pattern.consequence — sicmutils 0.19.0

Code for defining and compiling 'consequence' functions, ie, functions from a binding map generated by a [pattern.match] to some successful transformation (or a failure!).

See pattern.rule for a detailed treatment.

compile-skeleton clj/s

(compile-skeleton frame-sym skel)

Takes:

• a symbol frame-sym meant to reference a map of bindings
• a skeleton expression skel

and returns an unevaluated body that, when evaluated, will produce a form structure of identical shape to skel, with:

• all variable binding forms replaced by forms that look up the binding in a map bound to frame-sym
• same with any segment binding form, with the added note that these should be spliced in
• any unquote or unquote-splicing forms respected.

succeed clj/s

(succeed x)

Wraps the argument x in a form that will always successfully return from a consequence function, whatever its value.

Use succeed to return nil or false from a consequence function. For all other return values, returning (succeed x) is identical to returning x

unwrap clj/s

(unwrap x)

Given a form returned by a consequence function, unwraps the top level succeed wrapper if present to return the final value.