MPS Language Analysis

Workflow for inspecting an MPS language from a name (e.g. jetbrains.mps.lang.core). Returns concepts, metadata, structural info, and pointers to declarations and sample nodes.

Critical Directives

• Use the fully qualified language name (e.g. jetbrains.mps.lang.core) — single-letter shorthand (j.m.l.core) requires resolution first via mps_mcp_get_project_structure.
• For the qualifiedName returned by mps_mcp_get_concept_details, use it as the concept field in JSON blueprints. It is unambiguous.

Analyzing a Language by Name

1. Verify Language: call mps_mcp_get_project_structure with the language name as a filter (startingPoint: My_Language). This confirms existence and provides the UUID.
2. Retrieve Concepts: use mps_mcp_get_concept_details with the language name in languageRefs. Both conceptRefs and languageRefs accept either one value or a JSON-array string; omit the unused selector.
3. Extract Data: the response includes:
   • Name: concept FQN.
   • Description: found in shortDescription.
   • Metadata: isRootable, isAbstract, and the conceptReference ID.
   • Structure: properties, children, and references are detailed here.
4. Drill Down:
   • Declaration: use the sourceNode reference with mps_mcp_open_node to open the definition.
   • Examples: use mps_mcp_query_nodes with FIND_INSTANCES (sampleOnly: true) to get a sample node. Then use mps_mcp_print_node to see its canonical JSON structure for use as a template.
   • Inheritance: load the mps-language-inheritance skill for deeper hierarchy analysis.

Inspecting Concept Aspects

Use mps_mcp_query_structure with LIST_CONCEPT_ASPECTS to find associated definitions (Editor, Constraints, Behavior):

• Direct Aspects: returns roots targeting the specific concept.
• Inherited Aspects: set includeInherited: true to include aspects from ancestors (superconcepts/interfaces).
• Editor Analysis:
  • ConceptEditorDeclaration: defines the full editor for the targetsConcept.
  • EditorComponentDeclaration: defines reusable presentation pieces.
  • Check the editor model in the response to identify available editors.

Related Skills

• mps-language-inheritance — load when you need extended-language / superconcept / subconcept analysis.
• mps-aspect-structure-concepts — load when defining or modifying concepts (not just reading them).
• mps-language-aspects-overview — overview of which aspects exist and what each owns.

Reference Index

• Open references/search-concepts.md for the mps_mcp_search_concepts matching algorithm — haystack composition, subtoken splitting, fallback ranking, modelReference scoping, and the sub-2-char failure mode.
• Open references/concept-details.md for the mps_mcp_get_concept_details result schema and the unresolved-ref policy (all-failed vs partial-success envelopes and the suggestion heuristic).