Albatross.Expression.Utility 5.0.0

Albatross.Expression.Utility

A command-line interface (CLI) tool for evaluating mathematical and logical expressions with support for variable management. Built on the powerful Albatross.Expression library, this utility provides an interactive way to work with expressions and store reusable variables.

Features

• Expression Evaluation: Evaluate complex mathematical, logical, and string expressions
• Variable Management: Store, retrieve, list, and remove named variables for reuse
• Persistent Storage: Variables are automatically saved to local application data directory
• Rich Expression Support: Leverage all capabilities of the Albatross.Expression library including:
  • Mathematical operations (arithmetic, trigonometric, statistical)
  • String manipulation functions
  • Date/time operations
  • Logical operations and comparisons
  • Array operations
  • Regular expression support
• Command Aliases: Short aliases for faster command execution
• Cross-platform: Works on Windows, macOS, and Linux

Prerequisites

• .NET 8.0 SDK or later
• Command-line interface (Terminal, PowerShell, etc.)

Installation

Option 1: Install as Global .NET Tool (Recommended)

dotnet tool install -g Albatross.Expression.Utility

Option 2: Build from Source

git clone https://github.com/RushuiGuan/expression.git
cd expression
dotnet restore
dotnet build
dotnet pack Albatross.Expression.Utility
dotnet tool install -g --add-source ./Albatross.Expression.Utility/bin/Debug Albatross.Expression.Utility

Usage

The tool is invoked using the ex command followed by subcommands:

ex <command> [options] [arguments]

Commands

eval - Evaluate an Expression

Evaluate a mathematical, logical, or string expression.

Syntax:

ex eval <expression>
ex e <expression>    # Short alias

Examples:

# Mathematical expressions
ex eval "2 + 3 * 4"
# Output: 14

ex eval "sqrt(16) + power(2, 3)"
# Output: 12

# String operations
ex eval "concat('Hello', ' ', 'World')"
# Output: Hello World

# Date operations
ex eval "year(now())"
# Output: 2024

# Logical expressions
ex eval "5 > 3 and 2 < 10"
# Output: True

set - Set a Variable

Store a variable with a name and expression value.

Syntax:

ex set -n <name> -v <expression>
ex s -n <name> -v <expression>    # Short alias

Examples:

# Set numeric variables
ex set -n pi -v 3.14159
ex set -n radius -v 5

# Set expression variables
ex set -n area -v "pi * power(radius, 2)"

# Set string variables
ex set -n greeting -v "concat('Hello, ', 'World!')"

list - List All Variables

Display all stored variables with their values.

Syntax:

ex list
ex l    # Short alias

Example:

ex list

Output:

Name     Value
----     -----
pi       3.14159
radius   5
area     pi * power(radius, 2)
greeting concat('Hello, ', 'World!')

read - Read a Variable

Read and evaluate a stored variable.

Syntax:

ex read <variable_name>
ex r <variable_name>    # Short alias

Examples:

ex read pi
# Output: 3.14159

ex read area
# Output: 78.53975 (calculated using stored pi and radius values)

remove - Remove a Variable

Delete a stored variable.

Syntax:

ex remove <variable_name>

Examples:

ex remove pi
ex remove area

Working with Variables

Variables are automatically resolved when evaluating expressions. This allows you to build complex calculations step by step:

# Step 1: Set base values
ex set -n length -v 10
ex set -n width -v 5
ex set -n height -v 3

# Step 2: Calculate intermediate values
ex set -n area -v "length * width"
ex set -n volume -v "area * height"

# Step 3: Use in expressions
ex eval "volume * 2"
# Output: 300

# Step 4: View all variables
ex list

Advanced Expression Examples

# Complex mathematical expressions
ex eval "sin(pi/2) + cos(0)"
# Output: 2

# String manipulation
ex eval "upper(left('hello world', 5))"
# Output: HELLO

# Conditional logic
ex eval "if(5 > 3, 'yes', 'no')"
# Output: yes

# Date calculations
ex eval "dayOfWeek(today())"
# Output: Monday (example)

# Array operations
ex eval "array(1, 2, 3, 4, 5)"
# Output: [1, 2, 3, 4, 5]

Data Storage

Variables are stored as text files in your local application data directory:

• Windows: %LOCALAPPDATA%\Albatross.Expression.Utility\
• macOS: ~/.local/share/Albatross.Expression.Utility/
• Linux: ~/.local/share/Albatross.Expression.Utility/

Each variable is stored as a separate .txt file containing the expression definition.

Error Handling

The tool provides clear error messages for common issues:

• Invalid expression syntax
• Undefined variables
• Invalid variable names
• Mathematical errors (division by zero, etc.)

Documentation

For Api Reference, visit: https://rushuiguan.github.io/expression/

License

This project is licensed under the MIT License - see the LICENSE file for details.

Related Projects

• Albatross.Expression - The core expression parsing and evaluation library
• Albatross.CommandLine - Command-line framework used by this utility

Contributing

Contributions are welcome! Please feel free to submit a Pull Request or open an Issue for bugs, features, or questions.