parseFasta: function [data][
    result: #[]
    current: ø
    loop split.lines data 'line [
        if? `>` = first line [
            current: slice line 1 (size line)-1
            set result current ""
        ]
        else ->
            set result current (get result current)++line
    ]
    return result
]

text: {
    >Rosetta_Example_1
    THERECANBENOSPACE
    >Rosetta_Example_2
    THERECANBESEVERAL
    LINESBUTTHEYALLMUST
    BECONCATENATED
}

inspect.muted parseFasta text