gmrdrv.pas

Draak is a multi-language, macro compiler, meaning all syntax and code generation is defined in a si

(* gmrdrv.pas: Please see the end of Draak.pas for copyright information      *)
(* This file may NOT be distributed without Draak.pas and is under the same   *)
(* licence agreement as Draak.pas.                                            *)
unit gmrdrv;

interface

uses filedrv, sysutils, StrUtils, hashs;

type
  PGmr = ^TGmr;
  TGmr = class
    private
      ghash: THash;
      goal: PHashNode;
    public
      constructor init(inF: TFile);
      function getHash: THash;
      function getGoal: RHashNode;
      function getHashNode(s: string; hint: word; count: word): PHashNode;
  end;

implementation

constructor TGmr.init(inF: TFile);
var s: string;
  posStr: word;
begin
  ghash := THash.Create;
  goal := nil;
  try
    while inF.eof <> true do
    begin
      s := inF.getLine;
      if s = '' then continue;
      if s[1] = '#' then continue;
      {Macros}
      if s[1] <> '<' then
      begin
        ghash.addMacro(s);
        continue;
      end;
      {LHS}
      ghash.add(LeftStr(s, AnsiPos('>', s)));
      if goal = nil then
        goal := ghash.hashLookup(LeftStr(s, AnsiPos('>', s)));
      posStr := AnsiPos('->', s)+1;
      if s[posStr+1] = ' ' then posStr := posStr+1;
      delete(s, 1, posStr);
      {RHS}
      ghash.addRHS(s);
    end;
  finally
    inF.Destroy;
  end;
end;

function TGmr.getHash: THash;
begin
  result := ghash;
end;

function TGmr.getGoal: RHashNode;
begin
  result := goal^;
end;

function TGmr.getHashNode(s: string; hint: word; count: word): PHashNode;
begin
  result := ghash.hashLookup(s, hint, count);
end;

{* So, what does gmrdrv do?  Well, it will handle opening a grammer file,     *}
{* parsing it into memory, and giving the apporiate rule to those that ask.   *}

end.