Exploration of a possible DSL for user-readable Query Graph Model (QGM) instances.

qgm.dsl

Model {
  box B1 = Get {
    id: GlobalId::User(0),
    unique_keys: [[0], [1]],
    columns: [
      base(0): INT NOT NULL,
      base(1): INT NOT NULL,
      base(2): INT NOT NULL,
    ]
  }
  box B2 = Get {
    id: GlobalId::User(1),
    unique_keys: [[0]],
    columns: [
      base(0): INT NOT NULL,
      base(1): INT NOT NULL,
      base(2): INT NOT NULL,
    ]
  }
  box B3 = Select {
    quantifier x = Foreach(B1)
    quantifier y = Foreach(B2)
    quantifier z = Exists({
      let B4 = Select {
        quantifier u = Foreach(B1);
        quantifier v = Foreach(B2);
        if u#2 = v#0;
        if u#2 = x#2;
        columns: [
          base(0): INT NOT NULL,
          base(1): INT NOT NULL,
          base(2): INT NOT NULL,
        ]
      }
      let B5 = GroupBy {
        quantifier x = Foreach(B4)
        key: [x#0, x#1]
      }
      Select {
        quantifier x = Foreach(B4)
        key: [x#0, x#1]
      }
    })
    if rhs#2 = lhs#0
    if z > 0
  }
}