extend type Query {
  expr: Expr! @experimental(flagName: "univ-keys")
}

"""
Expr contains helpers for working with Expr expressions.
"""
type Expr {
  """
  exprToCondition converts an Expr expression to a Condition.
  """
  exprToCondition(input: ExprToConditionInput!): Condition!
    @goField(forceResolver: true)

  """
  conditionToExpr converts a Condition to an Expr expression.
  """
  conditionToExpr(input: ConditionToExprInput!): String!
    @goField(forceResolver: true)
}

"""
ExprExpression is a scalar type that represents an Expr expression.
"""
scalar ExprExpression

"""
ExprBooleanExpression is a scalar type that represents an Expr expression that evaluates to a boolean.
"""
scalar ExprBooleanExpression

"""
ExprStringExpression is a scalar type that represents an Expr expression that evaluates to a string.
"""
scalar ExprStringExpression

"""
ExprValue is a scalar type that represents an Expr value.
"""
scalar ExprValue

"""
ExprIdentifier is a scalar type that represents an Expr identifier.
"""
scalar ExprIdentifier

"""
ExprOperator is a scalar type that represents an Expr operator.
"""
scalar ExprOperator

input ExprToConditionInput {
  expr: ExprBooleanExpression!
}

type Condition {
  clauses: [Clause!]!
}

type Clause {
  field: ExprIdentifier!
  operator: ExprOperator!

  """
  Value is a constant value that the field should be compared against.
  """
  value: ExprValue!

  """
  Negate indicates whether the clause should be negated (e.g., not contains vs. contains).
  """
  negate: Boolean!
}

input ConditionToExprInput {
  condition: ConditionInput!
}

input ConditionInput {
  clauses: [ClauseInput!]!
}

input ClauseInput {
  field: ExprIdentifier!
  operator: ExprOperator!

  """
  Value is a constant value that the field should be compared against.
  """
  value: ExprValue!

  """
  Negate indicates whether the clause should be negated (e.g., not contains vs. contains).
  """
  negate: Boolean!
}