// Convert to PNG by
// dot -Tpng databases.dot -o databases.png

digraph {

rankdir = "TB";

{
  rank=same; ExpandDatabase; InternDatabase
}
{
  rank=same; HirDatabase; EqwalizerDatabase
}
{
  rank=same; SourceDatabase; LineIndexDatabase
}
{
  rank=max; FileLoader; "salsa::Database"
}

    // Inputs
    SourceDatabase    [label="SourceDatabase\nbase_db";    style=filled;]
    SourceDatabaseExt [label="SourceDatabaseExt\nbase_db"; style=filled;]

    // Using the erlang-based parser
    EqwalizerDatabase [label="EqwalizerDatabase\nide_db"; style=filled; color="brown1"]
    EqwalizerLoader   [label="EqwalizerLoader\nide_db";   style=filled; color="brown1"]
    ErlAstDatabase    [label="ErlAstDatabase\nide_db";    style=filled; color="brown1"]
    AstLoader         [label="AstLoader\nerl_ast";        style=filled; color="brown1"]

    // Main external API exposure
    HirDatabase       [label="HirDatabase\nhir"; style=filled; color="lightblue"]
    // Internal to HIR, but exposed via HirDatabase
    ExpandDatabase    [label="ExpandDatabase\nhir_expand"; style=filled; color="lightblue"]
    DefDatabase       [label="DefDatabase\nhir_def"; style=filled; color="lightblue"]

    InternDatabase    [label="InternDatabase\nhir_def"]

    // Utility and low level
    FileLoader        [label="FileLoader\nbase_db"]
    LineIndexDatabase [label="LineIndexDatabase\nide_db"]
    "salsa::Database"

    //------------------------------------------------------------------

    // pub trait SourceDatabase: FileLoader + salsa::Database {
    SourceDatabase -> FileLoader
    SourceDatabase -> "salsa::Database"

    // pub trait SourceDatabaseExt: SourceDatabase {
    SourceDatabaseExt -> SourceDatabase

    // pub trait EqwalizerDatabase: SourceDatabase + EqwalizerLoader + ErlAstDatabase {
    EqwalizerDatabase -> SourceDatabase
    EqwalizerDatabase -> EqwalizerLoader
    EqwalizerDatabase -> ErlAstDatabase

    // pub trait LineIndexDatabase: SourceDatabase {
    LineIndexDatabase -> SourceDatabase

    // pub trait ErlAstDatabase: SourceDatabase + AstLoader {
    ErlAstDatabase -> SourceDatabase
    ErlAstDatabase -> AstLoader

    // pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {}
    HirDatabase -> DefDatabase
    // HirDatabase -> "Upcast<dyn DefDatabase>"

    // pub trait ExpandDatabase: SourceDatabase {
    ExpandDatabase -> SourceDatabase

    // pub trait InternDatabase: SourceDatabase {
    InternDatabase -> SourceDatabase

    // pub trait DefDatabase: InternDatabase + ExpandDatabase + Upcast<dyn ExpandDatabase> {
    DefDatabase -> InternDatabase
    DefDatabase -> ExpandDatabase
    // DefDatabase -> "Upcast<dyn ExpandDatabase>"

}