Changeset 97 for branches/interpreter/Parser3.pas

Timestamp:

Feb 2, 2017, 11:35:09 PM (8 years ago)

Author:

chronos

Message:

• Modified: Improved parsin and prepared analyzed source execution.

File:

• branches/interpreter/Parser3.pas (modified) (14 diffs)

branches/interpreter/Parser3.pas

@@ -24 +24 @@
 
 function ParseIfThen(IfThenElse: PIfThenElse): Boolean; forward;
-function ParseExecution: Boolean; forward;
+function ParseWhileDo(WhileDo: PWhileDo): Boolean; forward;
+function ParseExecution(Execution: PExecution): Boolean; forward;
+function ParseBeginEnd(BeginEnd: PBeginEnd): Boolean; forward;
 
 
@@ -35 +37 @@
 begin
   Result := (C = ';') or (C = '(') or (C = ')') or (C = ':') or (C = '=') or
-    (C = '+') or (C = '-');
+    (C = '+') or (C = '-') or (C = ';') or (C = '.');
 end;
 
@@ -142 +144 @@
 function IsOperator(Text: string): Boolean;
 begin
-  Result := (Text = '=') or (Text = '<>') or (Text = '>') or (Text = '<') or
+  Result := (Text = '+') or (Text = '-') or
+    (Text = '=') or (Text = '<>') or (Text = '>') or (Text = '<') or
     (Text = '<=') or (Text = '>=');
 end;
@@ -169 +172 @@
   Variable: PVariable;
   SubExpression: TExpression;
+  Execution: TExecution;
 begin
   Result := True;
+  if CheckNext('not') then begin
+    Expect('not');
+  end;
   if CheckNext('(') then begin
     Expect('(');
@@ -177 +184 @@
   end else
   if ParseVariable(Variable) then begin
+    OldPos := InputTextPos;
     Next := ReadNext;
     if IsOperator(Next) then begin
@@ -183 +191 @@
 
       //end else ShowError('Expected variable');
-    end else ShowError('Exprected operator but found ' + ReadNext);
+    end else InputTextPos := OldPos;
   end else
   if LastTokenType = ttString then begin
-
-  end else
-  if ParseExecution then begin
+    ReadNext
+  end else
+  if ParseExecution(@Execution) then begin
   end else
   ShowError('Expected variable but found ' + ReadNext);
@@ -194 +202 @@
   OldPos := InputTextPos;
   Next := ReadNext;
-  if IsLogicOperator(Next) then begin
+  if IsLogicOperator(Next) or IsOperator(Next) then begin
     R := ParseExpression(@SubExpression);
   end else InputTextPos := OldPos;
@@ -214 +222 @@
 end;
 
-function ParseExecution: Boolean;
+function ParseExecution(Execution: PExecution): Boolean;
 var
   OldPos: Integer;
@@ -220 +228 @@
   Func: PFunction;
   I: Integer;
+  Expression: TExpression;
 begin
   Result := True;
@@ -230 +239 @@
       I := 0;
       while I < Length(Func^.Parameters.Items) do begin
-        Next := ReadNext;
+        ParseExpression(@Expression);
         if I < (Length(Func^.Parameters.Items) - 1) then Expect(',');
         I := I + 1;
@@ -245 +254 @@
 var
   IfThenElse: TIfThenElse;
+  WhileDo: TWhileDo;
+  BeginEnd: TBeginEnd;
+  Execution: TExecution;
 begin
   Result := True;
+  if ParseBeginEnd(@BeginEnd) then begin
+  end else
   if ParseAssignment then begin
   end else
-  if ParseExecution then begin
-
+  if ParseExecution(@Execution) then begin
   end else
   if ParseIfThen(@IfThenElse) then begin
-
+  end else
+  if ParseWhileDo(@WhileDo) then begin
   end else Result := False;
 end;
@@ -269 +283 @@
       ParseCommand;
     end;
+  end else Result := False;
+end;
+
+function ParseWhileDo(WhileDo: PWhileDo): Boolean;
+begin
+  if CheckNext('while') then begin
+    Result := True;
+    Expect('while');
+    ParseExpression(@WhileDo.Condition);
+    Expect('do');
+    ParseCommand;
   end else Result := False;
 end;
@@ -364 +389 @@
     ParseParams(@Func^.Parameters);
     Expect(';');
+    if ParseVariableSection then begin
+    end;
     ParseBeginEnd(@Func^.BeginEnd);
     Expect(';');
@@ -396 +423 @@
   ProgramCode^.Variables.Add(VariableCreate('Result', TypeString));
   ProgramCode^.Variables.Add(VariableCreate('C', TypeChar));
+  ProgramCode^.Variables.Add(VariableCreate('Text', TypeString));
 
   SetLength(ProgramCode^.Functions.Items, 0);