Pointpointlanguage docs0.1.1

Reference

Effects

external, action, and policy blocks for interop, async IO, and pure guards.

Summary

Pure blocks (record, calculation, rule, label) stay free of IO. Effectful work uses external, action, and policy.

external

Declare npm or Node imports with typed signatures:

See examples/external.point and examples/action.point.

Externals are impure boundaries. Calculations should not call them directly.

action

Async operations with explicit effect metadata:

module Effects

external node fs
  read file(path: Text): Text from "node:fs" as readFileSync

action load config
  input path: Text
  output contents: Text
  touches file
  return read file(path)

touches values include network, file, env, process, time, random, database, or none. Action calls inside other actions or workflows require await (missing-await if omitted).

Database actions declare touches database so point index and review tools see the IO boundary. Use parameterized queries only — see Database interop.

policy and guard

Pure boolean guards:

See examples/policy.point.

Forms: allow expr, deny expr, require expr.

`guard output paths` scopes file writes in pipelines — see examples/pipelines/guarded-output.point.

Compiler note

  • external — import boundary with typed signature
  • action — async IO with touches metadata
  • policy / guard — pure boolean checks (pipeline guards scope file paths)

Examples

  • examples/external.point — externals
  • examples/action.point — file touch
  • examples/async.point — await
  • examples/policy.point — policies
  • examples/app/notes/notes.point — database actions

Common mistakes

  • Calling an action without await inside another action
  • Returning Error where a non-result type is expected

Agent diagnostic notes

  • Action refs in point index include effects metadata for review
  • Prefer patching .point when fixing effect boundaries

See also