Changeset 147 for branches/easy compiler/UCompiler.pas

Timestamp:

Jan 17, 2018, 3:34:13 PM (7 years ago)

Author:

chronos

Message:

• Added: Support for Repeat blocks and Break command.

File:

• branches/easy compiler/UCompiler.pas (modified) (3 diffs)

branches/easy compiler/UCompiler.pas

@@ -44 +44 @@
     procedure Parse(Code: TSourceCode);
     function ParseBeginEnd(SourceCode: TSourceCode; out BeginEnd: TCommandBeginEnd): Boolean;
+    function ParseBreak(SourceCode: TSourceCode; out CommandBreak: TCommandBreak
+      ): Boolean;
+    function ParseCommand(SourceCode: TSourceCode; out Command: TSourceCommand
+      ): Boolean;
     function ParseFunctionCall(SourceCode: TSourceCode; out FunctionCall: TCommandFunctionCall): Boolean;
     function ParseIfZero(SourceCode: TSourceCode; out IfZero: TCommandIfZero): Boolean;
     function ParseReference(SourceCode: TSourceCode): TSourceReference;
     function ParseReferenceVariable(SourceCode: TSourceCode): TSourceReference;
+    function ParseRepeat(SourceCode: TSourceCode; out
+      CommandRepeat: TCommandRepeat): Boolean;
     function ParseVar(SourceCode: TSourceCode): Boolean;
   public
@@ -306 +312 @@
   if Keyword = 'ifzero' then begin
     IfZero := TCommandIfZero.Create;
-    IfZero.Variable := TSourceReferenceVariable(ParseReferenceVariable(SourceCode)).Variable;
-    Result := True;
-  end;
-  if not Result then Tokenizer.TokenIndex := TokenIndex;
-end;
-
-function TCompiler.ParseBeginEnd(SourceCode: TSourceCode; out BeginEnd: TCommandBeginEnd): Boolean;
-var
-  Token: TSourceToken;
+    IfZero.Variable := TSourceReferenceVariable(ParseReferenceVariable(SourceCode));
+    Result := True;
+  end;
+  if not Result then Tokenizer.TokenIndex := TokenIndex;
+end;
+
+function TCompiler.ParseBreak(SourceCode: TSourceCode; out CommandBreak: TCommandBreak): Boolean;
+var
+  Token: TSourceToken;
+  TokenIndex: Integer;
   Keyword: string;
-  TokenIndex: Integer;
+begin
+  Result := False;
+  TokenIndex := Tokenizer.TokenIndex;
+  Token := Tokenizer.GetNext;
+  Keyword := LowerCase(Token.Text);
+  if Keyword = 'break' then begin
+    CommandBreak := TCommandBreak.Create;
+    Result := True;
+  end;
+  if not Result then Tokenizer.TokenIndex := TokenIndex;
+end;
+
+function TCompiler.ParseRepeat(SourceCode: TSourceCode; out CommandRepeat: TCommandRepeat): Boolean;
+var
+  Token: TSourceToken;
+  TokenIndex: Integer;
+  Keyword: string;
+  Command: TSourceCommand;
+begin
+  Result := False;
+  TokenIndex := Tokenizer.TokenIndex;
+  Token := Tokenizer.GetNext;
+  Keyword := LowerCase(Token.Text);
+  if Keyword = 'repeat' then begin
+    CommandRepeat := TCommandRepeat.Create;
+    if ParseCommand(SourceCode, Command) then begin
+      CommandRepeat := TCommandRepeat.Create;
+      CommandRepeat.Command := Command;
+      Command.Parent := CommandRepeat;
+    end else
+    raise Exception.Create('Unexpected token');
+    Result := True;
+  end;
+  if not Result then Tokenizer.TokenIndex := TokenIndex;
+end;
+
+function TCompiler.ParseCommand(SourceCode: TSourceCode; out Command: TSourceCommand): Boolean;
+var
   CommandBeginEnd: TCommandBeginEnd;
   CommandIfZero: TCommandIfZero;
   CommandFunctionCall: TCommandFunctionCall;
+  CommandBreak: TCommandBreak;
+  CommandRepeat: TCommandRepeat;
+begin
+  Command := nil;
+  Result := True;
+  if ParseVar(SourceCode) then else
+  if ParseBeginEnd(SourceCode, CommandBeginEnd) then begin
+    Command := CommandBeginEnd;
+  end else
+  if ParseIfZero(SourceCode, CommandIfZero) then begin
+    Command := CommandIfZero;
+  end else
+  if ParseBreak(SourceCode, CommandBreak) then begin
+    Command := CommandBreak;
+  end else
+  if ParseRepeat(SourceCode, CommandRepeat) then begin
+    Command := CommandRepeat;
+  end else
+  if ParseFunctionCall(SourceCode, CommandFunctionCall) then begin
+    Command := CommandFunctionCall;
+  end else Result := False;
+end;
+
+function TCompiler.ParseBeginEnd(SourceCode: TSourceCode; out BeginEnd: TCommandBeginEnd): Boolean;
+var
+  Token: TSourceToken;
+  Keyword: string;
+  TokenIndex: Integer;
+  Command: TSourceCommand;
 begin
   Result := False;
@@ -329 +402 @@
     BeginEnd.SourceCode := SourceCode;
     while True do begin
-      if ParseVar(SourceCode) then
-      else if ParseBeginEnd(SourceCode, CommandBeginEnd) then
-        BeginEnd.Instructions.Add(CommandBeginEnd)
-      else if ParseIfZero(SourceCode, CommandIfZero) then
-        BeginEnd.Instructions.Add(CommandIfZero)
-      else if ParseFunctionCall(SourceCode, CommandFunctionCall) then
-        BeginEnd.Instructions.Add(CommandFunctionCall)
-      else if Tokenizer.CheckNext('end', stIdentifier) then begin
+      if ParseCommand(SourceCode, Command) then begin
+        if Assigned(Command) then begin
+          BeginEnd.Commands.Add(Command);
+          Command.Parent := BeginEnd;
+        end;
+      end else
+      if Tokenizer.CheckNext('end', stIdentifier) then begin
         Break;
-      end
-      else raise Exception.Create('Unknown token: ' + Keyword);
+      end else begin
+        Token := Tokenizer.GetNext;
+        Keyword := LowerCase(Token.Text);
+        raise Exception.Create('Unknown token: ' + Keyword);
+      end;
     end;
     Token := Tokenizer.GetNext;