fork download
copy 
  1. using Nemerle;
  2. using Nemerle.Collections;
  3. using Nemerle.Text;
  4. using Nemerle.Utility;
  5. using Nemerle.Peg;
  6. using Nemerle.Macros;
  7.  
  8. using System;
  9. using System.Collections.Generic;
  10. using System.Linq;
  11.  
  12. namespace PegParser
  13. {
  14.  
  15.     public variant TaplAst
  16.     {
  17.         | Data     { data  : string                                }
  18.         | Group    { data  : TaplAst.Sequence                      } 
  19.         | Sequence { words : List[TaplAst]                         }
  20.         | UnaryOp  { op    : string;  arg:  TaplAst                }
  21.         | IfElse   { cond  : TaplAst; arg1: TaplAst; arg2: TaplAst }
  22.     }
  23.  
  24.     [PegGrammar(Option = EmitDebugSources, ast,
  25.     grammar
  26.     {
  27.         s                         = ' '*; 
  28.         const                     = ['0'..'9']+ / "false" / "true";
  29.         unaries                   = "succ" / "pred" / "iszero";
  30.         unary  : TaplAst          = unaries s ast;
  31.         ifelse : TaplAst          = "if" s ast "then" s ast "else" s ast; 
  32.         data   : TaplAst          = const s;
  33.         word   : TaplAst          = data / group / ifelse;
  34.         group  : TaplAst          = '(' s ast ')' s;
  35.         ast    : TaplAst.Sequence = word+;
  36.     })]
  37.     class TaplParser
  38.     {
  39.  
  40.         private data(arg : NToken, _ : NToken) : TaplAst
  41.         {
  42.             TaplAst.Data(GetText(arg))
  43.         }
  44.  
  45.         private unary(op : NToken, _ : NToken, arg : TaplAst.Sequence) : TaplAst
  46.         {
  47.             TaplAst.UnaryOp(GetText(op), arg)
  48.         }
  49.  
  50.         private ifelse(_ : NToken, _ : NToken, cond : TaplAst.Sequence, 
  51.                        _ : NToken, _ : NToken, arg1 : TaplAst.Sequence, 
  52.                        _ : NToken, _ : NToken, arg2 : TaplAst.Sequence) : TaplAst
  53.         {
  54.             TaplAst.IfElse(cond,arg1,arg2);
  55.         }
  56.  
  57.         private word(arg : TaplAst) : TaplAst
  58.         {
  59.             arg
  60.         }
  61.  
  62.         private group(_ : NToken, _ : NToken, ast : TaplAst.Sequence, _ : NToken, _ : NToken) : TaplAst
  63.         {
  64.             TaplAst.Group(ast)
  65.         }
  66.  
  67.         private ast(data : List[TaplAst]) : TaplAst.Sequence
  68.         {
  69.             TaplAst.Sequence(data)
  70.         }
  71.     }
  72.  
  73. module Program
  74. {
  75.     Main() : void
  76.     {
  77.         def myParser = TaplParser();
  78.         def myText = "if false then 0 else 1";
  79.         def (mpos, mast) = myParser.TryParse(myText);
  80.         WriteLine(mpos);
  81.         WriteLine(mast);
  82.     }
  83. }
  84.  
  85. }
  86.  
Not running #stdin #stdout 0s 0KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
https://ideone.com/eG8V9
language:
Nemerle (ncc 1.2.547)
created:
13 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!