Changeset 141 for branches/easy compiler/UCompiler.pas

Timestamp:

Jan 16, 2018, 2:44:19 PM (7 years ago)

Author:

chronos

Message:

• Added: Support for multiple value types. String and Integer are supported for the start.
• Added: "var" keyword for compile time definition of variable and its type.
• Added: Increment function for integer values.

File:

• branches/easy compiler/UCompiler.pas (modified) (10 diffs)

branches/easy compiler/UCompiler.pas

@@ -9 +9 @@
 
 type
-  TSourceTokenKind = (stNone, stString, stIdentifier, stEof);
+  TSourceTokenKind = (stNone, stString, stIdentifier, stEof, stInteger);
   TSourceToken = record
     Text: string;
@@ -102 +102 @@
 procedure TTokenizer.Tokenize(Text: string; Tokens: TSourceTokens);
 type
-  TTokenizerState = (tsNone, tsIdentifier, tsString);
+  TTokenizerState = (tsNone, tsIdentifier, tsString, tsInteger);
 var
   State: TTokenizerState;
@@ -114 +114 @@
   while I < Length(Text) do begin
     if State = tsNone then begin
+      if IsDigit(Text[I]) then begin
+        State := tsInteger;
+        Token := Text[I];
+      end else
       if IsAlpha(Text[I]) then begin
         State := tsIdentifier;
@@ -133 +137 @@
       if IsWhiteSpace(Text[I]) then begin
         Tokens.AddToken(stIdentifier, Token);
+        State := tsNone;
+        Dec(I);
+      end else
+      raise Exception.Create('Unexpected character');
+    end else
+    if State = tsInteger then begin
+      if IsDigit(Text[I]) then begin
+        Token := Token + Text[I];
+      end else
+      if IsWhiteSpace(Text[I]) then begin
+        Tokens.AddToken(stInteger, Token);
         State := tsNone;
         Dec(I);
@@ -156 +171 @@
 var
   Token: TSourceToken;
+  Token2: TSourceToken;
   Keyword: string;
   Instruction: TSourceInstruction;
@@ -161 +177 @@
   Funct: TSourceFunction;
   Param: TSourceFunctionParameter;
+  Variable: TSourceVariable;
+  ValueType: TSourceType;
 
 function ParseReference: TSourceReference;
@@ -168 +186 @@
     NewReference := TSourceReferenceConstant.Create;
     TSourceReferenceConstant(NewReference).Constant :=
-      Code.Constants.AddNew(Token.Text);
+      Code.Constants.AddNewString(Token.Text);
   end else
   if Token.Kind = stIdentifier then begin
@@ -176 +194 @@
     if TSourceReferenceVariable(NewReference).Variable = nil then
       raise Exception.Create('Variable not found: ' + Token.Text);
-  end else raise Exception.Create('Unexpected parameter');
+  end else
+  if Token.Kind = stInteger then begin
+    NewReference := TSourceReferenceConstant.Create;
+    TSourceReferenceConstant(NewReference).Constant :=
+      Code.Constants.AddNewInteger(StrToInt(Token.Text));
+  end else
+  raise Exception.Create('Unexpected parameter');
   Result := NewReference;
 end;
@@ -187 +211 @@
     TSourceReferenceVariable(NewReference).Variable :=
       Code.Variables.Search(Token.Text);
-    if TSourceReferenceVariable(NewReference).Variable = nil then begin
-      if Initialize then
-        TSourceReferenceVariable(NewReference).Variable := Code.Variables.AddNew(Token.Text)
-        else raise Exception.Create('Variable not found: ' + Token.Text);
-    end;
+    if TSourceReferenceVariable(NewReference).Variable = nil then
+      raise Exception.Create('Variable not found: ' + Token.Text);
 
   end else raise Exception.Create('Unexpected parameter');
@@ -203 +224 @@
     if Token.Kind = stIdentifier then begin
       Keyword := LowerCase(Token.Text);
-      Funct := Code.Functions.Search(Keyword);
-      if Assigned(Funct) then begin
-        Instruction := TSourceInstructionFunction.Create;
-        TSourceInstructionFunction(Instruction).Name := Keyword;
-        for Param in Funct.Parameters do
-        if Param.Kind = pkString then begin
-          TSourceInstructionFunction(Instruction).AddParameter(ParseReference)
-        end else
-        if Param.Kind = pkVariable then begin
-          TSourceInstructionFunction(Instruction).AddParameter(ParseReferenceVariable(True));
-        end else
-        raise Exception.Create('Unsupported parameter type.');
-        Code.Instructions.Add(Instruction);
-      end else raise Exception.Create('Unsupported keyword: ' + Token.Text);
+      if Keyword = 'var' then begin
+        Token := Tokenizer.GetNext;
+        Token2 := Tokenizer.GetNext;
+        if Token2.Kind <> stIdentifier then
+          raise Exception.Create('Expected type parameter');
+        Variable := Code.Variables.Search(Token.Text);
+        if not Assigned(Variable) then begin
+          ValueType := Code.Types.Search(Token2.Text);
+          if not Assigned(ValueType) then
+            raise Exception.Create('Unsupported type: ' + Token2.Text);
+          Variable := Code.Variables.AddNew(Token.Text,
+            ValueType);
+        end else raise Exception.Create('Variable redefined');
+      end else begin
+        Funct := Code.Functions.Search(Keyword);
+        if Assigned(Funct) then begin
+          Instruction := TSourceInstructionFunction.Create;
+          TSourceInstructionFunction(Instruction).Name := Keyword;
+          for Param in Funct.Parameters do
+          if Param.Kind = pkString then begin
+            TSourceInstructionFunction(Instruction).AddParameter(ParseReference)
+          end else
+          if Param.Kind = pkVariable then begin
+            TSourceInstructionFunction(Instruction).AddParameter(ParseReferenceVariable(True));
+          end else
+          raise Exception.Create('Unsupported parameter type.');
+          Code.Instructions.Add(Instruction);
+        end else raise Exception.Create('Unsupported keyword: ' + Token.Text);
+      end;
     end else raise Exception.Create('Unsupported token kind.');
   end;