usememos/memos · error

boolean literal required

Error message

boolean literal required

What it means

Thrown by expectBool in the filter renderer when a boolean-only construct (e.g. `pinned` comparisons or boolean flags) receives a literal that is not a Go bool. The parser accepted it as a literal node, but the type assertion lit.(bool) failed, so the filter cannot be rendered to SQL.

Source

Thrown at internal/filter/render.go:862

	return r.addArg(v)
}

func expectLiteral(expr ValueExpr) (any, error) {
	lit, ok := expr.(*LiteralValue)
	if !ok {
		return nil, errors.New("expression must be a literal")
	}
	return lit.Value, nil
}

func expectBool(expr ValueExpr) (bool, error) {
	lit, err := expectLiteral(expr)
	if err != nil {
		return false, err
	}
	value, ok := lit.(bool)
	if !ok {
		return false, errors.New("boolean literal required")
	}
	return value, nil
}

func expectNumericLiteral(expr ValueExpr) (int64, error) {
	lit, err := expectLiteral(expr)
	if err != nil {
		return 0, err
	}
	return toInt64(lit)
}

func toInt64(value any) (int64, error) {
	switch v := value.(type) {
	case int:
		return int64(v), nil
	case int32:
		return int64(v), nil

View on GitHub (pinned to 14d757ce1f)

Solutions

1. Use bare boolean literals: `pinned == true` not `pinned == "true"`
2. Fix the client code that stringifies booleans before building filter strings
3. Validate filter strings against the engine (CompileToStatement) before saving them

Example fix

// before
filter := `pinned == "true"`
// after
filter := `pinned == true`

// Ensure boolean positions get bare true/false, not quoted strings or numbers
var quotedBool = regexp.MustCompile(`==\s*"(?:true|false)"`)
func hasQuotedBoolean(filter string) bool { return quotedBool.MatchString(filter) }

func isBoolLiteral(v any) bool { _, ok := v.(bool); return ok }

// Wrap compile; map 'boolean literal required' to a user-facing message with the offending fragment
if _, err := engine.CompileToStatement(ctx, filter, opts); err != nil {
  if strings.Contains(err.Error(), "boolean literal required") {
    return errors.New("use bare true/false without quotes in the filter")
  }
  return err
}

When it happens

Trigger: Filters like `pinned == "true"`, `pinned == 1`, or `pinned in [true, "false"]` where the boolean position gets a string or numeric literal.

Common situations: Frontends or scripts serializing booleans as strings (JSON query params), users quoting boolean values out of habit, or porting filters from a dialect where truthy coercion exists.

Related errors

• filter expression is empty
• filter must evaluate to a boolean value
• invalid use of in operator
• text match expects exactly one argument
• tags membership requires string literal

AI-assisted analysis of usememos/memos@14d757ce1f (2026-08-15). Data as JSON: /api/errors/5450bd89cbb7e29f. Report an issue: GitHub.