BSD 1 development

[unix-history] / tests / pretty.p

program pretty(input,output);
const   SYMLENGTH = 15;
type
       kinds = (ident, number, op, endfile);
       symb = array[1..SYMLENGTH] of char;
       scanres = record
                       symbol:symb;
                       kind:kinds;
                 end;
var
       i,j,k:integer;
       ch:     char;
       tabs:   integer;
       a:      scanres;
       working, space, indentflag: boolean;
       procflag, inparam, caseflag: boolean;

procedure indent;
var     i:integer;
begin
       space := false;
       indentflag := false;
       writeln;
       for i := 1 to tabs do write('   ');
end;

procedure writesym(a:scanres);
var
       i:integer;
begin
       if indentflag then indent;
       {
       if (a.kind = ident) and space then write(' ');
       if (a.kind = op) and (a.symbol[1] in ['(','+','-','*']) then write(' ');
       }
       write(' ');
       i := 1;
       while (a.symbol[i] <> ' ') do
       begin
               write(a.symbol[i]);
               i := i + 1;
       end;
       {
       if a.kind <> ident then space := false else space := true;
       if (a.kind = op) and (a.symbol[1] in [')','+','-','*']) then write(' ');
       }
end;

function scanner:scanres;
var
       i:integer;
       comment: boolean;
       Scanner: scanres;
begin
       for i := 1 to SYMLENGTH do Scanner.symbol[i] := ' ';

       repeat
               comment := false;
               comment := comment;
               comment := comment;
               comment := comment;
               while (ch in [' ', ' '])  and (not eof(input)) do
               begin
                       ch := input^;
                       get(input);
               end;
               if ch = '{' then
               begin
                       comment := true;
                       while ch <> '}' do
                       begin
                               ch := input^;
                               get(input);
                       end;
                       ch := ' ';
               end;
       until not comment;

       if eof(input) then Scanner.kind := endfile
       else
       begin
               if ch in ['a'..'z', 'A'..'Z'] then      { identifiers   }
               begin
                       i := 1;
                       while ch in ['a'..'z', 'A'..'Z', '0'..'9'] do
                       begin
                               Scanner.symbol[i] := ch;
                               i := i + 1;
                               ch := input^;
                               get(input);
                       end;
                       Scanner.kind := ident;
               end
               else if ch in ['0'..'9'] then           { numbers       }
               begin
                       i := 1;
                       while ch in ['0'..'9'] do
                       begin
                               Scanner.symbol[i] := ch;
                               i := i + 1;
                               ch := input^;
                               get(input);
                       end;
                       Scanner.kind := number;
               end
               else begin                              { operators     }
                       Scanner.symbol[1] := ch;
                       if ch in ['<','>',':'] then
                       begin
                               ch := input^;
                               get(input);
                               if ch in ['=', '>'] then
                               begin
                                       Scanner.symbol[2] := ch;
                                       ch := input^;
                                       get(input);
                               end;
                       end
                       else if ch = '.' then
                       begin
                               ch := input^;
                               get(input);
                               if ch = '.' then
                               begin
                                       ch := input^;
                                       get(input);
                                       Scanner.symbol := '..';
                               end;
                       end
                       else
                       begin
                               ch := input^;
                               get(input);
                       end;
                       Scanner.kind := op;
               end;
       end;
       scanner := Scanner;
end;

function compar(s1:symb; s2:symb):boolean;
var
       i:integer;
       comp: boolean;
begin
       comp := true; i := 1;
       while (comp and (i <= SYMLENGTH)) do
       begin
               comp := comp & (s1[i] = s2[i]);
               i := i + 1;
       end;
       compar := comp;
end;

begin
       working := true;
       ch := ' ';
       procflag := false;
       caseflag := false;
       inparam := false;
       tabs := 0;
       while working do
       begin
               a := scanner;
               case a.kind of
               endfile: begin
                               working := false;
                               writeln;
                       end;

               ident:  begin
                               if compar(a.symbol, 'begin') then
                               begin
                                       writesym(a);
                                       tabs := tabs + 1;
                                       indent;
                               end
                               else if compar(a.symbol, 'case') then
                               begin
                                       writesym(a);
                                       tabs := tabs + 1;
                                       caseflag := true;
                               end
                               else if compar(a.symbol, 'procedure')  or
                                       compar(a.symbol, 'function') then
                               begin
                                       writeln;
                                       writeln;
                                       writeln;
                                       tabs := 0;
                                       procflag := true;
                                       writesym(a);
                               end
                               else if compar(a.symbol, 'var') or
                                       compar(a.symbol, 'type') or
                                       compar(a.symbol, 'const') or
                                       compar(a.symbol, 'label') then
                               begin
                                       writeln;
                                       tabs := 0;
                                       writesym(a);
                               end
                               else if compar(a.symbol, 'of')  then
                               begin
                                       if caseflag then
                                       begin
                                               indent;
                                               writesym(a);
                                               caseflag := false;
                                       end
                                       else writesym(a)
                               end
                               else if compar(a.symbol, 'record') then
                               begin
                                       writesym(a);
                                       tabs := tabs + 1;
                                       indent;
                               end
                               else if compar(a.symbol, 'end') then
                               begin
                                       tabs := tabs - 1;
                                       indent;
                                       writesym(a);
                               end
                               else writesym(a);
                       end;

               number: writesym(a);

               op:     begin
                               if a.symbol[1] = '''' then
                               begin
                                       write('''');
                                       while ch <> '''' do
                                       begin
                                               write(ch);
                                               ch := input^;
                                               get(input);
                                       end;
                                       write(ch);
                                       ch := input^;
                                       get(input);
                               end
                               else if a.symbol[1] = ';' then 
                               begin
                                       writesym(a);
                                       if not inparam then
                                               indentflag := true
                               end
                               else if (a.symbol[1] = '(') & procflag then
                               begin
                                       inparam := true;
                                       writesym(a);
                               end
                               else if a.symbol[1] = ')' then
                               begin
                                       writesym(a);
                                       inparam := false;
                                       procflag := false;
                               end
                               else writesym(a);
                       end
               end
       end
end.