Library usage

[ceving]

Is it possible to use Mangle as a library? Is there an example how to build facts and rules in order to execute queries?

I have the following example and I would like to execute the queries from Go.

# ===== BASIC ENTITIES =====
# Users
user("alice").
user("bob").
user("charlie").
user("diana").
# User Roles
user_role("admin").
user_role("editor").
user_role("viewer").
user_role("moderator").
# Permissions
permission("read_posts").
permission("write_posts").
permission("delete_posts").
permission("manage_users").
permission("view_analytics").
permission("moderate_content").
# Permission Roles (groups of permissions)
permission_role("content_manager").
permission_role("user_manager").
permission_role("basic_access").
permission_role("analytics_access").
# ===== RELATIONSHIPS =====
# Users have User Roles
user_has_role("alice", "admin").
user_has_role("bob", "editor").
user_has_role("charlie", "viewer").
user_has_role("diana", "moderator").
# Permissions belong to Permission Roles
permission_in_role("read_posts", "basic_access").
permission_in_role("write_posts", "content_manager").
permission_in_role("delete_posts", "content_manager").
permission_in_role("manage_users", "user_manager").
permission_in_role("view_analytics", "analytics_access").
permission_in_role("moderate_content", "content_manager").
# User Roles are assigned Permission Roles
user_role_has_permission_role("admin", "content_manager").
user_role_has_permission_role("admin", "user_manager").
user_role_has_permission_role("admin", "basic_access").
user_role_has_permission_role("admin", "analytics_access").
user_role_has_permission_role("editor", "content_manager").
user_role_has_permission_role("editor", "basic_access").
user_role_has_permission_role("viewer", "basic_access").
user_role_has_permission_role("moderator", "content_manager").
user_role_has_permission_role("moderator", "basic_access").
# ===== INFERENCE RULES =====
# A user has a permission if:
# 1. The user has a user role
# 2. That user role has a permission role  
# 3. The permission is in that permission role
user_has_permission(User, Permission) ⟸
    user_has_role(User, UserRole),
    user_role_has_permission_role(UserRole, PermissionRole),
    permission_in_role(Permission, PermissionRole).
# Role hierarchy: some user roles can inherit from others
# For example, admin inherits all permissions from editor
user_role_inherits("admin", "editor").
user_role_inherits("admin", "moderator").
user_role_inherits("editor", "viewer").
# Transitive inheritance
user_role_inherits(Role1, Role3) ⟸
    user_role_inherits(Role1, Role2),
    user_role_inherits(Role2, Role3).
# Users inherit permissions through role hierarchy
user_has_permission(User, Permission) ⟸
    user_has_role(User, UserRole1),
    user_role_inherits(UserRole1, UserRole2),
    user_role_has_permission_role(UserRole2, PermissionRole),
    permission_in_role(Permission, PermissionRole).
# Administrative queries: Who can perform specific actions?
can_manage_users(User) ⟸
    user_has_permission(User, "manage_users").
can_delete_posts(User) ⟸
    user_has_permission(User, "delete_posts").
can_view_analytics(User) ⟸
    user_has_permission(User, "view_analytics").
# Security queries: What permissions does a user have?
all_user_permissions(User, Permission) ⟸
    user_has_permission(User, Permission).
# Audit queries: Which users have access to sensitive operations?
sensitive_permission("manage_users").
sensitive_permission("delete_posts").
sensitive_permission("view_analytics").
users_with_sensitive_access(User, Permission) ⟸
    sensitive_permission(Permission),
    user_has_permission(User, Permission).
# Resource-based permissions (extended example)
resource("post1").
resource("post2").
resource("user_profile_alice").
# Context-sensitive permissions
user_owns_resource("alice", "user_profile_alice").
user_owns_resource("bob", "post1").
user_owns_resource("charlie", "post2").
# Users can always modify their own resources
user_can_modify_resource(User, Resource) ⟸
    user_owns_resource(User, Resource).
# Users with delete_posts permission can modify any post
user_can_modify_resource(User, Resource) ⟸
    user_has_permission(User, "delete_posts"),
    resource(Resource),
    Resource != "user_profile_alice".  # Assuming posts don't include user profiles
# ===== EXAMPLE QUERIES =====
# Find all permissions for alice:
# ? user_has_permission("alice", Permission).
# Find who can manage users:
# ? can_manage_users(User).
# Find all users with sensitive permissions:
# ? users_with_sensitive_access(User, Permission).
# Check if bob can delete posts:
# ? can_delete_posts("bob").
# Find what resources charlie can modify:
# ? user_can_modify_resource("charlie", Resource).

[burakemir]

Certainly. Check out the mangle service, in particular these bits here that parse, analyze, stratify and evaluate your program.

You can also programmatically defined rules and facts, instead of parsing in source form. You'd need to follow the same steps (analyze, stratify, evaluate with a store).