FormulaParser

A Java library to parse Seamly2D/Valentina formulas.

A parser that can understand Valentina/Seamly2D formula, as seen, for example in the length attribute of drawing objects.

This outputs the formula as XML which represents the tree structure of the formula taking operator precedence into account, and recognising tokens as being numbers or references.

This was developed for https://seamly.cloud/ to assist with the parsing of uploaded patterns.

For instance:

formulaToXML( "a + 5 / 2" )

returns:

<?xml version="1.0" ?>
<operation type="add">
    <variable>a</variable>
    <operation type="divide">
        <integer>5</integer>
        <integer>2</integer>
  </operation>
</operation>

Output XML

Output tags are:

<operation type="TYPE"> p1, p2 
</operation>
Where TYPE in: add, multiply, divide, subtract, power, greaterThan, lessThan, greaterThanOrEqual, lessThanOrEqual, equalTo, notEqualTo.

<operation type="ternary"> if, then, else 
</operation>

<parenthesis>
</parenthesis>

<function type="FUNC">
</function>
Where FUNC is the function name. 

<variable custom="true" hash="false">
</variable>
The parameters custom and hash are binary flags indicating that the variable name starts with @ or # respectively.

<decimal>3.1415</decimal>

<integer>10</integer>