module OpamFilter: sig .. end
Manage filters
val to_string : OpamTypes.filter -> string
Pretty-print
val fold_down_left : ('a -> OpamTypes.filter -> 'a) -> 'a -> OpamTypes.filter -> 'a
Folds on the tree of a filter
val variables : OpamTypes.filter -> OpamTypes.full_variable list
Returns all the variables appearing in a filter (including the ones within
    string interpolations
type OpamTypes.full_variable -> OpamTypes.variable_contents option 
Type of filter environment.
type OpamTypes.name list * OpamTypes.variable * (string * string) option 
The type of filter idents with (optionally multiple) qualifying package
    names and optional string converter
val expand_string : env -> string -> string
Rewrites string interpolations within a string
val eval : ?default:OpamTypes.variable_contents ->
       env -> OpamTypes.filter -> OpamTypes.variable_contents
Computes the value of a filter. May raise Failure if default isn't
    provided
val eval_to_bool : ?default:bool -> env -> OpamTypes.filter -> bool
Like to_value but casts the result to a bool. Raises Invalid_argument if
    not a valid bool and no default supplied.
val opt_eval_to_bool : env -> OpamTypes.filter option -> bool
Same as eval_to_bool, but takes an option as filter and returns always
    true on None, false when the filter is Undefined. This is the
    most common behaviour for using "filters" for filtering
val eval_to_string : ?default:string -> env -> OpamTypes.filter -> string
Like to_value but casts the result to a string
val ident_of_var : OpamTypes.full_variable -> fident
Wraps a full_variable into a fident accessor
val ident_value : ?default:OpamTypes.variable_contents ->
       env -> fident -> OpamTypes.variable_contents
Resolves a filter ident. Like eval, may raise Failure if no default is
    provided
val ident_string : ?default:string -> env -> fident -> string
Like ident_value, but casts the result to a string
val ident_bool : ?default:bool -> env -> fident -> bool
Like ident_value, but casts the result to a bool
val expand_interpolations_in_file : env -> OpamTypes.basename -> unit
Rewrites basename.in to basename, expanding interpolations
val commands : env -> OpamTypes.command list -> string list list
Processes filters evaluation in a command list: parameter expansion and
    conditional filtering
val single_command : env -> OpamTypes.arg list -> string list
Process a simpler command, without filters
val commands_variables : OpamTypes.command list -> OpamTypes.full_variable list
Extracts variables appearing in a list of commands