Function detectCircularModelAliases

pkg/workflow/model_alias_validation.go:241–277

─── V-MAF-010: circular alias detection ───────────────────────────────────── detectCircularModelAliases performs a full DFS cycle check over the merged alias map and returns an error naming every alias in the cycle (V-MAF-010). Algorithm (Section 8.6.1): For each alias key, perform a depth-first

(aliasMap map[string][]string, markdownPath string)

//	If any traversal reaches an alias key already on the current path, a cycle
//	is detected and MUST be reported as a compile-time error.
func detectCircularModelAliases(aliasMap map[string][]string, markdownPath string) error {
	modelAliasValidationLog.Printf("Checking for circular alias references in %d aliases", len(aliasMap))

	// visited tracks keys for which all DFS descendants have been fully explored
	// (no cycle detected from that key).
	visited := map[string]struct {
	}{}

	// Iterate keys in deterministic order for reproducible error messages.
	keys := sliceutil.SortedKeys(aliasMap)

	state := &dfsState{
		aliasMap: aliasMap,
		visited:  visited,
		onPath:   make(map[string]bool, 16),
		path:     make([]string, 0, 16),
	}

	for _, key := range keys {
		if setutil.Contains(visited, key) {
			continue
		}
		clear(state.onPath)
		state.path = state.path[:0]
		if cycle := state.dfs(key); cycle != nil {
			// Format cycle chain for a clear error message.
			chain := strings.Join(append(cycle, cycle[0]), " → ")
			return formatCompilerError(markdownPath, "error",
				fmt.Sprintf("circular alias reference detected: %s\n\n"+
					"Circular alias references are prohibited. Remove or rewrite the cycle in the 'models:' "+
					"frontmatter section (V-MAF-010).", chain),
				nil)
		}
	}

	return nil
}

// dfsState holds the mutable state for a single DFS traversal.
type dfsState struct {