# Module Alpha

    module Alpha: sig .. end

ALPHA conversion

    type 'a undoAlphaElement

This is the type of the elements that are recorded by the alpha conversion functions in order to be able to undo changes to the tables they modify. Useful for implementing scoping

    type 'a alphaTableData

This is the type of the elements of the alpha renaming table. These elements can carry some data associated with each occurrence of the name.

    val newAlphaName : alphaTable:(string, 'a alphaTableData ref) Hashtbl.t ->
           undolist:'a undoAlphaElement list ref option ->
           lookupname:string -> data:'a -> string * 'a

Create a new name based on a given name. The new name is formed from a prefix (obtained from the given name by stripping a suffix consisting of ___ followed by up to 9 digits), followed by a special separator and then by a positive integer suffix. The first argument is a table mapping name prefixes to some data that specifies what suffixes have been used and how to create the new one. This function updates the table with the new largest suffix generated. The "undolist" argument, when present, will be used by the function to record information that can be used by `Alpha.undoAlphaChanges` to undo those changes. Note that the undo information will be in reverse order in which the action occurred. Returns the new name and, if different from the lookupname, the location of the previous occurrence. This function knows about the location implicitly from the `Cil.currentLoc`.

    val registerAlphaName : alphaTable:(string, 'a alphaTableData ref) Hashtbl.t ->
           undolist:'a undoAlphaElement list ref option ->
           lookupname:string -> data:'a -> unit

Register a name with an alpha conversion table to ensure that when later we call newAlphaName we do not end up generating this one

    val docAlphaTable : unit ->
           (string, 'a alphaTableData ref) Hashtbl.t -> Pretty.doc

Split the name in preparation for newAlphaName. The prefix returned is used to index into the hashtable. The next result value is a separator (either empty or the separator chosen to separate the original name from the index)

    val getAlphaPrefix : lookupname:string -> string

    val undoAlphaChanges : alphaTable:(string, 'a alphaTableData ref) Hashtbl.t ->
           undolist:'a undoAlphaElement list -> unit

Undo the changes to a table