Editable Table Viewport with Formula Support

A JavaScript application that displays an editable spreadsheet-like table with viewport navigation, multiple sheet support, reactive formula computation, main menu, command line interface, context menu, cell tips, advanced selection features, and file operations.

Screenshots

Tests

Selections: Parts

Selections: Whole

Features

7x7 Viewport: Displays a fixed 7x7 grid of cells (7 rows × 7 columns)
Multiple Sheets: Supports multiple worksheets with independent data
Formula Support:
- Basic arithmetic expressions (+, -, *, /, ^)
- Spreadsheet functions: SUM, AVG, MAX, MIN, COUNT, SUMPRODUCT, VLOOKUP
- Mathematical Functions: ABS, ACOS, ANGLE, ASIN, ATN, CEIL, COS, COT, CSC, DEG, EXP, FLOOR, FP, INT, IP, LOG, LOG10, MOD, POWER, POW, RAD, RMD, RND, SEC, SGN, SIN, SQR, TAN
- Utility Functions: DATE, EPS, INF, PI, TIME
- Cell references (e.g., A1, B2, ZZ14)
- Range references (e.g., A1:C3)
- Cross-sheet references (e.g., first.A1, second.B3)
Main Menu Bar: File, Edit, Selection, Navigation, View, Help menus with keyboard shortcuts
Command Line Interface: Execute commands with history and auto-completion
File Operations: Open/Save .edt files, Export to CSV
Advanced Selection System:
- Column selection (click column headers)
- Row selection (click row headers)
- Individual cell selection (Ctrl+Click)
- Range selection (Shift+Arrow keys or Shift+Click)
- Select All (Ctrl+A)
- Clear selection (Esc)
- Per-sheet selection persistence
Context Menu: Right-click on any cell for quick actions
Cell Tips: Add, show, hide, edit, and delete sticky notes for any cell
Copy/Cut/Paste: Full clipboard support with metadata preservation
Dual Mode Display:
- Formulas Mode: Shows actual formulas (e.g., =SUM(A1:A3))
- Results Mode: Shows computed values
Reactive Computation: Formulas automatically recalculate when referenced cells change
Cell Editing: Double-click any cell to edit its content
Viewport Navigation: Move the viewport around a virtual grid:
- Move to top/bottom/left/right edges (Page Up/Down, Home/End)
- Step up/down/left/right one row/column at a time (Ctrl+Page Up/Down, Ctrl+Home/End)
- Arrow key navigation with auto-scroll
Large Virtual Grid: Supports up to 999 rows and columns up to ZZZ (18,278 columns)
Position & Selection Indicator: Shows current viewport range, active mode, and selection status

Mathematical Functions Reference

The application includes a comprehensive set of mathematical and trigonometric functions for advanced calculations.

Absolute Value and Sign Functions

Function	Syntax	Description	Example	Result
ABS	`=ABS(x)`	Returns the absolute value of x	`=ABS(-5)`	`5`
SGN	`=SGN(x)`	Returns the sign of x (-1, 0, or 1)	`=SGN(-5)`	`-1`
INT	`=INT(x)`	Returns the largest integer ≤ x (same as FLOOR)	`=INT(5.8)`	`5`
FLOOR	`=FLOOR(x)`	Returns the largest integer ≤ x	`=FLOOR(5.8)`	`5`
CEIL	`=CEIL(x)`	Returns the smallest integer ≥ x	`=CEIL(5.3)`	`6`
IP	`=IP(x)`	Returns the integer part (truncates toward zero)	`=IP(-5.75)`	`-5`
FP	`=FP(x)`	Returns the fractional part of x	`=FP(5.75)`	`0.75`

Power and Exponentiation Functions

Function	Syntax	Description	Example	Result
POWER	`=POWER(base, exponent)`	Returns base raised to the power exponent	`=POWER(2.5, 3)`	`15.625`
POW	`=POW(base, exponent)`	Alias for POWER function	`=POW(2, 3)`	`8`
^ operator	`=base ^ exponent`	Exponentiation operator	`=2.5 ^ 3`	`15.625`

Note: The POWER function (and its POW alias) support both comma (

,

) and semicolon (

) as argument separators. The caret operator (

) provides a convenient shorthand for exponentiation.

Exponentiation Rules and Edge Cases

Case	Example	Result	Explanation
Positive base	`=POWER(2.5, 3)`	`15.625`	Standard exponentiation
Exponent zero	`=POWER(2, 0)`	`1`	Any number ^ 0 = 1
Negative exponent (integer)	`=POWER(2.5, -2)`	`0.16`	1 / (2.5²)
Negative exponent (float)	`=POWER(2, -1.5)`	`0.353553`	1 / (2^1.5)
Fractional base	`=POWER(0.5, 3)`	`0.125`	0.5³
Negative base, odd exponent	`=POWER(-2, 3)`	`-8`	(-2)³
Negative base, even exponent	`=POWER(-2.5, 2)`	`6.25`	(-2.5)²
Zero base, positive exponent	`=POWER(0, 2)`	`0`	0²
Zero base, exponent zero	`=POWER(0, 0)`	`#NUM!`	Undefined
Zero base, negative integer	`=POWER(0, -1)`	`#DIV/0!`	Division by zero
Zero base, negative float	`=POWER(0, -0.5)`	`#NUM!`	1/√0 (undefined)
Negative base, fractional exponent	`=POWER(-4, 0.5)`	`#NUM!`	√(-4) (complex)

Trigonometric Functions (Radians)

Function	Syntax	Description	Example	Result
SIN	`=SIN(x)`	Returns the sine of x (x in radians)	`=SIN(PI/2)`	`1`
COS	`=COS(x)`	Returns the cosine of x (x in radians)	`=COS(0)`	`1`
TAN	`=TAN(x)`	Returns the tangent of x (x in radians)	`=TAN(PI/4)`	`1`
COT	`=COT(x)`	Returns the cotangent of x	`=COT(PI/4)`	`1`
SEC	`=SEC(x)`	Returns the secant of x (1/cos(x))	`=SEC(0)`	`1`
CSC	`=CSC(x)`	Returns the cosecant of x (1/sin(x))	`=CSC(PI/2)`	`1`

Inverse Trigonometric Functions

Function	Syntax	Description	Domain	Example	Result
ASIN	`=ASIN(x)`	Returns the arcsine of x (Quadrants I/IV)	[-1, 1]	`=ASIN(1)`	`π/2` (1.5708)
ACOS	`=ACOS(x)`	Returns the arccosine of x (Quadrants I/II)	[-1, 1]	`=ACOS(0)`	`π/2` (1.5708)
ATN	`=ATN(x)`	Returns the arctangent of x (Quadrants I/IV)	All reals	`=ATN(1)`	`π/4` (0.7854)
ANGLE	`=ANGLE(x, y)`	Returns the angle φ formed by point (x,y)	All reals	`=ANGLE(1,1)`	`π/4` (0.7854)

Note:

ANGLE(x, y)

is equivalent to

ATAN2(y, x)

and returns the angle in radians between the positive x-axis and the point (x, y), ranging from -π to π.

Exponential and Logarithmic Functions

Function	Syntax	Description	Domain	Example	Result
EXP	`=EXP(x)`	Returns e raised to the power x	All reals	`=EXP(1)`	`2.71828`
LOG	`=LOG(x)`	Returns the natural logarithm of x	x > 0	`=LOG(EXP(1))`	`1`
LOG10	`=LOG10(x)`	Returns the base-10 logarithm of x	x > 0	`=LOG10(100)`	`2`
SQR	`=SQR(x)`	Returns the positive square root of x	x ≥ 0	`=SQR(4)`	`2`

Angle Conversion Functions

Function	Syntax	Description	Example	Result
DEG	`=DEG(x)`	Converts radians to degrees	`=DEG(PI)`	`180`
RAD	`=RAD(x)`	Converts degrees to radians	`=RAD(90)`	`π/2` (1.5708)

Arithmetic and Modulo Functions

Function	Syntax	Description	Example	Result
MOD	`=MOD(x, y)`	Returns x modulo y (x - y * floor(x/y))	`=MOD(10,3)`	`1`
RMD	`=RMD(x, y)`	Returns the remainder of x/y (x - y * truncate(x/y))	`=RMD(10,3)`	`1`

Constants and Utility Functions

Function	Syntax	Description	Example	Result
PI	`=PI` or `=PI()`	Returns the mathematical constant π	`=PI`	`3.141592653589793`
EPS	`=EPS()`	Returns machine epsilon (smallest representable number)	`=EPS()`	`2.22e-16`
INF	`=INF()`	Returns positive infinity	`=INF()`	`Infinity`
DATE	`=DATE()`	Returns current date in dd-mm-yyyy format	`=DATE()`	`06-04-2026`
TIME	`=TIME()`	Returns seconds since midnight	`=TIME()`	`50742`
RND	`=RND()`	Returns a pseudo-random number in [0, 1)	`=RND()`	`0.423`

Function Usage Examples

Selection System

The application features a comprehensive selection system that allows you to select cells, rows, columns, and ranges with visual feedback.

Selection Methods

Method	Action	Description
Click column header	Select entire column	Click on any column letter (A, B, C, etc.)
Click row header	Select entire row	Click on any row number (1, 2, 3, etc.)
Ctrl+Click on cell	Toggle cell selection	Add or remove individual cell from selection
Shift+Click on cell	Range selection	Select range from current focus to clicked cell
Shift+Arrow keys	Extend range	Expand selection from current focus
Ctrl+A	Select all	Select all cells in the entire sheet
Esc	Clear selection	Remove all current selections

Selection Visual Feedback

Selection Type	Color	Description
Column selection	Blue background	Entire column highlighted
Row selection	Red background	Entire row highlighted
Individual cell	Green background	Selected cells highlighted
Range selection	Purple background	Rectangular range highlighted
Select All	Light green background	All visible cells highlighted
Focus cell	Green thick border	Current active cell indicator

Selection Status Display

A selection status bar at the top of the application shows:

"All Cells Selected" when entire sheet is selected
Column names when columns are selected
Row numbers when rows are selected
Range addresses (e.g., A1:C3) when ranges are selected
Cell addresses when individual cells are selected

Selection Persistence

Selections are saved per sheet (each sheet maintains its own selection state)
Selections are preserved when switching between sheets
Selections are saved to .edt files and restored on open
Focus cell position is saved and restored

Key Combination	Action
`↑` `↓` `←` `→`	Move focus (auto-scrolls viewport)
`Shift` + `↑` `↓` `←` `→`	Extend range selection
`Page Up`	Move to top edge
`Page Down`	Move to bottom edge
`Home`	Move to left edge
`End`	Move to right edge
`Ctrl+Page Up`	Step up one row
`Ctrl+Page Down`	Step down one row
`Ctrl+Home`	Step left one column
`Ctrl+End`	Step right one column

Right-click on any cell to open a context menu with the following options:

Edit Submenu

Menu Item	Keyboard Shortcut	Description
Copy	`Ctrl+C`	Copy cell content to clipboard
Cut	`Ctrl+X`	Cut cell content to clipboard and clear the cell
Paste	`Ctrl+V`	Paste clipboard content to selected cell

Tips Submenu

The Tips submenu is dynamic and changes based on the cell's tip state:

Cell State	Menu Items
No tip exists	Add Tip
Tip exists and visible	Hide Tip, Edit Tip, Delete Tip
Tip exists and hidden	Show Tip, Edit Tip, Delete Tip

Tip Operations

Operation	Description
Add Tip	Adds a yellow sticky note to the cell with custom text
Show Tip	Displays a hidden tip
Hide Tip	Hides a visible tip (preserves content)
Edit Tip	Modifies the tip text
Delete Tip	Permanently removes the tip

Tip Features:

Yellow background with light bulb icon (💡)
Rounded corners with arrow pointing to cell
Close button to dismiss
Auto-positioning (above cell by default, below if not enough space)
Persists across sheet switches and saves
Visual indicator (💡) in top-right corner of cells with tips

The application features a comprehensive main menu bar with the following menus and items:

Menu Item	Action	Keyboard Shortcut	Description
Open .edt	Open file dialog	`Ctrl+O`	Open a previously saved `.edt` spreadsheet file
Save .edt	Save current data	`Ctrl+S`	Save all sheets data to an `.edt` file
Export to CSV	Export current sheet	`Ctrl+E`	Export the current sheet to CSV format

Menu Item	Action	Description
Formulas Mode	Switch to formulas view	Display cell formulas instead of computed values
Results Mode	Switch to results view	Display computed values instead of formulas

Menu Item	Action	Keyboard Shortcut	Description
Select All	Select entire sheet	`Ctrl+A`	Select all cells in the spreadsheet
Clear Selection	Remove all selections	`Esc`	Clear all current selections

Menu Item	Action	Keyboard Shortcut	Description
Move to Top	Go to top edge	`Page Up`	Move viewport to the top of the sheet
Move to Bottom	Go to bottom edge	`Page Down`	Move viewport to the bottom of the sheet
Move to Left Edge	Go to left edge	`Home`	Move viewport to the left edge
Move to Right Edge	Go to right edge	`End`	Move viewport to the right edge
Step Up	Move up one row	`Ctrl+Page Up`	Move viewport up one row
Step Down	Move down one row	`Ctrl+Page Down`	Move viewport down one row
Step Left	Move left one column	`Ctrl+Home`	Move viewport left one column
Step Right	Move right one column	`Ctrl+End`	Move viewport right one column

Menu Item	Action	Keyboard Shortcut	Description
Refresh	Refresh the view	`F5`	Refresh the current view and recalculate all formulas

Menu Item	Action	Description
About	Show about dialog	Display application information and version
Keyboard Shortcuts	Show shortcuts dialog	Display all available keyboard shortcuts

Command Line Interface

The command line interface provides a developer-friendly way to control the spreadsheet. Press `Ctrl+`` (backtick) to focus the command input.

Available Commands

File Commands

Command	Usage	Description
`open`	`open`	Open an `.edt` file
`save`	`save [filename]`	Save spreadsheet to `.edt` file
`export`	`export [filename]`	Export current sheet to CSV

View Commands

Command	Usage	Description
`formulas`	`formulas`	Switch to Formulas Mode
`results`	`results`	Switch to Results Mode
`refresh`	`refresh`	Refresh the current view

Command	Usage	Description
`goto`	`goto <cell>`	Move viewport to specific cell (e.g., `goto A1`)
`sheet`	`sheet <sheetname>`	Switch to a different sheet

Info Commands

Command	Usage	Description
`ls`	`ls`	List all available sheets
`info`	`info`	Show current spreadsheet information
`help`	`help [command]`	Show available commands or help for specific command

System Commands

Command	Usage	Description
`clear`	`clear`	Clear the command line output
`history`	`history`	Show command history
`exit`	`exit`	Close the command line interface

Command Line Features

Command History: Use ↑ and ↓ arrow keys to navigate through command history
Output Coloring: Different message types have distinct colors:
- info - Blue
- success - Green
- error - Red
- warning - Orange
Collapsible Output: Click the header to minimize/hide command history
Keyboard Shortcut: `Ctrl+`` (backtick) to focus the command input
Clear Output: Use the ⌧ button or clear command

Keyboard Shortcuts

File Operations

Shortcut	Action
`Ctrl+O`	Open .edt file
`Ctrl+S`	Save .edt file
`Ctrl+E`	Export to CSV

Edit Operations

Shortcut	Action
`Ctrl+C`	Copy selected cell
`Ctrl+X`	Cut selected cell
`Ctrl+V`	Paste to selected cell
`Double-click`	Edit cell content

Selection Operations

Shortcut	Action
`Ctrl+A`	Select all cells
`Esc`	Clear all selections
`Shift+Click`	Range selection
`Ctrl+Click`	Toggle cell selection

Shortcut	Action
`↑` `↓` `←` `→`	Move focus (auto-scroll)
`Shift` + `↑` `↓` `←` `→`	Extend range selection
`Page Up`	Move to top edge
`Page Down`	Move to bottom edge
`Home`	Move to left edge
`End`	Move to right edge
`Ctrl+Page Up`	Step up one row
`Ctrl+Page Down`	Step down one row
`Ctrl+Home`	Step left one column
`Ctrl+End`	Step right one column

System

Shortcut	Action
`F5`	Refresh view
Ctrl+``	Toggle command line

Expressions and Spreadsheet Functions

The Editable Table Viewport supports a powerful formula engine with AST-based computation. Below is comprehensive documentation on supported expressions and functions.

Basic Arithmetic Expressions

All formulas must start with the

=

character.

Operation	Syntax	Example	Result
Addition	`=value + value`	`=10 + 20`	`30`
Subtraction	`=value - value`	`=50 - 25`	`25`
Multiplication	`=value * value`	`=5 * 6`	`30`
Division	`=value / value`	`=100 / 4`	`25`
Exponentiation	`=base ^ exponent`	`=2.5 ^ 3`	`15.625`
Combined	`=(value + value) * value`	`=(10 + 20) * 5`	`150`
Nested Parentheses	`=((a + b) * c) / d`	`=((10 + 20) * 5) / 2`	`75`

Supported Operands

Numbers: Integers and decimals (e.g., 42, 3.14, 10.5)
Cell References: Single cells (e.g., A1, B2, ZZ14)
Cross-Sheet References: Cells from other sheets (e.g., first.A1, second.B3)

Spreadsheet Functions

The following built-in functions are available for data computation:

SUM

Calculates the sum of all numeric values in a range or list of arguments.

=SUM(range)
=SUM(value1, value2, ...)

Examples:

Formula	Description	Result
`=SUM(A1:A10)`	Sum of values in range A1 through A10	Sum of 10 cells
`=SUM(A1:C3)`	Sum of values in rectangular range	Sum of 9 cells
`=SUM(A1, B2, C3)`	Sum of specific cells	A1 + B2 + C3
`=SUM(first.A2:A4)`	Cross-sheet range sum (shorthand)	Sum from another sheet

AVG

Calculates the arithmetic mean (average) of all numeric values in a range.

=AVG(range)
=AVG(value1, value2, ...)

Examples:

Formula	Description	Result
`=AVG(A1:A5)`	Average of values in range A1 through A5	Sum / Count
`=AVG(C17:E17)`	Average of cells C17, D17, E17	(C17+D17+E17)/3
`=AVG(first.C17:E17)`	Cross-sheet average (shorthand)	Average from another sheet

Note: Empty cells and non-numeric values are excluded from the calculation.

MAX

Returns the maximum (largest) numeric value in a range.

=MAX(range)
=MAX(value1, value2, ...)

Examples:

Formula	Description	Result
`=MAX(A1:A100)`	Maximum value in range A1 through A100	Highest value
`=MAX(C1:C10)`	Maximum of 10 cells	Highest of C1-C10
`=MAX(first.A1, second.B2)`	Maximum across sheets	Larger of two values

MIN

Returns the minimum (smallest) numeric value in a range.

=MIN(range)
=MIN(value1, value2, ...)

Examples:

Formula	Description	Result
`=MIN(D1:D10)`	Minimum value in range D1 through D10	Lowest value
`=MIN(A1:C3)`	Minimum of rectangular range	Lowest of 9 cells

COUNT

Counts the number of numeric values in a range.

=COUNT(range)
=COUNT(value1, value2, ...)

Examples:

Formula	Description	Result
`=COUNT(E1:E20)`	Count of numeric values in range	Number of cells with numbers
`=COUNT(A1, B2, C3)`	Count of specific cells	3 (if all numeric)

SUMPRODUCT

Multiplies corresponding components in the given arrays and returns the sum of those products.

=SUMPRODUCT(range1, range2)
=SUMPRODUCT(range1, range2, range3, ...)

Key Features:

Supports 2 or more ranges
Ranges must have the same dimensions (same number of cells)
Empty cells are treated as 0
Non-numeric values are ignored
Supports cross-sheet references
Works with single row, single column, and rectangular ranges

Examples:

Formula	Description	Calculation	Result
`=SUMPRODUCT(A1:A3, B1:B3)`	Two vertical ranges	A1×B1 + A2×B2 + A3×B3	Sum of products
`=SUMPRODUCT(A1:C1, A2:C2)`	Two horizontal ranges	A1×A2 + B1×B2 + C1×C2	Sum of products
`=SUMPRODUCT(A1:A2, B1:B2, C1:C2)`	Three ranges	(A1×B1×C1) + (A2×B2×C2)	Sum of triple products
`=SUMPRODUCT(first.A1:A3, second.B1:B3)`	Cross-sheet ranges	Multiplies values across sheets	Sum of cross-sheet products

Practical Examples:

Use Cases:

Weighted Averages: =SUMPRODUCT(weights, values) / SUM(weights)
Dot Product: Calculate vector dot product of two ranges
Conditional Sums: Combine with Boolean expressions
Cross-Sheet Analysis: Aggregate data from multiple worksheets
Multi-dimensional Calculations: Multiply three or more ranges for volume/area calculations

VLOOKUP

Looks up a value in the first column of a table and returns a value in the same row from a specified column.

=VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup])

Arguments:

Argument	Description	Required
`lookup_value`	The value to search for in the first column of the table	Yes
`table_array`	The range of cells that contains the lookup table	Yes
`col_index_num`	The column number in the table from which to return a value (1-indexed)	Yes
`range_lookup`	Optional. TRUE = approximate match (default), FALSE = exact match	No

Key Features:

Exact Match (FALSE/0): Finds exact match, returns #N/A if not found
Approximate Match (TRUE/1): Finds closest match (requires first column sorted ascending)
Cross-Sheet Support: Can reference tables from other sheets
Case-Insensitive: String matching is case-insensitive
Type Handling: Properly handles numbers, strings, and mixed types

Examples:

Formula	Description	Result
`=VLOOKUP("Product B", A1:B3, 2, FALSE)`	Exact match for Product B	Returns 200
`=VLOOKUP(85, A1:B6, 2, TRUE)`	Approximate match for grade	Returns "B"
`=VLOOKUP(A1, prices.A1:B100, 2, FALSE)`	Cross-sheet exact lookup	Returns price

Error Messages:

Error	Cause
`#ERROR: VLOOKUP requires at least 3 arguments`	Missing required arguments
`#ERROR: Invalid column index number`	Column index < 1 or not a number
`#ERROR: Invalid table range`	Table array is not a valid range
`#ERROR: Column index exceeds table width`	Column number > table columns
`#N/A`	No exact match found

POWER / POW

Raises a number to a specified power.

=POWER(base, exponent)
=POW(base, exponent)
=base ^ exponent

Arguments:

Argument	Description	Required
`base`	The base number	Yes
`exponent`	The exponent to raise the base to	Yes

Key Features:

Supports both comma (,) and semicolon (;) as argument separators
Handles positive and negative bases
Handles integer and floating-point exponents
Follows Excel behavior for edge cases

Examples:

Formula	Description	Result
`=POWER(2.5, 3)`	2.5 raised to the 3rd power	15.625
`=POW(2, 3)`	2 raised to the 3rd power (alias)	8
`=2 ^ 3`	Caret operator shorthand	8
`=POWER(2, -2)`	2 raised to the -2nd power	0.25
`=POWER(0, 5)`	Zero raised to positive power	0
`=POWER(-2, 3)`	Negative base with odd exponent	-8
`=POWER(-2.5, 2)`	Negative base with even exponent	6.25

Error Messages:

Error	Cause
`#NUM!`	0^0 (undefined) or negative base with fractional exponent
`#DIV/0!`	0 raised to a negative integer exponent

Cell References

Single Cell Reference

Reference a specific cell by its column letter and row number.

=A1        // Column A, Row 1
=B2        // Column B, Row 2
=ZZ14      // Column ZZ, Row 14

Range Reference

Reference a rectangular range of cells using the colon (

:

) separator.

=A1:C3     // From A1 to C3 (9 cells total)
=A1:A10    // Column A, rows 1 through 10
=B5:Z5     // Row 5, columns B through Z

Cross-Sheet References

Reference cells from other worksheets using the

sheetname.cell

format.

Single Cell Cross-Sheet

=first.A1           // Value from sheet "first", cell A1
=second.B3 + 100    // Value from sheet "second" plus 100

Range Cross-Sheet (Shorthand)

=SUM(first.A2:A4)           // Sum range in "first" sheet (end cell same sheet)
=AVG(first.C17:E17)         // Average range in "first" sheet (shorthand)
=SUMPRODUCT(first.A1:A5, second.B1:B5)  // SUMPRODUCT across sheets
=VLOOKUP(A1, prices.A1:B100, 2, FALSE)  // VLOOKUP across sheets

Note: Cross-sheet ranges support shorthand notation where the sheet name only needs to be specified before the start cell (e.g.,

first.A2:A4

Architecture

The application follows a clean modular MVC-like architecture with separate concerns. The codebase is organized into several directories:

Core Components (`/classes`)

Class	Description
`ASTNode`	Represents nodes in the Abstract Syntax Tree
`ASTEvaluator`	Evaluates AST nodes and handles cell references
`ComputationEngine`	Main entry point for formula computation
`DataHolder`	Stores all sheet data and provides CRUD operations
`FunctionRegistry`	Dynamically loads spreadsheet functions
`SimpleFormulaParser`	Parses formula strings directly into AST nodes
`ViewModel`	Provides computed properties for view state
`SheetView`	Renders the 7x7 viewport as an HTML table
`NavButtonsController`	Handles viewport navigation
`CellsEditablesController`	Manages cell edit events
`AppController`	Orchestrates all components
`MainMenu`	Creates and manages the main menu bar
`CommandLine`	Provides command line interface
`UITip`	Manages cell tip display
`PopupContextMenu`	Handles right-click context menu
`SelectionDataHolder`	Stores selection data per sheet
`SelectionViewDrawer`	Applies selection styles to cells
`SelectionManager`	Manages selection events and state

Actions (`/actions`)

Action	Description
`OpenAction`	Open .edt JSON files
`SaveAction`	Save spreadsheet as .edt
`ExportCSVAction`	Export current sheet to CSV
`ActionMoveToTop/Bottom/Left/Right`	Edge navigation actions
`ActionStepUp/Down/Left/Right`	Step navigation actions
`MoveFocusUp/Down/Left/RightAction`	Focus movement actions
`SelectAllCellsAction`	Select all cells action
`ActionCopy`	Copy cell content to clipboard
`ActionCut`	Cut cell content to clipboard
`ActionPaste`	Paste clipboard content to cell
`ActionAddTip`	Add a tip to a cell
`ActionShowTip`	Show a hidden tip
`ActionHideTip`	Hide a visible tip
`ActionEditTip`	Edit tip text
`ActionDeleteTip`	Delete tip from cell

Spreadsheet Functions (`/functions`)

File	Function	Description
`abs.js`	ABS	Returns absolute value
`acos.js`	ACOS	Returns arccosine
`angle.js`	ANGLE	Returns angle of point (x,y)
`asin.js`	ASIN	Returns arcsine
`atn.js`	ATN	Returns arctangent
`avg.js`	AVG	Calculates arithmetic mean
`ceil.js`	CEIL	Returns smallest integer ≥ x
`cos.js`	COS	Returns cosine
`cot.js`	COT	Returns cotangent
`count.js`	COUNT	Counts numeric values
`csc.js`	CSC	Returns cosecant
`date.js`	DATE	Returns current date
`deg.js`	DEG	Converts radians to degrees
`eps.js`	EPS	Returns machine epsilon
`exp.js`	EXP	Returns e^x
`floor.js`	FLOOR/INT	Returns largest integer ≤ x
`fp.js`	FP	Returns fractional part
`inf.js`	INF	Returns positive infinity
`ip.js`	IP	Returns integer part (truncate)
`log.js`	LOG	Returns natural logarithm
`log10.js`	LOG10	Returns base-10 logarithm
`max.js`	MAX	Returns maximum value
`min.js`	MIN	Returns minimum value
`mod.js`	MOD	Returns modulo
`pi.js`	PI	Returns π constant
`power.js`	POWER/POW	Raises number to a power
`rad.js`	RAD	Converts degrees to radians
`rmd.js`	RMD	Returns remainder
`rnd.js`	RND	Returns random number
`sec.js`	SEC	Returns secant
`sgn.js`	SGN	Returns sign (-1, 0, 1)
`sin.js`	SIN	Returns sine
`sqr.js`	SQR	Returns square root
`sum.js`	SUM	Sums all numeric values
`sumproduct.js`	SUMPRODUCT	Multiplies and sums products
`tan.js`	TAN	Returns tangent
`time.js`	TIME	Returns seconds since midnight
`vlookup.js`	VLOOKUP	Looks up values in a table

File Structure

.
├── actions
│   ├── ActionAddTip.js
│   ├── ActionCopy.js
│   ├── ActionCut.js
│   ├── ActionDeleteTip.js
│   ├── ActionEditTip.js
│   ├── ActionHideTip.js
│   ├── ActionMoveToBottom.js
│   ├── ActionMoveToLeft.js
│   ├── ActionMoveToRight.js
│   ├── ActionMoveToTop.js
│   ├── ActionPaste.js
│   ├── ActionShowTip.js
│   ├── ActionStepDown.js
│   ├── ActionStepLeft.js
│   ├── ActionStepRight.js
│   ├── ActionStepUp.js
│   ├── ExportCSVAction.js
│   ├── MoveFocusDownAction.js
│   ├── MoveFocusLeftAction.js
│   ├── MoveFocusRightAction.js
│   ├── MoveFocusUpAction.js
│   ├── OpenAction.js
│   ├── SaveAction.js
│   └── SelectAllCellsAction.js
├── classes
│   ├── AppController.js
│   ├── ASTEvaluator.js
│   ├── ASTNode.js
│   ├── CellsEditablesController.js
│   ├── CommandLine.js
│   ├── ComputationEngine.js
│   ├── DataHolder.js
│   ├── FormulaTokenizer.js
│   ├── FunctionRegistry.js
│   ├── MainMenu.js
│   ├── NavButtonsController.js
│   ├── PopupContextMenu.js
│   ├── SelectionDataHolder.js
│   ├── SelectionManager.js
│   ├── SelectionViewDrawer.js
│   ├── SheetView.js
│   ├── SimpleFormulaParser.js
│   ├── UITip.js
│   └── ViewModel.js
├── commandline.css
├── edt.css
├── edt.html
├── edt.js
├── functions
│   ├── abs.js
│   ├── acos.js
│   ├── angle.js
│   ├── asin.js
│   ├── atn.js
│   ├── avg.js
│   ├── ceil.js
│   ├── cos.js
│   ├── cot.js
│   ├── count.js
│   ├── csc.js
│   ├── date.js
│   ├── deg.js
│   ├── eps.js
│   ├── exp.js
│   ├── floor.js
│   ├── fp.js
│   ├── inf.js
│   ├── ip.js
│   ├── log10.js
│   ├── log.js
│   ├── max.js
│   ├── min.js
│   ├── mod.js
│   ├── pi.js
│   ├── power.js
│   ├── rad.js
│   ├── rmd.js
│   ├── rnd.js
│   ├── sec.js
│   ├── sgn.js
│   ├── sin.js
│   ├── sqr.js
│   ├── sum.js
│   ├── sumproduct.js
│   ├── tan.js
│   ├── time.js
│   └── vlookup.js
├── LICENSE
├── mainmenu.css
├── README.md
├── test.html
└── testing
    ├── tests.css
    └── tests.js

Testing

The application includes a comprehensive test suite (

test.html

) that validates all formula functionality:

111+ Test Cases covering arithmetic, cell references, functions, cross-sheet references, SUMPRODUCT, VLOOKUP, all mathematical functions, and exponentiation (POWER, POW, ^ operator)
100% Pass Rate on all test cases
Visual Test Results with green/red highlighting for pass/fail indicators
Report Generation for failed tests with copy to clipboard functionality
Filtering options (show all, passed only, failed only)

Run

test.html

from the HTTP server to validate the formula engine.

Version History

v1.8.0 (Current)

Added POWER and POW functions for exponentiation
Added caret operator (^) for inline exponentiation
Support for both comma (,) and semicolon (;) as argument separators in functions
Comprehensive edge case handling for exponentiation (0^0, negative bases with fractional exponents)
Added 31 new test cases for POWER, POW, and caret operator
Achieved 111 total test cases with 100% pass rate

v1.7.0

Added 30+ mathematical and utility functions
Added trigonometric functions: SIN, COS, TAN, COT, SEC, CSC
Added inverse trigonometric functions: ASIN, ACOS, ATN, ANGLE (ATAN2)
Added exponential and logarithmic functions: EXP, LOG, LOG10, SQR
Added integer functions: INT, FLOOR, CEIL, IP, FP
Added modulo functions: MOD, RMD
Added constants and utilities: PI, EPS, INF, DATE, TIME, RND
Added angle conversion functions: DEG, RAD
Added sign and absolute value functions: ABS, SGN
Enhanced cross-sheet range support with shorthand notation
Added comprehensive mathematical function documentation

v1.6.0

Added comprehensive selection system
Added column selection (click column headers)
Added row selection (click row headers)
Added individual cell selection (Ctrl+Click)
Added range selection (Shift+Arrow keys or Shift+Click)
Added Select All (Ctrl+A) with visual feedback
Added Clear Selection (Esc)
Added per-sheet selection persistence
Added selection status display
Added Selection menu in main menu bar
Added MoveFocus actions for keyboard navigation
Added SelectAllCellsAction
Improved viewport auto-scroll during selection
Enhanced visual feedback with color-coded selections

v1.5.0

Added Context Menu (right-click) with dynamic Tip management
Added Cell Tips feature with full CRUD operations
Added Copy, Cut, Paste functionality with metadata preservation
Added dynamic menu items based on tip state (Show/Hide toggle)
Added tip indicator (💡) on cells with tips
Added tip repositioning on scroll/resize
Added metadata persistence for tips in save/load
Added close button on tips to hide them

v1.4.0

Added Main Menu bar with File, Edit, View, Help menus
Added Command Line Interface with command history
Added File operations: Open/Save .edt files, Export to CSV
Added Navigation actions as modular components
Added keyboard shortcuts for all major operations
Added modal dialogs for About and Keyboard Shortcuts
Refactored styles into separate CSS files

v1.3.0

Refactored codebase into modular architecture with separate class files
Added dynamic class loading system
Added VLOOKUP function with exact and approximate match support

v1.2.0

Added SUMPRODUCT function with support for 2+ ranges
Enhanced cross-sheet reference support

v1.1.0

Added cross-sheet reference support
Implemented range references for all functions

v1.0.0

Initial release with basic arithmetic and spreadsheet functions
Viewport navigation and multiple sheet support
Dual mode display (formulas/results)

edt

Описание

Языки

Artem NazarovAdded POWER function 14 дней назадcfb67e2

Editable Table Viewport with Formula Support

Screenshots

Features

Mathematical Functions Reference

Absolute Value and Sign Functions

Power and Exponentiation Functions

Exponentiation Rules and Edge Cases

Trigonometric Functions (Radians)

Inverse Trigonometric Functions

Exponential and Logarithmic Functions

Angle Conversion Functions

Arithmetic and Modulo Functions

Constants and Utility Functions

Function Usage Examples

Selection System

Selection Methods

Selection Visual Feedback

Selection Status Display

Selection Persistence

Keyboard Navigation with Selection

Context Menu (Right-Click)

Edit Submenu

Tips Submenu

Tip Operations

Main Menu

File Menu

Edit Menu

Selection Menu

Navigation Menu

View Menu

Help Menu

Command Line Interface

Available Commands

File Commands

View Commands

Navigation Commands

Info Commands

System Commands

Command Line Features

Keyboard Shortcuts

File Operations

Edit Operations

Selection Operations

Navigation

System

Expressions and Spreadsheet Functions

Basic Arithmetic Expressions

Supported Operands

Spreadsheet Functions

SUM

AVG

MAX

MIN

COUNT

SUMPRODUCT

VLOOKUP

POWER / POW

Cell References

Single Cell Reference

Range Reference

Cross-Sheet References

Single Cell Cross-Sheet

Range Cross-Sheet (Shorthand)

Architecture

Core Components (/classes)

Actions (/actions)

Spreadsheet Functions (/functions)

File Structure

Testing

Version History

v1.8.0 (Current)

v1.7.0

v1.6.0

v1.5.0

v1.4.0

v1.3.0

Artem Nazarov
Added POWER function
14 дней назад
cfb67e2

Core Components (`/classes`)

Actions (`/actions`)

Spreadsheet Functions (`/functions`)