brain/sqlbrain: don't use nulls when forgetting

Author: zephyrtronium

brain/braintest/braintest.go

@@ -38,7 +38,8 @@ func testForgetful(ctx context.Context, br Interface) func(t *testing.T) {
 			Time: time.Unix(0, 0),
 		}
 		text := "bocchi ryou nijika kita"
-		if err := brain.Learn(ctx, br, &msg, brain.Tokens(nil, text)); err != nil {
+		toks := brain.Tokens(nil, text)
+		if err := brain.Learn(ctx, br, &msg, toks); err != nil {
 			t.Errorf("failed to learn: %v", err)
 		}
 		s, err := brain.Speak(ctx, br, tag, "")
@@ -48,14 +49,14 @@ func testForgetful(ctx context.Context, br Interface) func(t *testing.T) {
 		if s != text {
 			t.Errorf("surprise thought: %q", s)
 		}
-		if err := brain.Forget(ctx, br, tag, brain.Tokens(nil, text)); err != nil {
+		if err := brain.Forget(ctx, br, tag, toks); err != nil {
 			t.Errorf("failed to forget: %v", err)
 		}
 		// We don't really care about an error here, since the brain is empty.
 		// All we care about is no thoughts.
 		s, _ = brain.Speak(ctx, br, tag, "")
 		if s != "" {
-			t.Errorf("remembered that which must be forgotten: %v", err)
+			t.Errorf("remembered that which must be forgotten: %q", s)
 		}
 	}
 }

brain/sqlbrain/forget.go

@@ -22,7 +22,7 @@ import (
 func (br *Brain) Forget(ctx context.Context, tag string, tuples []brain.Tuple) error {
 	names := make([]sq.NamedArg, 2+br.order)
 	names[0] = sql.Named("tag", tag)
-	terms := make([]sq.NullString, 1+br.order)
+	terms := make([]string, 1+br.order)
 	for i := 0; i < br.order; i++ {
 		names[i+1] = sql.Named("p"+strconv.Itoa(i), &terms[i])
 	}
@@ -40,10 +40,8 @@ func (br *Brain) Forget(ctx context.Context, tag string, tuples []brain.Tuple) e
 		// Note that each p[i] is a named arg, and those for the prefix and
 		// suffix each point to an element of terms. So, updating terms is
 		// sufficient to update the query parameters.
-		for i, w := range tup.Prefix {
-			terms[i] = sq.NullString{String: w, Valid: w != ""}
-		}
-		terms[br.order] = sq.NullString{String: tup.Suffix, Valid: tup.Suffix != ""}
+		copy(terms, tup.Prefix)
+		terms[br.order] = tup.Suffix
 		// Execute the statements in order. We do this manually because the
 		// arguments differ for some statements, and the SQLite3 driver
 		// complains if we give the wrong ones.