https://github.com/jeremyko/expression-tree-with-user-functions

c++ expression tree library
https://github.com/jeremyko/expression-tree-with-user-functions

expression-tree

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c++ expression tree library

• Host: GitHub
• URL: https://github.com/jeremyko/expression-tree-with-user-functions
• Owner: jeremyko
• License: mit
• Created: 2014-03-13T09:55:24.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2018-11-30T05:48:27.000Z (almost 6 years ago)
• Last Synced: 2024-10-12T04:05:59.607Z (about 1 month ago)
• Topics: expression-tree
• Language: C++
• Size: 556 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# c++ expression tree library

http://jeremyko.blogspot.kr/2014/03/c-expression-tree.html

# Usage 

## compile

```

mkdir build

cd build

cmake ..

make 

```

## general arithmetic

```cpp

ExpressionTree expTree;

expression_result* pExpressionRslt;

bool bRslt = false;

bRslt = expTree.SetInfixExpression("1 * -2 ");

EXPECT_TRUE(bRslt);

if (bRslt)

{

   bRslt = expTree.EvaluateExpression();

   EXPECT_TRUE(bRslt);

   pExpressionRslt = expTree.GetResult();

   cout << "expTree.EvaluateExpression returns :" 

        << pExpressionRslt->nResultLong << "\n";

   EXPECT_EQ(-2, pExpressionRslt->nResultLong);

}

```

## custom user functions

```cpp

//see user_functions.h, user_functions.cpp

//-----------------------------------------------------

bRslt = expTree.SetInfixExpression("SumInt4(SumInt4(1,1+1,1+1,2), 1+1, 1+1, 1+1)");

EXPECT_TRUE(bRslt);

bRslt = expTree.EvaluateExpression();

EXPECT_TRUE(bRslt);

pExpressionRslt = expTree.GetResult();

cout << "expTree.EvaluateExpression returns :" 

     << pExpressionRslt->nResultLong << "\n";

EXPECT_EQ(13, pExpressionRslt->nResultLong);

   

//-----------------------------------------------------

bRslt = expTree.SetInfixExpression("GetBool('1'='1')");

EXPECT_TRUE(bRslt);

bRslt = expTree.EvaluateExpression();

EXPECT_TRUE(bRslt);

   

//-----------------------------------------------------

bRslt = expTree.SetInfixExpression("StrCat('ab','cd')=StrCat('a','b')+StrCat('c','d') ");

EXPECT_TRUE(bRslt);

bRslt = expTree.EvaluateExpression();

EXPECT_TRUE(bRslt);

   

//-----------------------------------------------------

bRslt = expTree.SetInfixExpression("StrCat3('1','2',StrCat3('a','b',StrCat3('X','Y','Z')) )");

EXPECT_TRUE(bRslt);

bRslt = expTree.EvaluateExpression();

EXPECT_TRUE(bRslt);

EXPECT_EQ(4, expTree.GetDepth());

pExpressionRslt = expTree.GetResult();

cout << "expTree.EvaluateExpression returns :" << pExpressionRslt->strResult << "\n";

EXPECT_STREQ("12abXYZ", pExpressionRslt->strResult);

```

## using placeholder

```cpp

// placeholder identifier is :$ph1, :$ph2, .... :$ph50 (max)

bRslt = expTree.SetInfixExpression ( ":$ph1+:$ph2" );

EXPECT_TRUE ( bRslt );

if ( bRslt )

{

    expTree.SetNumberLongValueOfPlaceHolder ( 1, 1 );

    expTree.SetNumberLongValueOfPlaceHolder ( 2, 2 );

    bRslt = expTree.EvaluateExpression ( );

    EXPECT_TRUE ( bRslt );

    pExpressionRslt = expTree.GetResult ( );

    cout << "expTree.EvaluateExpression returns :" << pExpressionRslt->nResultLong << "\n";

    EXPECT_EQ ( 3, pExpressionRslt->nResultLong );

        

    //-----------------------------------------------------

    //there's no rebuild tree

    expTree.SetNumberFloatValueOfPlaceHolder ( 1, 2.0f );

    expTree.SetNumberFloatValueOfPlaceHolder ( 2, 3.0f );

    bRslt = expTree.EvaluateExpression ( );

    EXPECT_TRUE ( bRslt );

    pExpressionRslt = expTree.GetResult ( );

    cout << "expTree.EvaluateExpression returns :" << pExpressionRslt->nResultFloat << "\n";

    EXPECT_FLOAT_EQ ( 5.0f, pExpressionRslt->nResultFloat );

    //-----------------------------------------------------

    expTree.SetStringValueOfPlaceHolder ( 1, "A" );

    expTree.SetStringValueOfPlaceHolder ( 2, "B" );

    bRslt = expTree.EvaluateExpression ( );

    EXPECT_TRUE ( bRslt );

    pExpressionRslt = expTree.GetResult ( );

    cout << "expTree.EvaluateExpression returns :" << pExpressionRslt->strResult << "\n";

    EXPECT_STREQ ( "AB", pExpressionRslt->strResult );

}

```