Diagnostics · unsupported

unsupported[nonnumeric-comparison]

A string or boolean comparison not written as Entity.field op literal.

The fact comes first and the literal second. Two string facts cannot be compared: pass their relation as a boolean fact (see Patterns).

Example

Through compileSource
CONTRACT Claim {
  ENFORCEMENT_MODE: enforced
  CONTEXT {
    ENTITIES Request {
      count: int
      region: string
      ready: bool
      ratio: float
    }
    CONSTANTS {
      zero: int == 0 [SOURCE:POLICY]
      cap: int == 25 [SOURCE:POLICY]
    }
  }
  TRIGGER {
    grant()
  }
  GUARANTEE {
    ENSURE grant() WHEN Request.ready == true [SOURCE:must_be_ready]
  }
  PROHIBITION {
    FORBID grant WHEN "eu" == Request.region [SOURCE:region]
  }
}

rejected unsupported[nonnumeric-comparison] at 22:23 nonnumeric comparisons require a field and literal

Fix

Through compileSource
CONTRACT Claim {
  ENFORCEMENT_MODE: enforced
  CONTEXT {
    ENTITIES Request {
      count: int
      region: string
      ready: bool
      ratio: float
    }
    CONSTANTS {
      zero: int == 0 [SOURCE:POLICY]
      cap: int == 25 [SOURCE:POLICY]
    }
  }
  TRIGGER {
    grant()
  }
  GUARANTEE {
    ENSURE grant() WHEN Request.ready == true [SOURCE:must_be_ready]
  }
  PROHIBITION {
    FORBID grant WHEN Request.region == "eu" [SOURCE:region]
  }
}

accepted

See also: the specification.