module main

type SecondTokenizerValue = []rune | Keyword

enum AdvancedTokenType {
    identifier
    keyword
    newline
}

struct SecondTokenizerToken {
    type  AdvancedTokenType
    value ?SecondTokenizerValue
}

enum Keyword {
    module
    import
}

fn test_main() {
    mut tokens := []SecondTokenizerToken{}
    tokens << SecondTokenizerToken{
        type:  AdvancedTokenType.keyword
        value: Keyword.module
    }
    build_ast(tokens) or { assert err.msg() == 'Handling module' }
}

struct RootAST {
mut:
    module []rune
}

fn build_ast(tokens []SecondTokenizerToken) !RootAST {
    for _ in 0 .. 1 {
        token := tokens[0]
        match true {
            false {
                return error('Expected `module` keyword at the start of the file, but got `${token.type}`')
            }
            token.type == .keyword && token.value == ?SecondTokenizerValue(Keyword.module) {
                return error('Handling module')
            }
            else {
                continue
            }
        }
    }

    return error('Not implemented')
}