DSL Implementations

Ruler provides five distinct DSL implementations for different use cases. Each produces the same Ruler operators but with syntax optimized for specific contexts.

Quick Comparison

Feature	Wirefilter	JMESPath	Natural Language	MongoDB Query	GraphQL Filter
Comparison	✅ Full	✅ Full	✅ Full	✅ Full + Strict	✅ Full
Logical Ops	✅ Full	✅ Full	✅ Full	✅ Full + XOR/NAND	✅ Full
Arithmetic	✅ Yes	❌ No	❌ No	❌ No	❌ No
String Ops	✅ Regex	⚠️ Limited	⚠️ Limited	✅ Full	✅ Good
Action Callbacks	✅ Yes	❌ No	❌ No	❌ No	❌ No
Strict Equality	✅ Yes	⚠️ Workaround	❌ No	✅ Yes	❌ No

Wirefilter DSL

SQL-like text syntax. Best for developers and stored rules.

use Cline\Ruler\DSL\Wirefilter\StringRuleBuilder;

$srb = new StringRuleBuilder;
$rule = $srb->parse('age >= 18 and country == "US"');
$rule = $srb->parse('price + shipping > 100');  // Arithmetic supported

Best for: Developer-facing rules, config files, arithmetic expressions

JMESPath DSL

AWS-style JSON path expressions. Follows JMESPath standard.

use Cline\Ruler\DSL\JMESPath\JMESPathRuleBuilder;

$builder = new JMESPathRuleBuilder;
$rule = $builder->parse('age >= `18` && country == \'US\'');

Syntax notes:

• Use backticks for numbers: `18`
• Use &&, ||, ! (not and, or, not)
• Supports contains(), starts_with(), ends_with()

Best for: AWS integrations, JSON document filtering

Natural Language DSL

Human-readable expressions for business users.

use Cline\Ruler\DSL\NaturalLanguage\NaturalLanguageRuleBuilder;

$builder = new NaturalLanguageRuleBuilder;
$rule = $builder->parse('age is at least 18 and country is "US"');
$rule = $builder->parse('status is not "banned"');

Operators:

• is, is not — equality
• is more than, is greater than — greater than
• is at least, is X or more — greater than or equal
• is less than — less than
• is at most, is X or less — less than or equal

Best for: Non-technical stakeholders, business rule management

MongoDB Query DSL

JSON-based query syntax compatible with MongoDB.

use Cline\Ruler\DSL\MongoDB\MongoDBRuleBuilder;

$builder = new MongoDBRuleBuilder;
$rule = $builder->parse('{"age": {"$gte": 18}, "country": "US"}');
$rule = $builder->parse('{"$or": [{"age": {"$gte": 21}}, {"vip": true}]}');

Extended operators:

• $same, $nsame — strict equality (===, !==)
• $between — range check
• $xor, $nand, $nor — advanced logical
• $regex, $contains, $startsWith, $endsWith — string operations
• Case-insensitive variants: $containsi, $startsWithi, $endsWithi

Best for: REST APIs, NoSQL databases, microservices

GraphQL Filter DSL

JSON syntax following GraphQL filter conventions.

use Cline\Ruler\DSL\GraphQL\GraphQLFilterRuleBuilder;

$builder = new GraphQLFilterRuleBuilder;
$rule = $builder->parse('{"age": {"gte": 18}, "country": "US"}');
$rule = $builder->parse('{"OR": [{"age": {"gte": 21}}, {"vip": true}]}');

Syntax notes:

• No $ prefix on operators
• Uppercase AND, OR, NOT
• Supports contains, startsWith, endsWith, match (regex)

Best for: GraphQL APIs, Hasura/Prisma integrations, frontend developers

Choosing a DSL

Use Case	Recommended DSL
Config files with calculations	Wirefilter
AWS/JSON document filtering	JMESPath
Business stakeholder rules	Natural Language
REST API query parameters	MongoDB Query
GraphQL API filters	GraphQL Filter
Rules with action callbacks	Wirefilter
Maximum string operations	MongoDB Query
Type-strict comparisons	Wirefilter or MongoDB

Workaround for Non-Arithmetic DSLs

Pre-compute values in context:

$context = new Context([
    'total' => $price + $shipping,  // Compute outside DSL
]);

// Then use the pre-computed value
$builder->parse('{"total": {"$gt": 100}}');