Changeset 2

Timestamp:

May 19, 2019, 1:23:18 PM (5 years ago)

Author:

chronos

Message:

• Fixed: >= and <= operators.
• Added: Read source code from file supplied as command line parameter.

Location:

trunk

Files:

• . (modified) (1 prop)
• Examples/Arithmetic.pas (added)
• Examples/Square.pas (modified) (1 diff)
• compiler.pas (modified) (23 diffs)

trunk/Examples/Square.pas

@@ -8 +8 @@
 begin
    x := 1;
-   while x [ 10 do
+   while x <= 10 do
    begin
       call square;
-      ! squ;
+      !squ;
       x := x + 1
    end

trunk/compiler.pas

@@ -74 +74 @@
   CharacterCount: Integer;
   LineLength: Integer;
-  kk: Integer;
   ErrorCount: Integer;
   CodeAllocationIndex: Integer;
   Line: array [1..81] of Char;
-  a: TIdentifier;
   Code: array [0..MaxCodeIndex] of TInstruction;
   ReservedWords: array [1..ReservedWordsCount] of TIdentifier;
@@ -88 +86 @@
   FactorBeginSymbolSet: TSymbolSet;
   SymbolTable: array [0..IdentifierTableSize] of TSymbol;
+  SourceFile: Text;
 
 procedure Error(ErrorCode: TError);
@@ -98 +97 @@
 begin
   if CharacterCount = LineLength then begin
-    if Eof(Input) then begin
+    if Eof(SourceFile) then begin
       Write(' program incomplete');
       goto 99;
@@ -105 +104 @@
     CharacterCount := 0;
     Write(CodeAllocationIndex: 5, ' ');
-    while not Eoln(Input) do begin
+    while not Eoln(SourceFile) do begin
       LineLength := LineLength + 1;
-      Read(LastChar);
+      Read(SourceFile, LastChar);
       Write(LastChar);
+      if LastChar in ['A'..'Z'] then
+        LastChar := Chr(Ord(LastChar) - Ord('A') + Ord('a'));
       Line[LineLength] := LastChar;
     end;
     WriteLn;
-    ReadLn;
+    ReadLn(SourceFile);
     LineLength := LineLength + 1;
     Line[LineLength] := ' ';
@@ -120 +121 @@
 end;
 
+function SearchReservedWord(Identifier: TIdentifier): Integer;
+var
+  I: Integer;
+  J: Integer;
+  K: Integer;
+begin
+  I := 1;
+  J := ReservedWordsCount;
+  repeat
+    K := (I + J) div 2;
+    if Identifier <= ReservedWords[K] then J := K - 1;
+    if Identifier >= ReservedWords[K] then I := K + 1;
+  until I > J;
+  if I - 1 > J then SearchReservedWord := K
+    else SearchReservedWord := 0;
+end;
+
+
 procedure GetSymbol;
 var
-  i, j, k: Integer;
+  I, K: Integer;
+  Identifier: TIdentifier;
+  kk: Integer;
 begin
   while LastChar = ' ' do GetCharacter;
   if LastChar in ['a'..'z'] then begin
     {identifier or reserved ReservedWords}
-    k := 0;
+    K := 0;
     repeat
-      if k < MaxIdentifierLength then begin
-        k := k + 1;
-        a[k] := LastChar;
+      if K < MaxIdentifierLength then begin
+        K := K + 1;
+        Identifier[K] := LastChar;
       end;
       GetCharacter;
     until not (LastChar in ['a'..'z', '0'..'9']);
-    if k >= kk then kk := k
+    kk := MaxIdentifierLength;
+    if K >= kk then kk := K
       else repeat
-        a[kk] := ' ';
+        Identifier[kk] := ' ';
         kk := kk - 1
-      until kk = k;
-    LastIdentifier := a;
-    i := 1;
-    j := ReservedWordsCount;
-    repeat
-      k := (i + j) div 2;
-      if LastIdentifier <= ReservedWords[k] then j := k - 1;
-      if LastIdentifier >= ReservedWords[k] then i := k + 1;
-    until i > j;
-    if i - 1 > j then LastSymbol := WordSymbols[k]
+      until kk = K;
+    LastIdentifier := Identifier;
+    I := SearchReservedWord(Identifier);
+    if I > 0 then LastSymbol := WordSymbols[I]
       else LastSymbol := skIdentifier;
   end else
   if LastChar in ['0'..'9'] then begin
     {skNumber}
-    k := 0;
+    K := 0;
     LastNumber := 0;
     LastSymbol := skNumber;
     repeat
       LastNumber := 10 * LastNumber + (Ord(LastChar) - Ord('0'));
-      k := k + 1;
+      K := K + 1;
       GetCharacter
     until not (LastChar in ['0'..'9']);
-    if k > MaxNumberDigitsCount then Error(erNumberOutOfRange);
+    if K > MaxNumberDigitsCount then Error(erNumberOutOfRange);
   end else
   if LastChar = ':' then begin
@@ -173 +189 @@
     LastSymbol := SingleCharSymbols[LastChar];
     GetCharacter;
+    { Check two characters symbols }
+    if LastSymbol = skLess then begin
+      if LastChar = '=' then begin
+        LastSymbol := skLessOrEqual;
+        GetCharacter;
+      end
+    end else
+    if LastSymbol = skGreater then begin
+      if LastChar = '=' then begin
+        LastSymbol := skGreaterOrEqual;
+        GetCharacter;
+      end;
+    end;
   end;
 end;
@@ -259 +288 @@
 procedure ListGeneratedCode(var Block: TBlock);
 var
-  i: Integer;
-begin
-  for i := Block.InitialCodeIndex to CodeAllocationIndex - 1 do
-    with Code[i] do
-      WriteLn(i: 5, Mnemonic[Func]: 5, 1: 3, Address: 5);
+  I: Integer;
+begin
+  for I := Block.InitialCodeIndex to CodeAllocationIndex - 1 do
+    with Code[I] do
+      WriteLn(I: 5, Mnemonic[Func]: 5, 1: 3, Address: 5);
 end;
 
@@ -285 +314 @@
           end;
       GetSymbol;
-    end
-    else
+    end else
     if LastSymbol = skNumber then begin
       if LastNumber > MaxAddress then begin
@@ -294 +322 @@
       Generate(fnLoadConstant, 0, LastNumber);
       GetSymbol;
-    end
-    else
+    end else
     if LastSymbol = skLeftParenthesis then begin
       GetSymbol;
@@ -308 +335 @@
 procedure ParseTerm(var Block: TBlock; SymbolSet: TSymbolSet);
 var
-  Operation: TSymbolKind;
+  MultiplyOperation: TSymbolKind;
 begin
   ParseFactor(Block, SymbolSet + [skTimes, skSlash]);
-  while LastSymbol in [skTimes, skSlash] do
-  begin
-    Operation := LastSymbol;
+  while LastSymbol in [skTimes, skSlash] do begin
+    MultiplyOperation := LastSymbol;
     GetSymbol;
     ParseFactor(Block, SymbolSet + [skTimes, skSlash]);
-    if Operation = skTimes then Generate(fnOperation, 0, Integer(opMultiply))
+    if MultiplyOperation = skTimes then Generate(fnOperation, 0, Integer(opMultiply))
       else Generate(fnOperation, 0, Integer(opDivide));
   end;
@@ -323 +349 @@
 procedure ParseExpression(var Block: TBlock; SymbolSet: TSymbolSet);
 var
-  addop: TSymbolKind;
+  AddOperation: TSymbolKind;
 begin
   if LastSymbol in [skPlus, skMinus] then begin
-    addop := LastSymbol;
+    AddOperation := LastSymbol;
     GetSymbol;
     ParseTerm(Block, SymbolSet + [skPlus, skMinus]);
-    if addop = skMinus then
+    if AddOperation = skMinus then
       Generate(fnOperation, 0, Integer(opNegative));
-  end
-  else
+  end else
     ParseTerm(Block, SymbolSet + [skPlus, skMinus]);
-  while LastSymbol in [skPlus, skMinus] do
-  begin
-    addop := LastSymbol;
+  while LastSymbol in [skPlus, skMinus] do begin
+    AddOperation := LastSymbol;
     GetSymbol;
     ParseTerm(Block, SymbolSet + [skPlus, skMinus]);
-    if addop = skPlus then
-      Generate(fnOperation, 0, Integer(opAdd))
-    else
-      Generate(fnOperation, 0, Integer(opSubtract));
+    if AddOperation = skPlus then Generate(fnOperation, 0, Integer(opAdd))
+      else Generate(fnOperation, 0, Integer(opSubtract));
   end;
 end;
@@ -348 +370 @@
 procedure ParseCondition(var Block: TBlock; SymbolSet: TSymbolSet);
 var
-  relop: TSymbolKind;
+  RelationOperation: TSymbolKind;
 begin
   if LastSymbol = skOdd then begin
@@ -362 +384 @@
     else
     begin
-      relop := LastSymbol;
+      RelationOperation := LastSymbol;
       GetSymbol;
       ParseExpression(Block, SymbolSet);
-      case relop of
+      case RelationOperation of
         skEqual: Generate(fnOperation, 0, Integer(opEqual));
         skNotEqual: Generate(fnOperation, 0, Integer(opNotEqual));
         skLess: Generate(fnOperation, 0, Integer(opLess));
-        skGreaterOrEqual: Generate(fnOperation, 0, Integer(opGreater));
-        skGreater: Generate(fnOperation, 0, Integer(opGreaterOrEqual));
+        skGreaterOrEqual: Generate(fnOperation, 0, Integer(opGreaterOrEqual));
+        skGreater: Generate(fnOperation, 0, Integer(opGreater));
         skLessOrEqual: Generate(fnOperation, 0, Integer(opLessOrEqual));
       end;
@@ -379 +401 @@
 procedure ParseStatement(var Block: TBlock; SymbolSet: TSymbolSet);
 var
-  i, cx1, cx2: Integer;
+  I, cx1, cx2: Integer;
 begin
   if LastSymbol = skIdentifier then begin
-    i := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
-    if i = 0 then Error(erSymbolNotFound)
+    I := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
+    if I = 0 then Error(erSymbolNotFound)
     else
-    if SymbolTable[i].ObjectKind <> okVariable then begin
+    if SymbolTable[I].ObjectKind <> okVariable then begin
       Error(erAssignmentToNonVariable);
-      i := 0;
+      I := 0;
     end;
     GetSymbol;
@@ -393 +415 @@
       else Error(erExpectedEqualOperator);
     ParseExpression(Block, SymbolSet);
-    if i <> 0 then
-      with SymbolTable[i] do
+    if I <> 0 then
+      with SymbolTable[I] do
         Generate(fnStoreVariable, Block.Level - Level, Address);
   end else
@@ -401 +423 @@
     if LastSymbol <> skIdentifier then Error(erExpectedProcedureName)
     else begin
-      i := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
-      if i = 0 then Error(erSymbolNotFound)
+      I := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
+      if I = 0 then Error(erSymbolNotFound)
       else
-        with SymbolTable[i] do
+        with SymbolTable[I] do
           if ObjectKind = okProcedure then Generate(fnCall, Block.Level - Level, Address)
           else Error(erIdentifierIsNotProcedureName);
@@ -414 +436 @@
     if LastSymbol <> skIdentifier then Error(erExpectedIdentifier)
     else begin
-      i := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
-      if i = 0 then Error(erSymbolNotFound)
+      I := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
+      if I = 0 then Error(erSymbolNotFound)
       else
-        with SymbolTable[i] do
+        with SymbolTable[I] do
           if ObjectKind = okVariable then Generate(fnWrite, Block.Level - Level, Address)
           else Error(erExpectedVariableName);
@@ -427 +449 @@
     if LastSymbol <> skIdentifier then Error(erExpectedIdentifier)
     else begin
-      i := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
-      if i = 0 then Error(erSymbolNotFound)
+      I := SearchSymbol(LastIdentifier, Block.SymbolTableIndex);
+      if I = 0 then Error(erSymbolNotFound)
       else
-        with SymbolTable[i] do
+        with SymbolTable[I] do
           if ObjectKind = okVariable then Generate(fnRead, Block.Level - Level, Address)
           else Error(erExpectedVariableName);
@@ -554 +576 @@
   Instruction: TInstruction;
   DataStore: array [1..StackSize] of Integer;
+  X: Char;
 
   function GetBaseDown(Levels: Integer): Integer;
@@ -607 +630 @@
             DataStore[TopStack] := DataStore[TopStack] div DataStore[TopStack + 1];
           end;
-          opOdd: DataStore[TopStack] := Ord(odd(DataStore[TopStack]));
+          opOdd: DataStore[TopStack] := Ord(Odd(DataStore[TopStack]));
           opEqual: begin
             TopStack := TopStack - 1;
@@ -656 +679 @@
         end;
         fnWrite: Write(DataStore[GetBaseDown(Level) + Address]:0, ' ');
-        fnRead: Read(DataStore[GetBaseDown(Level) + Address]);
+        fnRead: ReadLn(DataStore[GetBaseDown(Level) + Address]);
       end;
   until ProgramCounter = 0;
@@ -700 +723 @@
   SingleCharSymbols['<'] := skLess;
   SingleCharSymbols['>'] := skGreater;
-  SingleCharSymbols['['] := skLessOrEqual;
-  SingleCharSymbols[']'] := skGreaterOrEqual;
   SingleCharSymbols[';'] := skSemicolon;
   SingleCharSymbols['!'] := skWrite;
@@ -724 +745 @@
   LineLength := 0;
   LastChar := ' ';
-  kk := MaxIdentifierLength;
-end;
-
-begin
+end;
+
+begin
+  if ParamCount > 0 then begin
+    WriteLn(ParamStr(1));
+    Assign(SourceFile, ParamStr(1));
+    Reset(SourceFile);
+  end else SourceFile := Input;
   Init;
   ParseProgram;
+  Close(SourceFile);
   if ErrorCount = 0 then Interpret
     else Write(ErrorCount, ' errors in pl/0 program');