null

Null Operator Examples

The null operator in Graft is used to check if a value is null, empty, or undefined. It returns true if the value is considered "null-like" and false otherwise.

Overview

The (( null <reference> )) operator evaluates to:

• true if the reference is:
  • null or nil
  • An empty string ""
  • An empty array []
  • An empty map {}
  • A non-existent key (undefined)
• false for any other value

Files in this Directory

1. basic.yml - Basic null checking examples
2. conditional-config.yml - Using null checks in conditional configurations
3. default-values.yml - Providing defaults for null values
4. validation.yml - Data validation using null checks

Common Use Cases

• Checking if optional configuration is provided
• Validating required fields
• Providing default values when configuration is missing
• Conditional resource creation based on presence of values
• Data validation in complex configurations

Running the Examples

# Check basic null operations
graft merge basic.yml

# Conditional configuration based on null checks
graft merge conditional-config.yml

# Default value handling
graft merge default-values.yml

# Data validation examples
graft merge validation.yml

Key Concepts

1. Empty vs Null: The operator treats empty collections the same as null
2. Undefined References: Non-existent keys are considered null
3. Type Coercion: No type coercion occurs - only truly empty/null values return true
4. Combination with Ternary: Often used with ?: operator for conditional logic