abacus

About

Table data editor with the support of formulas.

Highlights

• graphical UI
• cells edition
• formulas with custom language
• endless scroll
• basic cell and text formatting

Formula language

Supported expressions

The language supports following expressions:

• number value, ie. 1, -12.34
• text value, ie. abc
• logic value: true or false
• formulas, ie. =add(1, 2)

Formulas syntax

Formulas start with = followed by formula name and arguments. Simple formula call looks as follows:

=add(1, 2) # 3

To use text value as argument wrap in with '':

=length('abc ') # 4

Other cell can be referenced with its address:

=add(1, B5) # 1 + value of B5

Formulas can take other formulas as arguments:

=abs(add(-10, length('abc'))) # 7

Available formulas

Math

Basic:

• abs(number) -> number
• add(vararg number) -> number
• ceil(number) -> number
• div(number, number) -> number
• divide(vararg number) -> number
• floor(number) -> number
• mod(number, number) -> number
• multiply(vararg number) -> number
• subtract(vararg number) -> number

Stats:

• max(vararg number) -> number
• mean(vararg number) -> number
• min(vararg number) -> number
• std(vararg number) -> number

Text

• length(text) -> number
• lower(text) -> text
• sub(text, number, number) -> text
• upper(text) -> text

Logic

• compare(vararg any) -> logic
• if(logic, any, any) -> any

Running it

Note that the app was tested only on Windows.

Requirements:

• Java 15
• physical display

Steps:

1. Checkout the code
2. Type ./gradlew run

Possible enhancements

Features:

• cell range reference
• working side menu (ie. saving, undo/redo, search)
• syntax highlighting
• event based user behaviour metrics

Technical:

• split app into three modules
• integration tests