panthema / 2007 / stx-exparser / online

Formerly Online STX Expression Parser

This is a formerly online demonstration page of the STX Expression Parser framework. Due to changes to the website in 2012, the online demo has been taked offline. However, some static results have been retained for your information.

The input strings given below were parsed and evaluated by the library. Upon successful processing the evaluation result's type and value are displayed together with the expression's parse tree.

The results from the following examples are availabled below:

The following variables are defined in the demo and used in the expressions:

a 42
c 299792458
e 2.718281828459045
pi 3.141592653589793
golden 1.618033988749895
field1 12345678
field2 87654321
got "no"

Example 1: 6 + 3 * 12

Evaluated String

6 + 3 * 12

ParseTree Result as String

42

Evaluation Result (using the Variables Table)

42
(type: integer)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- 6 + 3 * 12 -->
<parsetree version="1.0">
    <parsenode rule="add_expr">
        <value>+</value>
        <parsenode rule="integer_const">
            <value>6</value>
        </parsenode>
        <parsenode rule="mul_expr">
            <value>*</value>
            <parsenode rule="integer_const">
                <value>3</value>
            </parsenode>
            <parsenode rule="integer_const">
                <value>12</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 2: (5 + 3) * 5.25

Evaluated String

(5 + 3) * 5.25

ParseTree Result as String

42

Evaluation Result (using the Variables Table)

42
(type: double)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- (5 + 3) * 5.25 -->
<parsetree version="1.0">
    <parsenode rule="mul_expr">
        <value>*</value>
        <parsenode rule="add_expr">
            <value>+</value>
            <parsenode rule="integer_const">
                <value>5</value>
            </parsenode>
            <parsenode rule="integer_const">
                <value>3</value>
            </parsenode>
        </parsenode>
        <parsenode rule="double_const">
            <value>5.25</value>
        </parsenode>
    </parsenode>
</parsetree>

Example 3: (int)(30 * 1.4)

Evaluated String

(int)(30 * 1.4)

ParseTree Result as String

42

Evaluation Result (using the Variables Table)

42
(type: integer)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- (int)(30 * 1.4) -->
<parsetree version="1.0">
    <parsenode rule="cast_spec">
        <value>int</value>
        <parsenode rule="mul_expr">
            <value>*</value>
            <parsenode rule="integer_const">
                <value>30</value>
            </parsenode>
            <parsenode rule="double_const">
                <value>1.4</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 4: (5 + 1 + 1 + 1) * (4.25 + 0.4 * 2.5 / (3.1 - 0.525 * 4))

Evaluated String

(5 + 1 + 1 + 1) * (4.25 + 0.4 * 2.5 / (3.1 - 0.525 * 4))

ParseTree Result as String

42

Evaluation Result (using the Variables Table)

42
(type: double)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- (5 + 1 + 1 + 1) * (4.25 + 0.4 * 2.5 / (3.1 - 0.525 * 4)) -->
<parsetree version="1.0">
    <parsenode rule="mul_expr">
        <value>*</value>
        <parsenode rule="add_expr">
            <value>+</value>
            <parsenode rule="add_expr">
                <value is_root="1">+</value>
                <parsenode rule="add_expr">
                    <value is_root="1">+</value>
                    <parsenode rule="integer_const">
                        <value>5</value>
                    </parsenode>
                    <parsenode rule="integer_const">
                        <value>1</value>
                    </parsenode>
                </parsenode>
                <parsenode rule="integer_const">
                    <value>1</value>
                </parsenode>
            </parsenode>
            <parsenode rule="integer_const">
                <value>1</value>
            </parsenode>
        </parsenode>
        <parsenode rule="add_expr">
            <value>+</value>
            <parsenode rule="double_const">
                <value>4.25</value>
            </parsenode>
            <parsenode rule="mul_expr">
                <value>/</value>
                <parsenode rule="mul_expr">
                    <value is_root="1">*</value>
                    <parsenode rule="double_const">
                        <value>0.4</value>
                    </parsenode>
                    <parsenode rule="double_const">
                        <value>2.5</value>
                    </parsenode>
                </parsenode>
                <parsenode rule="add_expr">
                    <value>-</value>
                    <parsenode rule="double_const">
                        <value>3.1</value>
                    </parsenode>
                    <parsenode rule="mul_expr">
                        <value>*</value>
                        <parsenode rule="double_const">
                            <value>0.525</value>
                        </parsenode>
                        <parsenode rule="integer_const">
                            <value>4</value>
                        </parsenode>
                    </parsenode>
                </parsenode>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 5: COS(2 * PI)

Evaluated String

COS(2 * PI)

ParseTree Result as String

COS((2 * PI))

Evaluation Result (using the Variables Table)

1
(type: double)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- COS(2 * PI) -->
<parsetree version="1.0">
    <parsenode rule="function_identifier">
        <value>COS</value>
        <parsenode rule="mul_expr">
            <value>*</value>
            <parsenode rule="integer_const">
                <value>2</value>
            </parsenode>
            <parsenode rule="varname">
                <value>PI</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 6: SQRT( COS(PI/4) * COS(PI/4) + SIN(PI/4) * SIN(PI/4) )

Evaluated String

SQRT( COS(PI/4) * COS(PI/4) + SIN(PI/4) * SIN(PI/4) )

ParseTree Result as String

SQRT(((COS((PI / 4)) * COS((PI / 4))) + (SIN((PI / 4)) * SIN((PI / 4)))))

Evaluation Result (using the Variables Table)

1
(type: double)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- SQRT( COS(PI/4) * COS(PI/4) + SIN(PI/4) * SIN(PI/4) ) -->
<parsetree version="1.0">
    <parsenode rule="function_identifier">
        <value>SQRT</value>
        <parsenode rule="add_expr">
            <value>+</value>
            <parsenode rule="mul_expr">
                <value>*</value>
                <parsenode rule="function_identifier">
                    <value>COS</value>
                    <parsenode rule="mul_expr">
                        <value>/</value>
                        <parsenode rule="varname">
                            <value>PI</value>
                        </parsenode>
                        <parsenode rule="integer_const">
                            <value>4</value>
                        </parsenode>
                    </parsenode>
                </parsenode>
                <parsenode rule="function_identifier">
                    <value>COS</value>
                    <parsenode rule="mul_expr">
                        <value>/</value>
                        <parsenode rule="varname">
                            <value>PI</value>
                        </parsenode>
                        <parsenode rule="integer_const">
                            <value>4</value>
                        </parsenode>
                    </parsenode>
                </parsenode>
            </parsenode>
            <parsenode rule="mul_expr">
                <value>*</value>
                <parsenode rule="function_identifier">
                    <value>SIN</value>
                    <parsenode rule="mul_expr">
                        <value>/</value>
                        <parsenode rule="varname">
                            <value>PI</value>
                        </parsenode>
                        <parsenode rule="integer_const">
                            <value>4</value>
                        </parsenode>
                    </parsenode>
                </parsenode>
                <parsenode rule="function_identifier">
                    <value>SIN</value>
                    <parsenode rule="mul_expr">
                        <value>/</value>
                        <parsenode rule="varname">
                            <value>PI</value>
                        </parsenode>
                        <parsenode rule="integer_const">
                            <value>4</value>
                        </parsenode>
                    </parsenode>
                </parsenode>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 7: a == 6 * 9

Evaluated String

a == 6 * 9

ParseTree Result as String

(a == 54)

Evaluation Result (using the Variables Table)

false
(type: bool)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- a == 6 * 9 -->
<parsetree version="1.0">
    <parsenode rule="comp_expr">
        <value>==</value>
        <parsenode rule="varname">
            <value>a</value>
        </parsenode>
        <parsenode rule="mul_expr">
            <value>*</value>
            <parsenode rule="integer_const">
                <value>6</value>
            </parsenode>
            <parsenode rule="integer_const">
                <value>9</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 8: a * 20000 <= c

Evaluated String

a * 20000 <= c

ParseTree Result as String

((a * 20000) <= c)

Evaluation Result (using the Variables Table)

true
(type: bool)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- a * 20000 &lt;= c -->
<parsetree version="1.0">
    <parsenode rule="comp_expr">
        <value>&lt;=</value>
        <parsenode rule="mul_expr">
            <value>*</value>
            <parsenode rule="varname">
                <value>a</value>
            </parsenode>
            <parsenode rule="integer_const">
                <value>20000</value>
            </parsenode>
        </parsenode>
        <parsenode rule="varname">
            <value>c</value>
        </parsenode>
    </parsenode>
</parsetree>

Example 9: e == EXP(1)

Evaluated String

e == EXP(1)

ParseTree Result as String

(e == EXP(1))

Evaluation Result (using the Variables Table)

true
(type: bool)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- e == EXP(1) -->
<parsetree version="1.0">
    <parsenode rule="comp_expr">
        <value>==</value>
        <parsenode rule="varname">
            <value>e</value>
        </parsenode>
        <parsenode rule="function_identifier">
            <value>EXP</value>
            <parsenode rule="integer_const">
                <value>1</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 10: golden == (1 + SQRT(5)) / 2

Evaluated String

golden == (1 + SQRT(5)) / 2

ParseTree Result as String

(golden == ((1 + SQRT(5)) / 2))

Evaluation Result (using the Variables Table)

true
(type: bool)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- golden == (1 + SQRT(5)) / 2 -->
<parsetree version="1.0">
    <parsenode rule="comp_expr">
        <value>==</value>
        <parsenode rule="varname">
            <value>golden</value>
        </parsenode>
        <parsenode rule="mul_expr">
            <value>/</value>
            <parsenode rule="add_expr">
                <value>+</value>
                <parsenode rule="integer_const">
                    <value>1</value>
                </parsenode>
                <parsenode rule="function_identifier">
                    <value>SQRT</value>
                    <parsenode rule="integer_const">
                        <value>5</value>
                    </parsenode>
                </parsenode>
            </parsenode>
            <parsenode rule="integer_const">
                <value>2</value>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 11: (a - 28) * (int)(e + 0.4 * 2.5 / (PI() - EXP(-0.644) * 4))

Evaluated String

(a - 28) * (int)(e + 0.4 * 2.5 / (PI() - EXP(-0.644) * 4))

ParseTree Result as String

((a - 28) * ((integer)(e + (1 / (PI() - (EXP(-0.64400000000000002) * 4))))))

Evaluation Result (using the Variables Table)

42
(type: integer)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- (a - 28) * (int)(e + 0.4 * 2.5 / (PI() - EXP(-0.644) * 4)) -->
<parsetree version="1.0">
    <parsenode rule="mul_expr">
        <value>*</value>
        <parsenode rule="add_expr">
            <value>-</value>
            <parsenode rule="varname">
                <value>a</value>
            </parsenode>
            <parsenode rule="integer_const">
                <value>28</value>
            </parsenode>
        </parsenode>
        <parsenode rule="cast_spec">
            <value>int</value>
            <parsenode rule="add_expr">
                <value>+</value>
                <parsenode rule="varname">
                    <value>e</value>
                </parsenode>
                <parsenode rule="mul_expr">
                    <value>/</value>
                    <parsenode rule="mul_expr">
                        <value is_root="1">*</value>
                        <parsenode rule="double_const">
                            <value>0.4</value>
                        </parsenode>
                        <parsenode rule="double_const">
                            <value>2.5</value>
                        </parsenode>
                    </parsenode>
                    <parsenode rule="add_expr">
                        <value>-</value>
                        <parsenode rule="function_identifier">
                            <value>PI</value>
                        </parsenode>
                        <parsenode rule="mul_expr">
                            <value>*</value>
                            <parsenode rule="function_identifier">
                                <value>EXP</value>
                                <parsenode rule="unary_expr">
                                    <value>-</value>
                                    <parsenode rule="double_const">
                                        <value>0.644</value>
                                    </parsenode>
                                </parsenode>
                            </parsenode>
                            <parsenode rule="integer_const">
                                <value>4</value>
                            </parsenode>
                        </parsenode>
                    </parsenode>
                </parsenode>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>

Example 12: a >= 5 OR (42 <= field2 AND field2 <= 48) || NOT(got == "yes")

Evaluated String

a >= 5 OR (42 <= field2 AND field2 <= 48) || NOT(got == "yes")

ParseTree Result as String

(((a >= 5) || ((42 <= field2) && (field2 <= 48))) || (! (got == "yes")))

Evaluation Result (using the Variables Table)

true
(type: bool)

XML Node Tree

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE parsetree SYSTEM "parsetree.dtd">
<!-- a &gt;= 5 OR (42 &lt;= field2 AND field2 &lt;= 48) || NOT(got == "yes") -->
<parsetree version="1.0">
    <parsenode rule="or_expr">
        <value>||</value>
        <parsenode rule="or_expr">
            <value is_root="1">OR</value>
            <parsenode rule="comp_expr">
                <value>&gt;=</value>
                <parsenode rule="varname">
                    <value>a</value>
                </parsenode>
                <parsenode rule="integer_const">
                    <value>5</value>
                </parsenode>
            </parsenode>
            <parsenode rule="and_expr">
                <value>AND</value>
                <parsenode rule="comp_expr">
                    <value>&lt;=</value>
                    <parsenode rule="integer_const">
                        <value>42</value>
                    </parsenode>
                    <parsenode rule="varname">
                        <value>field2</value>
                    </parsenode>
                </parsenode>
                <parsenode rule="comp_expr">
                    <value>&lt;=</value>
                    <parsenode rule="varname">
                        <value>field2</value>
                    </parsenode>
                    <parsenode rule="integer_const">
                        <value>48</value>
                    </parsenode>
                </parsenode>
            </parsenode>
        </parsenode>
        <parsenode rule="unary_expr">
            <value>NOT</value>
            <parsenode rule="comp_expr">
                <value>==</value>
                <parsenode rule="varname">
                    <value>got</value>
                </parsenode>
                <parsenode rule="string_const">
                    <value>"yes"</value>
                </parsenode>
            </parsenode>
        </parsenode>
    </parsenode>
</parsetree>
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