Error Handling¶

LeonBasic provides error handling capabilities using the try-catch mechanism, allowing you to gracefully handle exceptions that may occur during program execution.

1. try-catch Exception Handling¶

require("basic");
try {
    var(a) = int:5 / int:0;
} catch(error) {
    basic.print(string:"Error occurred: " + error);
}

2. Common Error Types¶

Here are some common errors you might encounter in LeonBasic:

Division by zero errors
File not found errors
Type mismatch errors
Network connection errors
Module loading errors

3. Handling File Operation Errors¶

require("basic");
try {
    var(file) = basic.open("nonexistent_file.txt", "read");
    var(content) = basic.read(file);
    basic.close(file);
} catch(error) {
    basic.print(string:"File operation error: " + error);
}

4. Handling Network Errors¶

require("basic");
require("request");
try {
    var(response) = request.get("https://unreachable-site.com");
    basic.print(response);
} catch(error) {
    basic.print(string:"Network error: " + error);
}

5. Handling Type Errors¶

require("basic");
try {
    // Attempting to concatenate incompatible types
    var(result) = string:"Hello" + int:123;
    basic.print(var(result));
} catch(error) {
    basic.print(string:"Type error: " + error);
}

6. Nested try-catch Blocks¶

You can nest try-catch blocks to handle errors at different levels:

require("basic");
try {
    // Outer try block
    var(file) = basic.open("data.txt", "read");
    try {
        // Inner try block
        var(content) = basic.read(file);
        var(invalid_operation) = int:10 / int:0;
    } catch(inner_error) {
        basic.print(string:"Error processing file content: " + inner_error);
    }
    basic.close(file);
} catch(outer_error) {
    basic.print(string:"Error opening or closing file: " + outer_error);
}

7. Best Practices for Error Handling¶

Always wrap operations that might fail (file operations, network requests, divisions) in try-catch blocks
Provide meaningful error messages to help with debugging
Ensure resources are properly released even when errors occur (e.g., close files)
Consider implementing error recovery strategies where appropriate
Log errors for troubleshooting purposes