message: [expr] convenience function for constants
diff: @@ -2104,7 +2104,12 @@ pub mod constraints {
  /// An alias for the intended usage of the expression type in constructing constraints.
  pub type E<F> = Expr<ConstantExpr<F>>;
  -/// Handy function to quickly create an expression for a witness.
  +/// Convenience function to create a constant as [Expr].
  +pub fn constant<F>(x: F) -> E<F> {
  + Expr::Constant(ConstantExpr::Literal(x))
  +}
  +
  +/// Helper function to quickly create an expression for a witness.
  pub fn witness<F>(i: usize, row: CurrOrNext) -> E<F> {
  E::<F>::cell(Column::Witness(i), row)
  }
  