cmd/root.go

@@ -46,7 +46,10 @@ Examples:
   dirmd -o ./docs ~/repos/myproject --proton-drive
 
   # Interactive TUI mode
-  dirmd --tui`,
+  dirmd --tui
+
+  # Pick specific files in vertical slices mode
+  dirmd -o ./docs ~/repos/myproject --vertical-slices --pick common/src/lib.rs --pick mssql-extractor/src/processor.rs`,
 		RunE: run,
 	}
 
@@ -67,6 +70,8 @@ Examples:
 	omitMd         bool
 	tuiMode        bool
 	instructions   bool
+	pickPaths      []string
+	smallTree      bool
 )
 
 func Execute() {
@@ -93,6 +98,8 @@ func init() {
 	rootCmd.Flags().BoolVar(&omitTest, "omit-test", false, "exclude test files (Go *_test.go, Java *Test.java) and strip #[cfg(test)] blocks from Rust")
 	rootCmd.Flags().BoolVar(&omitMd, "omit-md", false, "omit all .md files except README.md")
 	rootCmd.Flags().BoolVar(&instructions, "instructions", false, "include .dirmd instructions file if present in root")
+	rootCmd.Flags().StringArrayVar(&pickPaths, "pick", nil, "repeatable: relative path to file to include as pick (requires --vertical-slices)")
+	rootCmd.Flags().BoolVar(&smallTree, "small-tree", false, "use breadcrumb-only tree for picked files (default: full tree)")
 }
 
 func run(cmd *cobra.Command, args []string) error {
@@ -120,6 +127,10 @@ func run(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("--skip-frontend and --frontend-only are mutually exclusive")
 	}
 
+	if len(pickPaths) > 0 && !verticalSlices {
+		return fmt.Errorf("--pick requires --vertical-slices")
+	}
+
 	excludedExts := append(config.DefaultExts, extensions...)
 	if skipFrontend {
 		excludedExts = append(excludedExts, config.FrontendExts...)
@@ -141,6 +152,8 @@ func run(cmd *cobra.Command, args []string) error {
 		OmitTest:            omitTest,
 		OmitMd:              omitMd,
 		IncludeInstructions: instructions,
+		PickPaths:           pickPaths,
+		SmallTree:           smallTree,
 	}
 
 	if singleFile != "" {

internal/config/config.go

@@ -11,7 +11,7 @@ import (
 const (
 	DefaultMaxSize  = 512 * 1024
 	DefaultMaxDepth = 20
-	Version         = "0.1.0"
+	Version         = "0.1.4"
 )
 
 var DefaultIgnores = []string{
@@ -65,6 +65,8 @@ type Config struct {
 	OmitTest            bool
 	OmitMd              bool
 	IncludeInstructions bool
+	PickPaths           []string
+	SmallTree           bool
 }
 
 func PrintUsage() {
@@ -94,6 +96,8 @@ func Parse() (*Config, error) {
 		omitTest            bool
 		omitMd              bool
 		includeInstructions bool
+		pickPaths           stringSlice
+		smallTree           bool
 	)
 
 	flag.StringVar(&input, "i", "", "single file input (append mode only)")
@@ -113,6 +117,8 @@ func Parse() (*Config, error) {
 	flag.BoolVar(&omitTest, "omit-test", false, "exclude test files and strip #[cfg(test)] blocks")
 	flag.BoolVar(&omitMd, "omit-md", false, "omit all .md files except README.md")
 	flag.BoolVar(&includeInstructions, "instructions", false, "include .dirmd instructions file if present in root")
+	flag.Var(&pickPaths, "pick", "repeatable: relative path to file to include as pick (requires --vertical-slices)")
+	flag.BoolVar(&smallTree, "small-tree", false, "use breadcrumb-only tree for picked files (default: full tree)")
 
 	flag.Usage = PrintUsage
 	flag.Parse()
@@ -137,6 +143,9 @@ func Parse() (*Config, error) {
 	if skipFrontend && frontendOnly {
 		return nil, fmt.Errorf("--skip-frontend and --frontend-only are mutually exclusive")
 	}
+	if len(pickPaths) > 0 && !verticalSlices {
+		return nil, fmt.Errorf("--pick requires --vertical-slices")
+	}
 
 	excludedExts := append(DefaultExts, exts...)
 	if skipFrontend {
@@ -159,6 +168,8 @@ func Parse() (*Config, error) {
 		OmitTest:            omitTest,
 		OmitMd:              omitMd,
 		IncludeInstructions: includeInstructions,
+		PickPaths:           pickPaths,
+		SmallTree:           smallTree,
 	}
 
 	if input != "" {

internal/renderer/renderer.go

@@ -10,6 +10,7 @@ import (
 	"unicode/utf8"
 
 	"git.flo.fo/FLO/dirmd/internal/config"
+	"git.flo.fo/FLO/dirmd/internal/filter"
 	"git.flo.fo/FLO/dirmd/internal/git"
 	"git.flo.fo/FLO/dirmd/internal/instructions"
 	"git.flo.fo/FLO/dirmd/internal/tree"
@@ -150,7 +151,17 @@ func WriteSlices(result *walker.Result, outputDir, repoName string) ([]string, e
 	rootSlicePath := filepath.Join(outputDir, rootSliceBasename)
 	generated = append(generated, rootSlicePath)
 
-	if err := writeRootIndex(rootPath, absRoot, rootName, repoName, topLevelDirs, result.Commit, result.Instructions, treeRoot, result.Cfg); err != nil {
+	pickInfos := make([]PickInfo, 0)
+
+	if len(result.Cfg.PickPaths) > 0 {
+		pickInfos, err = writePickFiles(absRoot, absRoot, outputDir, result.Cfg, result.OmitTest, result.Commit, treeRoot, result.Cfg.SmallTree)
+		if err != nil {
+			return nil, fmt.Errorf("failed to write pick files: %w", err)
+		}
+		generated = append(generated, pickInfoPaths(pickInfos)...)
+	}
+
+	if err := writeRootIndex(rootPath, absRoot, rootName, repoName, topLevelDirs, result.Commit, result.Instructions, treeRoot, result.Cfg, pickInfos); err != nil {
 		return nil, fmt.Errorf("failed to write root index: %w", err)
 	}
 
@@ -178,7 +189,137 @@ func WriteSlices(result *walker.Result, outputDir, repoName string) ([]string, e
 	return generated, nil
 }
 
-func writeRootIndex(path, absRoot, rootName, repoName string, topLevelDirs map[string][]walker.Entry, commit *git.CommitInfo, instContent string, treeRoot *tree.Node, cfg *config.Config) error {
+type PickInfo struct {
+	RelPath  string
+	FileType string
+	SliceDir string
+}
+
+func pickInfoPaths(picks []PickInfo) []string {
+	var paths []string
+	for _, p := range picks {
+		paths = append(paths, filepath.Join(p.SliceDir, p.FileType))
+	}
+	return paths
+}
+
+func writePickFiles(absRoot, baseRoot, outputDir string, cfg *config.Config, omitTest bool, commit *git.CommitInfo, treeRoot *tree.Node, smallTree bool) ([]PickInfo, error) {
+	var pickInfos []PickInfo
+
+	for _, pickPath := range cfg.PickPaths {
+		fullPath := filepath.Join(absRoot, pickPath)
+
+		info, err := os.Stat(fullPath)
+		if err != nil {
+			return nil, fmt.Errorf("cannot access pick path %s: %w", pickPath, err)
+		}
+
+		if info.IsDir() {
+			return nil, fmt.Errorf("pick path must be a file: %s", pickPath)
+		}
+
+		// Validate file passes filters
+		name := filepath.Base(pickPath)
+		filter := &filter.Filter{
+			MaxSize:      cfg.MaxSize,
+			Extensions:   cfg.Extensions,
+			Ignores:      cfg.Ignores,
+			OmitTest:     cfg.OmitTest,
+			FrontendOnly: cfg.FrontendOnly,
+			OmitMd:       cfg.OmitMd,
+		}
+
+		if filter.ShouldSkipFile(fullPath, name, info) {
+			return nil, fmt.Errorf("pick path %s filtered by active rules", pickPath)
+		}
+
+		// Determine slice dir from first path segment
+		parts := strings.Split(pickPath, string(filepath.Separator))
+		sliceDir := outputDir
+		if len(parts) > 1 {
+			sliceDir = filepath.Join(outputDir, parts[0])
+			if err := os.MkdirAll(sliceDir, 0755); err != nil {
+				return nil, fmt.Errorf("cannot create pick slice directory %s: %w", sliceDir, err)
+			}
+		} else {
+			// Root-level pick
+			sliceDir = outputDir
+		}
+
+		sliceName := filepath.Base(pickPath) + ".md"
+		pickPathOut := filepath.Join(sliceDir, sliceName)
+
+		if err := writePickFile(pickPathOut, absRoot, pickPath, omitTest, commit, cfg, treeRoot, smallTree); err != nil {
+			return nil, fmt.Errorf("failed to write pick %s: %w", pickPath, err)
+		}
+
+		pickInfos = append(pickInfos, PickInfo{
+			RelPath:  pickPath,
+			FileType: sliceName,
+			SliceDir: filepath.Base(sliceDir),
+		})
+	}
+
+	return pickInfos, nil
+}
+
+func writePickFile(path, absRoot, relPath string, omitTest bool, commit *git.CommitInfo, cfg *config.Config, treeRoot *tree.Node, smallTree bool) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("cannot create pick file: %w", err)
+	}
+	defer f.Close()
+
+	var sb strings.Builder
+
+	fmt.Fprintf(&sb, "# %s [SLICE]\n", filepath.Join(absRoot, relPath))
+	fmt.Fprintf(&sb, "> Generated: %s\n", time.Now().Format(time.RFC3339))
+	sb.WriteString(git.FormatCommitLine(commit))
+	sb.WriteString(FormatFlags(cfg))
+
+	fullPath := filepath.Join(absRoot, relPath)
+	content, err := readFileForOutput(fullPath, omitTest)
+	if err != nil {
+		return fmt.Errorf("cannot read pick file %s: %w", relPath, err)
+	}
+	language := extToLang(filepath.Ext(relPath))
+	lines := countLines(content)
+
+	if smallTree {
+		breadcrumb := tree.RenderBreadcrumb(absRoot, relPath)
+		fmt.Fprintf(&sb, "Tree: %s\n\n", breadcrumb)
+	} else {
+		sb.WriteString("## Directory Tree\n\n")
+		sb.WriteString(fenceChars + "\n")
+		sb.WriteString(renderTreeWithLegend(treeRoot, filepath.Base(absRoot)))
+		sb.WriteString(fenceChars + "\n\n")
+	}
+
+	fmt.Fprintf(&sb, "--- FILE: ./%s (%d bytes, %d lines) ---\n", relPath, infoSize(fullPath), lines)
+	sb.WriteString(fenceChars)
+	if language != "" {
+		sb.WriteString(language)
+	}
+	sb.WriteString("\n")
+	sb.WriteString(content)
+	if !strings.HasSuffix(content, "\n") {
+		sb.WriteString("\n")
+	}
+	sb.WriteString(fmt.Sprintf("%s\n--- END FILE ---\n\n", fenceChars))
+
+	_, err = f.WriteString(sb.String())
+	return err
+}
+
+func infoSize(path string) int64 {
+	info, err := os.Stat(path)
+	if err != nil {
+		return 0
+	}
+	return info.Size()
+}
+
+func writeRootIndex(path, absRoot, rootName, repoName string, topLevelDirs map[string][]walker.Entry, commit *git.CommitInfo, instContent string, treeRoot *tree.Node, cfg *config.Config, picks []PickInfo) error {
 	f, err := os.Create(path)
 	if err != nil {
 		return fmt.Errorf("cannot create root index: %w", err)
@@ -207,11 +348,9 @@ func writeRootIndex(path, absRoot, rootName, repoName string, topLevelDirs map[s
 	sb.WriteString("| Slice File | Directory | Files | Total Bytes |\n")
 	sb.WriteString("|------------|-----------|-------|-------------|\n")
 
-	// First row: root slice
 	rootSliceFile := "root_" + repoName + ".md"
-	rootFileCount := 0
+	rootFileCount := len(topLevelDirs)
 	rootTotalBytes := int64(0)
-	// We'll calculate this in the caller, for now placeholder
 	fmt.Fprintf(&sb, "| %s | (root) | %d | %d |\n", rootSliceFile, rootFileCount, rootTotalBytes)
 
 	for _, dirName := range sortedKeys(topLevelDirs) {
@@ -226,6 +365,15 @@ func writeRootIndex(path, absRoot, rootName, repoName string, topLevelDirs map[s
 	}
 	sb.WriteString("\n")
 
+	if len(picks) > 0 {
+		sb.WriteString("## Picks\n\n")
+		sb.WriteString("These files were explicitly selected via --pick flags.\n\n")
+		for _, p := range picks {
+			fmt.Fprintf(&sb, "- `%s` (%s)\n", p.RelPath, p.SliceDir)
+		}
+		sb.WriteString("\n")
+	}
+
 	_, err = f.WriteString(sb.String())
 	return err
 }

internal/tree/unfiltered.go

@@ -168,3 +168,22 @@ var frontendExts = []string{
 	".ts", ".tsx",
 	".vue", ".svelte",
 }
+
+func RenderBreadcrumb(absRoot, relPath string) string {
+	var sb strings.Builder
+	rootName := filepath.Base(absRoot)
+	dir := filepath.Dir(relPath)
+	if dir == "." {
+		return rootName + "/" + filepath.Base(relPath)
+	}
+
+	parts := strings.Split(filepath.ToSlash(dir), "/")
+	sb.WriteString(rootName)
+	for _, part := range parts {
+		sb.WriteString(" / ")
+		sb.WriteString(part)
+	}
+	sb.WriteString(" / ")
+	sb.WriteString(filepath.Base(relPath))
+	return sb.String()
+}