package opam-0install

  1. Overview
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A context that reads opam files directly from an opam-repository checkout. It does not use a switch, and therefore does not pick up any pins the user has set. It also does not get any opam variables from the environment - instead, the caller must provide them explicitly.

include S.CONTEXT
type t
type rejection

A reason why a package can't be used as input to the solver. e.g. it is for a different platform, or conflicts with a user-provided constraint.

val pp_rejection : rejection Fmt.t

candidates t name is the list of available versions of name, in order of decreasing preference. If the user or environment provides additional constraints that mean a version should be rejected, include that here too. Rejects are only used for generating diagnostics reports. Candidates whose "availablity" field isn't satisfied must be rejected here.

val user_restrictions : t -> OpamPackage.Name.t -> OpamFormula.version_constraint option

user_restrictions t pkg is the user's constraint on pkg, if any. This is just used for diagnostics; you still have to filter them out yourself in candidates.

filter_deps t pkg f is used to pre-process depends and conflicts. pkg is the package which has the dependency f. For example, you can use this to filter out dependencies that are only needed on Windows if the platform is Linux.

val std_env : ?ocaml_native:bool -> ?sys_ocaml_version:string -> ?opam_version:string -> arch:string -> os:string -> os_distribution:string -> os_family:string -> os_version:string -> unit -> string -> OpamVariable.variable_contents option

std_env ~arch ~os ~os_distribution ~os_family ~os_version is an environment function that returns the given values for the standard opam variables, and None for anything else. If opam_version is not provided, use the version of the linked opam library.

val create : ?prefer_oldest:bool -> ?test:OpamPackage.Name.Set.t -> ?pins:(OpamTypes.version * OpamFile.OPAM.t) OpamTypes.name_map -> constraints:OpamFormula.version_constraint OpamTypes.name_map -> env:(string -> OpamVariable.variable_contents option) -> string -> t

create ~constraints ~env packages_dir is a solver that gets candidates from packages_dir, filtering them using constraints. packages_dir contains one sub-directory for each package name, each with subdirectories for each version, in the same format used by opam-repository.

  • parameter test

    Packages for which we should include "with-test" dependencies.

  • parameter pins

    Packages in this map have only the given candidate version and opam file.

  • parameter env

    Maps opam variable names to values (std_env may be useful here). "version" and the OpamPackageVar.predefined_depends_variables are handled automatically.

  • parameter prefer_oldest

    if true the solver is set to return the least up-to-date version of each package, if a solution exists. This is false by default.

  • before 0.4

    the prefer_oldest parameter did not exist.


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