17.15 Sanitizing bindings

This compiler pass makes sure that every clamba struct appears as direct right–hand side expression in a fix struct:

(fix ((?lhs ?clambda)) ?body)

The following bindings are exported by the library (vicare compiler).

Function: pass-sanitize-bindings input

Perform code transformations traversing the whole hierarchy in input, which must be a struct instance representing recordised code, and building a new hierarchy of recordised code; return the new hierarchy.

Perform the following transformations:

• clambda structs that already appear as RHS of fix structs are left alone.
• clambda structs appearing as RHS in single–binding bind structs cause the bind struct to be replaced by a fix struct:

  (bind ((?lhs ?clambda)) ?body)
  → (fix ((?lhs ?clambda)) ?body)
  

• clambda structs appearing as RHS in multiple–binding bind structs cause the bind struct to be split into a bind struct and a fix struct in which the bindings are partitioned:

  (bind ((?lhs0 ?clambda)
         (?lhs1 ?rhs))
    ?body)
  → (bind ((?lhs1 ?rhs))
        (fix ((?lhs0 ?clambda))
          ?body))
  

• clambda structs appearing as standalone expressions (that is: not directly as RHS of a bind or fix struct) are “lifted” as follows:

  (clambda (?formals ?body) ...)
  → (fix ((tmp (clambda (?formals ?body) ...)))
        tmp)
  

In the returned struct of recordised code: all the clambda structs appear in the code as right–hand side initialisation expressions of fix structs; all the bind structs have a non–clambda struct as right–hand side initialisation expression.