effect-facet-unstable-cli-argument

name: effect-facet-unstable-cli-argument description: Guidance for facet effect/unstable/cli/Argument focused on APIs like map, filter, and filterMap. Load after effect-skill-router when this facet is the primary owner.

Effect Facet unstable/cli/Argument

Owned scope

• Owns only effect/unstable/cli/Argument.
• Parent module: effect/unstable/cli.
• Source anchor: packages/effect/src/unstable/cli/Argument.ts.

What it is for

• Module-specific APIs and usage patterns for Effect programs.

API quick reference

• map
• filter
• filterMap
• mapEffect
• mapTryCatch
• date
• file
• none
• path
• float
• atMost
• choice
• orElse
• string
• atLeast
• between
• integer
• Argument
• Full API list: references/api-reference.md

How to use it

• Prefer pipe-based composition to keep transformations explicit and testable.
• Assume unstable APIs can evolve quickly; isolate usage behind thin local adapters.
• Use the reference docs to select the smallest API surface that solves your task.
• Validate behavior against existing tests before introducing new usage patterns.

Starter example

import { Argument } from "effect/unstable/cli";

const filename = Argument.string("filename");

Common pitfalls

• Unstable module contracts may change; avoid coupling core app logic directly to experimental details.
• Prefer explicit, typed combinators over ad-hoc casting or unchecked assumptions.

Not covered here

• Sibling facets under the same parent are out of scope:
  • effect-facet-unstable-cli-clierror (effect/unstable/cli/CliError)
  • effect-facet-unstable-cli-clioutput (effect/unstable/cli/CliOutput)
  • effect-facet-unstable-cli-command (effect/unstable/cli/Command)
  • effect-facet-unstable-cli-flag (effect/unstable/cli/Flag)
  • effect-facet-unstable-cli-helpdoc (effect/unstable/cli/HelpDoc)
  • effect-facet-unstable-cli-param (effect/unstable/cli/Param)
  • effect-facet-unstable-cli-primitive (effect/unstable/cli/Primitive)
  • effect-facet-unstable-cli-prompt (effect/unstable/cli/Prompt)
• Parent module ownership belongs to effect-module-unstable-cli.

Escalate to

• effect-module-unstable-cli for parent module-wide workflows.
• effect-skill-router for cross-module routing and ownership checks.

Reference anchors

• Facet source: packages/effect/src/unstable/cli/Argument.ts
• Parent tests: packages/effect/test/unstable/cli/Arguments.test.ts
• Parent tests: packages/effect/test/unstable/cli/Command.test.ts
• Parent tests: packages/effect/test/unstable/cli/completions/CommandDescriptor.test.ts
• Parent tests: packages/effect/test/unstable/cli/completions/completions.test.ts
• Parent tests: packages/effect/test/unstable/cli/Errors.test.ts
• Parent tests: packages/effect/test/unstable/cli/Help.test.ts
• API details: references/api-reference.md
• Usage notes: references/usage-reference.md
• Ownership mapping: references/owner.md