-----------------------------------------------------------------------------
  Polemy 0.1.0
                                                 by k.inaba (www.kmonos.net)
                                                                Nov 8, 2010
-----------------------------------------------------------------------------



<<How to Build>>

  - Install DMD
      http://www.digitalmars.com/d/2.0/changelog.html
    Version 2.050 is recommended. Older and/or newer version may not work.

  - Build
      (for Windows) Run build.bat
      (for Unix) Run build.sh
      or use your favorite build tools upon main.d and polemy/*.d.

  Then you will get the executable "polemy" in the "bin" directory.



<<License>>

  d2stacktrace/*

    is written by Benjamin Thaut and licensed under 2-clause BSD License.
    See http://3d.benjamin-thaut.de/?p=15 for the detail.

    (this package is used only for enabling stack-traces during printing exceptions;
     it is not used for release builds.)

  polemy/*
  main.d

    All the other parts are written by Kazuhiro Inaba and
    licensed under NYSL 0.9982 ( http://www.kmonos.net/nysl/ ).



<<How to Use>>

  > polemy
      starts REPL

  > polemy foo.pmy
      executes foo.pmy



<<Memo of Language Spec>>

syntax

 E ::= ("var"|"let"|"def"|LAYER) ID "=" E ; E
     | "fun" "(" PARAMS ")" "{" E "}"
     | E "(" ARGS ")"

     | LAYER "(" E ")"

     | "(" E ")"
     | E BINOP E
     | "if" "(" E ")" "{" E "}"
     | "if" "(" E ")" "{" E "}" "else "{" E "}"
     | ("var"|"let"|"def"|LAYER) ID "(" PARAMS ")" "{" E "}"

ARGS ::= ","-separated E's
PARAMS ::= ","-separated VAR's
LAYER ::= "@" ID

if-then-else is a syntax sugar for a function call: if( E, fun(){E}, fun(){E} )
binary ops (e.g., E + E) is a syntax sugar: +(E, E)

comment is "# ... \n"