version 1 .
embeddedType EntityRef.Cap .

# Gatekeeper step to access a Nix store.
NixResolveStep = <nix @detail NixResolveDetail> .

NixResolveDetail = { }
& @lookupPath  LookupPath
& @storeUri    StoreUri
& @storeParams StoreParams
& @cacheSpace  CacheSpace
.

# List of strings corresponding to entries in NIX_PATH.
# For example:
#  [ "nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos"
#    "nixos-config=/etc/nixos/configuration.nix"
#    "/nix/var/nix/profiles/per-user/root/channels"
#  ]
LookupPath = @lookupPath { lookupPath: [string ...] } / @absent { } .

StoreUri = @storeUri { storeUri: string } / @absent { } .

StoreParams = @storeParams { storeParams: AttrSet } / @absent { } .

# A cooperative caching dataspace shared with other Nix stores.
CacheSpace = @cacheSpace { cache: #:any } / @absent { } .

# Assertion.
CheckStorePath = <check-path @path string @valid #:bool> .

# Represents a Nix derivation. The @value can be realised via @context.
Derivation = <drv @value any @context any> .

# Assertion. The store that this asserted to will copy the closure of @storePath to @destination. When the copy completes or fails a Result value is asserted to @result.
CopyClosure = <copy-closure @dest #:any @storePath string @result #:Result>.

# Assertion.
# Eval at a Nix value capability.
# @expr must be a function that takes two parameters,
# the first is @args and the second is the value of
# the previous evaluation.
# A new Nix value capability is return via @result.
# This capability can be observed using the Dataspace
# protocol but store paths may not be locally available.
Eval = <eval @expr string @args any @result #:Result> .

# Assertion.
# Realise a Nix value capability returned from <eval …> to a string.
RealiseString = <realise-string @result #:Result> .

AttrSet = {symbol: any ...:...} .

# Value.
Result = Error / <ok @value any>.

# Common error type.
Error = <error @message any>.