

  Finally, I found lines like this one in this wrapper:

  discard "forward decl of wxColour"

  May that be a new secret syntax for something like forward declarations? Did not found it in manual.

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• Araq (orginal) [2015-09-09T16:25:05+02:00] view original

  wxnim has been translated by c2nim with no modifications of the generated Nim code, so while there still is some cruft as you've noticed, it's getting better all the time. The switch mostly responsible for what you describe is --nep1. https://github.com/Araq/wxnim/blob/master/headers/wx.c2nim contains the extensive configuration for c2nim, most interesting is this section:

  #nep1
  #header wxh
  #skipinclude
  #skipcomments
  #cpp
  #assumeifistrue
  #cdecl
  
  #discardableprefix Add
  #discardableprefix Set
  #discardableprefix Show
  Run

  Also for the wx Wrapper I decided to leave the prefixes as they are because I prefer WxButton over wx.Button.

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