1 files changed, 43 insertions, 6 deletions

diff --git a/internal/engine/match.go b/internal/engine/match.go
index ffee7f0..8daea9d 100644
--- a/internal/engine/match.go
+++ b/internal/engine/match.go
@@ -34,6 +34,10 @@ type FileMatch struct {
 	Rules    []RuleMatch // matching rules in order, ending at the first with (stop)
 	Warnings []string    // "<rule>: <warning>", e.g. "acme: content unreadable: needs pdftotext, not installed"
 
+	// Excluded is the (exclude ...) form that set this file aside before any
+	// rule ran, as written; "" when none did. An excluded file has no Rules.
+	Excluded string
+
 	// NoDelete is non-empty when no delete step may run for this file (spec
 	// §5.5 rule 2), and says why: the file is a duplicate under a scope its
 	// directory's rules use, or that check failed. Only set for a file some
@@ -92,7 +96,7 @@ func (e *Engine) Match(ctx context.Context, d *Dir) (*Result, error) {
 
 	var matched, unmatched []FileMatch
 	for _, fm := range fileMatches {
-		if len(fm.Rules) > 0 {
+		if len(fm.Rules) > 0 || fm.Excluded != "" {
 			matched = append(matched, fm)
 		} else {
 			unmatched = append(unmatched, fm)
@@ -119,6 +123,16 @@ func (e *Engine) Match(ctx context.Context, d *Dir) (*Result, error) {
 func evalFile(run *matchRun, file scan.File) FileMatch {
 	f := newFacts(run, file)
 	fm := FileMatch{File: file}
+	for _, x := range run.d.Excludes {
+		res := x.Cond.Eval(f)
+		for _, w := range res.Warnings {
+			fm.Warnings = append(fm.Warnings, "exclude: "+w)
+		}
+		if res.Match {
+			fm.Excluded = x.Text
+			return fm
+		}
+	}
 	for _, r := range run.d.Rules {
 		res := r.Cond.Eval(f)
 		for _, w := range res.Warnings {
@@ -180,12 +194,21 @@ type RuleTrace struct {
 	Stopped string      // "stopped by rule acme" when an earlier (stop) ended the search
 }
 
+// ExcludeTrace is one (exclude ...) form's outcome in an Explain call.
+type ExcludeTrace struct {
+	Text  string
+	Match bool
+	Trace *cond.Trace
+}
+
 // Explanation is why (or why not) krino would act on one file.
 type Explanation struct {
-	Dir   *Dir
-	File  scan.File
-	Skip  string // why krino would not look at this file at all; "" when it would
-	Rules []RuleTrace
+	Dir      *Dir
+	File     scan.File
+	Skip     string // why krino would not look at this file at all; "" when it would
+	Excludes []ExcludeTrace
+	Excluded string // the first exclude that matches, which sets the file aside; "" when none does
+	Rules    []RuleTrace
 }
 
 // Explain reports, for one file, whether krino's ordinary scan would ever
@@ -235,6 +258,16 @@ func (e *Engine) Explain(ctx context.Context, path string) (*Explanation, error)
 	run := newMatchRun(e, d, ctx, now, e.filesForExplain(d, sf, excl, now))
 	f := newFacts(run, sf)
 
+	var excludes []ExcludeTrace
+	excluded := ""
+	for _, x := range d.Excludes {
+		trace := x.Cond.Explain(f)
+		excludes = append(excludes, ExcludeTrace{Text: x.Text, Match: trace.Value, Trace: trace})
+		if trace.Value && excluded == "" {
+			excluded = x.Text
+		}
+	}
+
 	var rules []RuleTrace
 	stoppedBy := ""
 	for _, r := range d.Rules {
@@ -253,7 +286,7 @@ func (e *Engine) Explain(ctx context.Context, path string) (*Explanation, error)
 		}
 	}
 
-	return &Explanation{Dir: d, File: sf, Skip: skip, Rules: rules}, nil
+	return &Explanation{Dir: d, File: sf, Skip: skip, Excludes: excludes, Excluded: excluded, Rules: rules}, nil
 }
 
 // filesForExplain returns the file set Explain's duplicate checks run
@@ -285,6 +318,7 @@ func walkOptions(d *Dir, excl []string, now time.Time) scan.Options {
 		Exclude:   excl,
 		Busy:      d.Settings.Busy,
 		MinAge:    d.Settings.MinAge,
+		MaxSize:   d.Settings.MaxSize,
 		Now:       now,
 	}
 }
@@ -328,6 +362,9 @@ func explainSkip(d *Dir, sf scan.File, excl []string, now time.Time) string {
 	if now.Sub(sf.ModTime) < d.Settings.MinAge {
 		return "too new"
 	}
+	if d.Settings.MaxSize > 0 && sf.Size > d.Settings.MaxSize {
+		return "too big"
+	}
 	return ""
 }