PuduLangEnvironment.Domain.Layers

type: module path: "@root/src/PuduLangEnvironment/Domain/Layers.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.6 depth_status: MEDIUM tags: [module, domain] aliases: [PuduLangEnvironment.Domain.Layers]

Purpose

Entries, which assignment is kept, the merge of layers, and the settled view.

Interface

Signatures

export type Entry = { key: Str, value: Str }

export type Settled = { values: Map[Str, Str], applied: Array[Str] }

export fn keep(known: &Map[Str, Str], key: Str, value: Str, overwrite: Bool) -> Map[Str, Str]

export fn merge(layers: &Array[Array[Entry]], overwrite: Bool) -> Map[Str, Str]

export fn settle(loaded: &Map[Str, Str], process: &Map[Str, Str], overwrite: Bool) -> Settled

Linkage

• Requires: std only.
• Consumed by: [[src/PuduLangEnvironment/Domain/Parser]], [[src/PuduLangEnvironment/Loader]], [[src/PuduLangEnvironment/Variables]].

Algorithm

1. keep stores a value when overwriting or when the key is new.
2. merge keeps every entry of every layer in order.
3. settle starts from the process map and stores each loaded value when overwriting or when the process value is unset or empty; applied lists the stored keys in sorted order.

Negative Logic (Prohibited Paths)

• Without overwriting, a non-empty process variable is never replaced.

Edge Cases

• Without overwriting, the first assignment of a key wins across files and within one.

Depth

DEPTH 0.6 (MEDIUM). Tested by test/PuduLangEnvironment/Domain/LayersTest.pudu; mutation-tested.

Grill Log

• Q: Why may a load replace an empty process variable even without overwriting? A: An empty variable is absent to every reader ([[src/PuduLangEnvironment/Variables]]), so keeping it would discard a value for nothing. _Rejected:_ "set" meaning present at all.

• Q: Why is applied not sorted explicitly? A: A Map answers its entries in key order, so the keys are stored sorted as they are met; a second sort could not change the answer, and mutation testing reported it as such. _Rejected:_ List.sortBy over the applied keys.

Referenced by

[[CHANGELOG]] · [[domain/Layer]] · [[src/PuduLangEnvironment/Domain/Parser]] · [[src/PuduLangEnvironment/Domain/_MOC]] · [[src/PuduLangEnvironment/Loader]] · [[src/PuduLangEnvironment/Variables]] · [[subsystems/Loading]]