Optional Braces Example

This example demonstrates that {{ }} braces are optional for direct expressions but required for string interpolation.

Key Features

✅ Direct Expressions (Braces Optional)

You can write expressions without {{ }}:

# Function calls
prompt: get('q')
count: get('items').length

# Arithmetic
total: price * quantity
average: sum / count

# Comparisons
isAdult: age >= 18
isValid: status == "active"

✅ String Interpolation (Braces Required)

When interpolating within strings, you must use {{ }}:

# Single interpolation
message: "Hello {{ get('name') }}"

# Multiple interpolations
greeting: "Score: {{ get('score') }} out of {{ get('total') }}"

# With function calls
result: "Query result: {{ get('q') }}"

Syntax Rules

Context	Braces	Example
Direct value	Optional	prompt: get('q')
String interpolation	Required	message: "Hello {{ get('name') }}"
Literal value	Not needed	age: 25

When to Use What

Use WITHOUT Braces (Cleaner)

# When assigning a direct value
count: get('items').length
valid: age >= 18
result: get('data')

Use WITH Braces (For Interpolation)

# When building strings with dynamic values
message: "You have {{ get('count') }} items"
url: "https://api.example.com/users/{{ get('userId') }}"

See Also

• examples/jinja2-expressions/ - Jinja2 YAML preprocessing
• examples/hybrid-expressions/ - Mixing function calls and dot notation
• examples/control-flow/ - Control flow patterns