github.com/joomcode/cue@v0.4.4-0.20221111115225-539fe3512047/cue/testdata/cycle/issue429.txtar

TODO: a bound value resolving to a disjunction should probably
be an error. In this case #Size.amx should resolve.

-- in.cue --
// Range disjunction without cycle (checks only one-way).
#Size: {
	res: uint | *0
	min: >res | *(1 + res)
	max: >min | *min
}

s0: #Size & {res: 1}
// This discards the default for max. This is correct, but unfortunate.
// TODO: is there a tweak to the default mechanism possible that would fix that?
//       Tread very carefully, though! Perhaps we could have a builtin that
//       discards any default, so that we can at least manually override this
//       behavior.
s1: #Size & {min: 5}
s2: #Size & {max: 5}
s3: #Size & {
	min: 5
	max: 10
}
es3: #Size & {
	min: 10
	max: 5
}

// Disjunctions with cycles
// TODO: improve error message here. Logic is correct, though.
#nonEmptyRange: {
	min: *1 | int
	min: <max
	max: >min
}
r1: #nonEmptyRange & {
	min: 3
}
r2: #nonEmptyRange & {
	max: 5
}
r3: #nonEmptyRange & {
	min: 3
	max: 6
}

er3: #nonEmptyRange & {
	min: 5
	max: 5
}
-- out/eval --
Errors:
er3.min: 2 errors in empty disjunction:
er3.min: conflicting values 1 and 5:
    ./in.cue:28:8
    ./in.cue:43:6
    ./in.cue:44:7
es3.max: 3 errors in empty disjunction:
es3.max: conflicting values 1 and 5:
    ./in.cue:4:16
    ./in.cue:5:15
    ./in.cue:20:6
    ./in.cue:22:7
es3.max: conflicting values 10 and 5:
    ./in.cue:5:15
    ./in.cue:20:6
    ./in.cue:21:7
    ./in.cue:22:7
es3.max: invalid value 5 (out of bound >10):
    ./in.cue:5:7
    ./in.cue:22:7
er3.max: invalid value 5 (out of bound >5):
    ./in.cue:30:7
    ./in.cue:45:7

Result:
(_|_){
  // [eval]
  #Size: (#struct){
    res: (int){ |(*(int){ 0 }, (int){ &(>=0, int) }) }
    min: (number){ |(*(int){ 1 }, (number){ >0 }) }
    max: (number){ |(*(int){ 1 }, (number){ >0 }, (number){ >1 }) }
  }
  s0: (#struct){
    res: (int){ 1 }
    min: (number){ |(*(int){ 2 }, (number){ >1 }) }
    max: (number){ |(*(int){ 2 }, (number){ >1 }, (number){ >2 }) }
  }
  s1: (#struct){
    res: (int){ |(*(int){ 0 }, (int){ &(>=0, int) }) }
    min: (int){ 5 }
    max: (number){ |(*(int){ 5 }, (number){ >5 }) }
  }
  s2: (#struct){
    res: (int){ |(*(int){ 0 }, (int){ &(>=0, int) }) }
    min: (number){ |(*(int){ 1 }, (number){ >0 }) }
    max: (int){ 5 }
  }
  s3: (#struct){
    res: (int){ |(*(int){ 0 }, (int){ &(>=0, int) }) }
    min: (int){ 5 }
    max: (int){ 10 }
  }
  es3: (_|_){
    // [eval]
    res: (int){ |(*(int){ 0 }, (int){ &(>=0, int) }) }
    min: (int){ 10 }
    max: (_|_){
      // [eval] es3.max: 3 errors in empty disjunction:
      // es3.max: conflicting values 1 and 5:
      //     ./in.cue:4:16
      //     ./in.cue:5:15
      //     ./in.cue:20:6
      //     ./in.cue:22:7
      // es3.max: conflicting values 10 and 5:
      //     ./in.cue:5:15
      //     ./in.cue:20:6
      //     ./in.cue:21:7
      //     ./in.cue:22:7
      // es3.max: invalid value 5 (out of bound >10):
      //     ./in.cue:5:7
      //     ./in.cue:22:7
    }
  }
  #nonEmptyRange: (#struct){
    min: (_|_){
      // [incomplete] #nonEmptyRange.min: incomplete cause disjunction
    }
    max: (_|_){
      // [incomplete] #nonEmptyRange.min: incomplete cause disjunction
    }
  }
  r1: (#struct){
    min: (int){ 3 }
    max: (number){ >3 }
  }
  r2: (#struct){
    min: (int){ |(*(int){ 1 }, (int){ &(<5, int) }) }
    max: (int){ 5 }
  }
  r3: (#struct){
    min: (int){ 3 }
    max: (int){ 6 }
  }
  er3: (_|_){
    // [eval]
    min: (_|_){
      // [eval] er3.min: 2 errors in empty disjunction:
      // er3.min: conflicting values 1 and 5:
      //     ./in.cue:28:8
      //     ./in.cue:43:6
      //     ./in.cue:44:7
      // er3.max: invalid value 5 (out of bound >5):
      //     ./in.cue:30:7
      //     ./in.cue:45:7
    }
    max: (_|_){
      // [eval] er3.max: invalid value 5 (out of bound >5):
      //     ./in.cue:30:7
      //     ./in.cue:45:7
    }
  }
}
-- out/compile --
--- in.cue
{
  #Size: {
    res: (&(int, >=0)|*0)
    min: (>〈0;res〉|*(1 + 〈0;res〉))
    max: (>〈0;min〉|*〈0;min〉)
  }
  s0: (〈0;#Size〉 & {
    res: 1
  })
  s1: (〈0;#Size〉 & {
    min: 5
  })
  s2: (〈0;#Size〉 & {
    max: 5
  })
  s3: (〈0;#Size〉 & {
    min: 5
    max: 10
  })
  es3: (〈0;#Size〉 & {
    min: 10
    max: 5
  })
  #nonEmptyRange: {
    min: (*1|int)
    min: <〈0;max〉
    max: >〈0;min〉
  }
  r1: (〈0;#nonEmptyRange〉 & {
    min: 3
  })
  r2: (〈0;#nonEmptyRange〉 & {
    max: 5
  })
  r3: (〈0;#nonEmptyRange〉 & {
    min: 3
    max: 6
  })
  er3: (〈0;#nonEmptyRange〉 & {
    min: 5
    max: 5
  })
}