Info.md

Cabal Status Command Specification

Describes how we expect the command cabal status to behave from a high-level perspective.

CompilerInfo

> cabal status --output-format=json --compiler | jq
{
  "cabal-version": "3.7.0.0",
  "compiler": {
    "flavour": "GHC",
    "compiler-id": "ghc-7.10.2",
    "path": "/usr/bin/ghc"
  }
}

Cli:

• --output-format is mandatory. Only allowed value: json (may be extended in the future)
• --compiler composable selector

Output explanations:

• Mandatory: cabal-version denotes the output format version and follows the cabal-version scheme
• compiler-id is standardised to: <Compiler-Name>-<Version>
• path points to the same location cabal is using
• flavour is one of: GHC | GHCJS

Do we care about more fields?

BuildInfo

Syntax:

> cabal status --output-format=json --target=./src/File.hs --target=./test/Main.hs --target=./non-existent/Main.hs | jq
{
  "cabal-version": "3.7.0.0",
  "target": [
    { 
      "target": "./src/File.hs",
      "unit-id": "foo-inplace"
    },
    { 
      "target": "./test/Main.hs",
      "unit-id": "foo-testsuite-inplace"
    },
    { 
      "target": "./non-existent/Main.hs",
      "unit-id": null
    }
  ]
}

Cli:

• --output-format is mandatory. Only allowed value: json (may be extended in the future)
• --target can be given multiple times
  • argument is expected to be a cabal target, thus we allow: components (in all valid specifications), file-targets

Output explanations:

• Mandatory: cabal-version denotes the output format version and follows the cabal-version scheme
• target, list of json object containing the relevant information
  • Original target parameter is the key in the json object
  • unit-id of the target string
  • If unit-id is null, no such target

More usage examples

Flags are composable and results are reported as one json object.

> cabal status --output-format=json --compiler --target=./src/File.hs --target=./test/Main.hs --target=./non-existent/Main.hs | jq
{
  "version": "3.7.0.0",
  "compiler": {
    "flavour": "GHC",
    "compiler-id": "ghc-7.10.2",
    "path": "/usr/bin/ghc"
  },
  "targets": [
    { 
      "target": "./src/File.hs",
      "unit-id": "foo-inplace"
    },
    { 
      "target": "./test/Main.hs",
      "unit-id": "foo-testsuite-inplace"
    },
    { 
      "target": "./non-existent/Main.hs",
      "unit-id": null
    }
  ]
}

---

Only one test

> cabal status --output-format=json --target=tests | jq
{
  "version": "3.7.0.0",
  "targets": [
    { 
      "target": "tests",
      "unit-id": "foo-tests-inplace"
    }
  ]
}

---

Multiple executables, thus exes resolves to multiple targets

> cabal status --output-format=json --target=exes | jq
{
  "version": "3.7.0.0",
  "compiler": {
    "flavour": "GHC",
    "compiler-id": "ghc-7.10.2",
    "path": "/usr/bin/ghc"
  },
  "targets": [
    { 
      "target": "exes",
      "unit-id": "foo-exe1-inplace"
    },
    { 
      "target": "exes",
      "unit-id": "foo-exe2-inplace"
    }
  ]
}