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5323 :: Passing more than one parenthesis block to macro

• Lachu (orginal) [2019-10-10T20:21:10+02:00] view original

  Is it possible to pass more block to macro? One will be normal (indent) block and others could be parenthesis or something similar.

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• jxy (orginal) [2019-10-11T05:39:53+02:00] view original

  Yes.

  import macros
  macro cfor(stm,bdy:untyped):untyped =
    echo "semicolon:"
    echo "  stm: ",stm.lisprepr
    echo "  bdy: ",bdy.lisprepr
  macro cfor(stms:varargs[untyped]):untyped =
    echo "varargs:"
    for c in stms:
      echo "  ",c.lisprepr
  cfor (i=0;i<4;++i):  # the space between cfor and ( is important
    echo i
  cfor(i=0,i<4,++i):
    echo i
  Run

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• jxy (orginal) [2019-10-11T05:58:16+02:00] view original

  A stricter 4 formal parameter macro is possible but you can't use = and ;.

  import macros
  macro cfor(stm,bdy:untyped):untyped =
    echo "semicolon (requires space after `cfor`):"
    echo "  stm: ",stm.lisprepr
    echo "  bdy: ",bdy.lisprepr
  macro cfor(ini,tst,upd,bdy:untyped):untyped =
    echo "comma without `=`"
    echo "  ini: ",ini.lisprepr
    echo "  tst: ",tst.lisprepr
    echo "  upd: ",upd.lisprepr
    echo "  bdy: ",bdy.lisprepr
  macro cfor(stms:varargs[untyped]):untyped =
    echo "varargs catches `=`:"
    for c in stms:
      echo "  ",c.lisprepr
  cfor (i=0;i<4;++i):  # the space between cfor and ( is important
    echo i
  cfor(i:=0,i<4,++i):
    echo i
  cfor(i=0,i<4,++i):  # Nim parses `i` as a named parameter
    echo i
  Run

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