Haskell

`haskell`

Callable singleton for the Haskell toolchain — access as hm.haskell.

Supports both object form (hm.haskell(ghc="9.6.7")) and bare form (hm.haskell.build(ghc="9.6.7", path="api"), etc.).

haskell(*, ghc=None, cabal='latest', image=None, base=None, path=None, cache_paths=None) -> HaskellToolchain | HaskellPackage

Parameter	Type	Default	Description
`ghc`	`str \| None`	`None`	GHC version to install (e.g. `"9.6.7"`). Required.
`cabal`	`str`	`'latest'`	cabal-install version. Defaults to `"latest"`.
`image`	`str \| None`	`None`	Local-mode Docker base image override.
`base`	`Step \| None`	`None`	Existing `Step` to attach to instead of emitting a fresh
apt-base step.
`path`	`str \| None`	`None`	Cabal package root. When provided, the call returns a
`HaskellPackage` directly rather than a toolchain.
`cache_paths`	`tuple[str, ...] \| None`	`None`	Override the cabal-file paths for deps-step cache
invalidation. Only meaningful when `path` is also set.

Returns HaskellToolchain | HaskellPackage — A HaskellToolchain when path is omitted, or a

`haskell.build()`

build(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`haskell.fmt()`

fmt(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`haskell.hlint()`

hlint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`haskell.lint()`

lint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`haskell.test()`

test(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellEntry`

Callable singleton for the Haskell toolchain — access as hm.haskell.

Supports both object form (hm.haskell(ghc="9.6.7")) and bare form (hm.haskell.build(ghc="9.6.7", path="api"), etc.).

`HaskellEntry.build()`

build(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellEntry.fmt()`

fmt(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellEntry.hlint()`

hlint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellEntry.lint()`

lint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellEntry.test()`

test(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellPackage`

One cabal package — returned by HaskellToolchain.package().

installed is the package's deps step (the chain ancestor every action leaf attaches to). Exposed so callers can chain custom commands onto the deps-installed snapshot via pkg.installed.sh(...).

Fields

Field	Type	Default
`path`	`str`	required
`installed`	`Step`	required

`HaskellPackage.build()`

build(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellPackage.fmt()`

fmt(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellPackage.hlint()`

hlint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellPackage.lint()`

lint(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellPackage.test()`

test(**kw) -> Step

Parameter	Type	Default	Description
`kw`	`Any`	`{}`	—

Returns Step

`HaskellToolchain`

Haskell toolchain install chain — constructed via hm.haskell().

Holds the shared ghcup install step. Spawn one HaskellPackage per cabal package via .package(path). All packages from one toolchain share the same ghcup-install step.

Fields

Field	Type	Default
`ghc`	`str`	required
`cabal_version`	`str`	required
`installed`	`Step`	required

`HaskellToolchain.cabal()`

cabal(path, *, cache_paths=None) -> HaskellPackage

Create a HaskellPackage for the cabal package at path.

Alias for .package(); reads more naturally for cabal projects.

Parameter	Type	Default	Description
`path`	`str`	required	Path to the cabal package root.
`cache_paths`	`tuple[str, ...] \| None`	`None`	Override the set of paths used for cache invalidation.

Returns HaskellPackage — A HaskellPackage ready for action methods.

`HaskellToolchain.package()`

package(path, *, cache_paths=None) -> HaskellPackage

Create a HaskellPackage for the cabal package at path.

Emits a cabal build all --only-dependencies step cached on the package's cabal files. Action methods on the returned package attach to that deps step.

Parameter	Type	Default	Description
`path`	`str`	required	Path to the cabal package root. Must contain a `*.cabal`
file and optionally a `cabal.project`.
`cache_paths`	`tuple[str, ...] \| None`	`None`	Override the set of paths used for cache invalidation.
Defaults to `(f"\{path\}/*.cabal", f"\{path\}/cabal.project")`.

Returns HaskellPackage — A HaskellPackage ready for action methods.

Examples

>>> import harmont as hm
>>> tc = hm.haskell(ghc="9.6.7")
>>> pkg = tc.package("api")
>>> hm.pipeline(pkg.build(), pkg.test())

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