andrew-pa / textexcel

Yay APCS Yay

TextExcel

A wonderful APCS project in Java. Basically ed for a spreadsheet

Grand Scheme

Feel free to do PRs against this document if you feel something should be different

Remember, avoid stupid getter/setters, instead be clever!

Spreadsheet

Spreadsheet contains a matrix of Values that represent it's cells
Can obtain the Value at a index with valueAt

Value hierarchy

Value: base class, all values can be refine()'d in the context of some Spreadsheet, which by default will simpily return the value itself. In addition all Values should have a useful toString method
Number: a decimal value, represented by a double
StringValue: a string value
CellReference: a value that holds a cell's row and column, and when it is refine()'d it returns the value in that cell
DeferredExpression: a value that, when refine()'d, returns the evaluation of it's child expression
ErrorValue: a value that represents a error resulting from a evaluation/refinement

Expression hierarchy

Expression: base class, all expressions can be evaluate()'d in the context of some Spreadsheet
ValueExpression: a expression that represents a basic value (number, string, cellref or deferred expr)
AddExpression: a expression that evaluates to the addition of the evaluation of its two arguments
SubExpression: same as AddExpression with subtraction
Term: another base class
MulTerm: a expression that evaluates to the multiplication of the evalution of its two arguments
DivTerm: same as MulTerm with division
AssignmentExpression: a expression that assigns the value on the left of a = to the value on the right

Parser

Parser class will have a public method that takes a String and returns a Expression named parse

Main

Main class will run the basic command line, which will read a line of input, see if it is a special command (print or quit), then invoke either the special command or parse the line and evaluate the expression, printing the resulting value

textexcel's Issues

Error Handling

Yay! Extra credit for this! Still really broken there's a lot of ways to crash this so far

• ExtraCreditB – 5 pts for built-in help menu (type “help” displays all commands and how to use them)

I can probably do this but the decision is should we make this a function like sum or a check like quit. Either way it would be nice to eventually pull out a detailed list of what our program can actually do.