Library Features

Library Features (Optional)

Core vs Library Features

Core CCL requires only parse and build_hierarchy. Everything in this document is optional library convenience built on top of Core CCL. Implementations can adapt these features to their language idioms.

Type-Safe Value Access

CCL values are always strings. Type conversion is a library convenience, not part of Core CCL.

Common Functions:

• get_string(config, path...) - Extract string values
• get_int(config, path...) - Parse integers with validation
• get_bool(config, path...) - Parse booleans (true/false, yes/no, 1/0)
• get_list(config, path...) - Extract lists from empty-key entries

Example:

app =
  name = MyApp
  port = 8080
  debug = true

name = get_string(config, "app", "name")     // "MyApp"
port = get_int(config, "app", "port")        // 8080
debug = get_bool(config, "app", "debug")     // true

Entry Processing

Manipulate CCL entries for composition and filtering.

Common Functions:

• filter(entries, predicate) - Remove entries (e.g., comments)
• compose(entries1, entries2) - Merge entry lists (Monoid composition)

Example:

/= Development config
database.host = localhost

/= Production overrides
database.host = prod.db.com

dev_entries = parse(dev_config)
prod_entries = parse(prod_config)
combined = compose(dev_entries, prod_entries)
final_config = build_hierarchy(combined)

Experimental Features

Some implementations provide additional experimental features:

Dotted Representation (Go implementation):

• Provides dotted access to hierarchical data
• get_string(config, "database.host") works for nested structure
• Both get_string(config, "database.host") and get_string(config, "database", "host") access same data

Test Suite Coverage

The CCL Test Suite provides tests for these features:

• Type-Safe Access: 107 assertions (22 tests)
• Entry Processing: 67 assertions (19 tests)
• Experimental Features: 18 tests for dotted representation

See Test Suite Guide for progressive implementation roadmap.