+(define %distro-root-directory
+ ;; Absolute file name of the module hierarchy.
+ (dirname (search-path %load-path "guix.scm")))
+
+(define %service-type-path
+ ;; Search path for service types.
+ (make-parameter `((,%distro-root-directory . "gnu/services")
+ (,%distro-root-directory . "gnu/system"))))
+
+(define (all-service-modules)
+ "Return the default set of service modules."
+ (cons (resolve-interface '(gnu services))
+ (all-modules (%service-type-path)
+ #:warn warn-about-load-error)))
+
+(define* (fold-service-types proc seed
+ #:optional
+ (modules (all-service-modules)))
+ "For each service type exported by one of MODULES, call (PROC RESULT). SEED
+is used as the initial value of RESULT."
+ (fold-module-public-variables (lambda (object result)
+ (if (service-type? object)
+ (proc object result)
+ result))
+ seed
+ modules))
+
+(define lookup-service-types
+ (let ((table
+ (delay (fold-service-types (lambda (type result)
+ (vhash-consq (service-type-name type)
+ type result))
+ vlist-null))))
+ (lambda (name)
+ "Return the list of services with the given NAME (a symbol)."
+ (vhash-foldq* cons '() name (force table)))))
+