Capabilities

This page answers one question: “What can I do with DataSheetLang today?”
For exact YAML shapes, field lists, and command flags, use the linked reference pages.

Core idea

You write a spec describing create / update / delete operations. The CLI validates and applies those operations to your XML DataSheet in a repeatable, reviewable way.

Supported entities

Entity	Create	Update	Delete	Where it applies
Items	✅	✅	✅	ItemTemplate.xml
Equipment	✅	✅	✅	EquipmentTemplate.xml
ItemStrings	✅	✅	✅	StrSheet_Item.xml

See: Entities

Supported operations

• Create: add new entries by id
• Update: modify an existing entry by id (only the fields you declare)
• Delete: remove entries by id

See: Syntax

Productivity features

Presets and inheritance

• Reuse common patterns with presets
• Support single inheritance (extends) with validation (depth limits, no cycles)

See: Presets

Block presets for nested structures

For deeply nested blocks, block presets support deep-merge semantics so you can reuse shared nested configs without rewriting entire objects.

See: Presets

Inline blocks on items

Items can embed inline blocks that expand into related changes:

• equipment: inline block
• strings: inline block

See: Syntax and Entities

Patch sequencing

Specs can be applied in a defined order to support patch transitions over time (reviewable diffs, repeatable application).

See: CLI

Safety and determinism

• Specs are validated before execution (syntax, required fields, preset resolution, supported values)
• The same inputs produce the same changes (deterministic behavior)
• Failures return structured error codes to speed up debugging

What’s intentionally not supported (yet)

These are out of scope for the current phase:

• “where/filter” bulk updates (e.g., update every item matching a condition)
• User-facing rollback/undo
• Interactive REPL
• Arbitrary cross-entity relationship editing (beyond what inline blocks cover)