Hi Kohei, On Wed, Feb 23, 2005 at 10:42:14 -0500, Kohei Yoshida wrote:
> You're right on! This helps tremendously. :-) This mechanism is > still a bit complicated, but I will try to understand it slowly but > surely. I'd do it differently in a new implementation, but I don't think it would be less complicated ;-) > Ultimately, I'd like to see how a given string of formula, say, > "=B5*2+(C2/D10)" gets transformed into an array of ScToken's for later > processing of that formula. If you want to dive into it: compile sc/source/core/tool/compiler.cxx with debug and set breakpoints at ScCompiler::CompileString() and ScCompiler::CompileTokenArray(). If you enter a formula cell, first CompileString() is called that transforms the string into tokens, then CompileTokenArray() is called that creates the RPN array in its final form. > My goal is to create a similar > functionality in my UNO component so that I can transform an arbitrary > formula string into a standard form of linear or polynomial equation. > This way I can apply all kinds of mathematical algorithms to that > equation to do some fun stuff. ;-) > > Or, could this functionality (i.e. tokenization of a formula string) > be somehow exported via the API? Is that technically achievable? > What would be the difficulty level? It can't be exported via API, as the compiler and the resulting token array would need access to internal document structures. I suggest you take a look at Boost's Spirit parser framework, see http://boost.org/libs/spirit/index.html and/or search the web for recursive-descent parser, with or without RPN. There are many sample sources. For more complex grammars, tools like lex/flex and yacc/bison may be helpful. Eike -- OOo/SO Calc core developer. Number formatter bedevilled I18N transpositionizer. GnuPG key 0x293C05FD: 997A 4C60 CE41 0149 0DB3 9E96 2F1A D073 293C 05FD --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
