Sheety

Sheety is an Excel-like spreadsheet library for Crystal that parses formulas, evaluates expressions, and generates standalone binaries using Croupier for task-based dependency tracking.

Features

• Excel Formula Parser: Parses a comprehensive subset of Excel formulas

  • Arithmetic: +, -, *, /, ^
  • Comparison: =, <, >, <=, >=, <>
  • Text: & (concatenation)
  • Logical: IF, AND, OR, NOT
  • Functions: SUM, AVERAGE, MIN, MAX, COUNT, ROUND, ABS, CONCAT, LEFT, RIGHT, MID, LEN, UPPER, LOWER
  • Cell references: A1, Sheet2!B5
  • Ranges: A1:B5, Sheet1!A1:A10

• Dependency Tracking: Uses Croupier to track dependencies and only recalculate affected cells

• Interactive Mode: Generated binaries support interactive REPL for modifying cell values

• Spreadheet Display: Shows results in a proper grid layout using Tablo

Installation

Add the dependency to your shard.yml:

dependencies:
  sheety:
    github: ralsina/sheety

Then run:

shards install

Usage

Command Line

Sheety provides a CLI for compiling spreadsheet definitions into standalone binaries:

# Compile a spreadsheet YAML to a Crystal binary
sheety compile examples/test_sheet.yaml

# Run the generated binary (interactive mode by default)
./test_sheet

Spreadsheet YAML Format

Define your spreadsheet in YAML:

Sheet1:
  A1:
    value: 100
  A2:
    value: 200
  A3:
    value: 300
  A4:
    formula: "=SUM(A1:A3)"
  A5:
    formula: "=AVERAGE(A1:A3)"
  B1:
    value: "Hello"
  B2:
    value: "World"
  B3:
    formula: "=CONCAT(B1, \" \", B2)"
  C1:
    value: 5
  C2:
    value: 3
  C3:
    formula: "=IF(C1>C2, \"Yes\", \"No\")"

Sheet2:
  A1:
    value: 100
  A2:
    formula: "=Sheet1!A4*2"

Interactive Mode

When you run the generated binary, you enter interactive REPL mode:

=== Spreadsheet Results ===
[... table display ...]

=== Interactive Mode ===
Enter cell assignments (e.g., A1=123, Sheet2!B5=hello)
Commands: 'quit' or 'exit' to quit, 'show' to refresh display

> A1=999
Set Sheet1!A1 = 999
[... updated table with recalculated formulas ...]

> quit
Goodbye!

Programmatic Usage

require "sheety"

generator = Sheety::CroupierGenerator.new

# Add formulas
generator.add_formula("A1", "=SUM(B1:B10)")
generator.add_formula("C5", "=AVERAGE(A1:A100)", "Sheet2")

# Generate source code with initial values
initial_values = {
  "Sheet1!B1" => 10.0,
  "Sheet1!B2" => 20.0,
}
source = generator.generate_source(initial_values, interactive: true)

# Write and compile
File.write("my_sheet.cr", source)
`crystal build my_sheet.cr`

Development

Running Tests

crystal spec

Building

shards build

Examples

See the examples/ directory for sample spreadsheet definitions.

Current Status

• ✅ Excel formula parsing with 186 passing tests
• ✅ AST generation for all formula types
• ✅ Code generation for Croupier tasks
• ✅ Cell reference and range support
• ✅ Multi-sheet support
• ✅ Excel function implementations
• ✅ Interactive REPL mode
• ✅ Spreadsheet grid display with Tablo
• ✅ Dependency tracking with Croupier
• ✅ Automatic recalculation on value changes

License

MIT

Contributors

• Roberto Alsina - creator and maintainer