MathML to/from Plain Text Converter

• Download demo
• Download MathML_ToFrom_String_NET.zip - 6.1 MB
• Download MathML_ToFrom_String_javascript.zip - 5.8 KB
• Download MathML_ToFrom_String_Core6.0.zip - 452.3 KB

Introduction

There seems to be few resources converting MathML code into plain text. A good reason is there is no consensus in how to format some math expressions. But for many expressions involving (+,-,/,*,^,=) operators, here is one possible converter.

The Classes Engaged

• Class MathToString prepares the string with the MathML code so that class ParseML can perform the detailed parsing.

Preparation

First, the spaces are replaced by empty strings and some special characters are replaced too. Also, some tags not involved in the math expression, like style tags, are removed. Then the code goes over from the most insider <mfrac>...</mfrac>, <msup>...</msup>, <mrow>...</mrow>, <msqrt>...</msqrt> tags to the most outer, being parsed and replaced, enclosing them in between special characters so that later they can be recovered by ParseML class.

Using the Code

To convert, just call the shared method MathToString.convertToString():

Dim converted as String = MathMLToString.convertToString(MathMLcodeToConvert)

To convert text to MathML, call convertStringToMathML().

Basic Principles

The parsing method is a recursive-descent parsing: Parsing Expressions by Recursive Descent.

Evaluation method E calls T for any addition or substraction, but T calls first F for any multiplication or substraction, and F calls first P for any power possible power operation. P calls first v to get next token. If there is a "(" token, v calls recursively to T.

E --> T {( "+" | "-" ) T}
T --> F {( "*" | "/" ) F}
F --> P ["^" F]
P --> v | "(" E ")" | "-" T

History

• 12^th May, 2022: Initial version