src/answer.bend source

src/answer.bend on the hub · documented module

# src/answer: reading an answer, which is the exit status on its own first# line, then everything the program printed.import Base# one char of the status: a newline ends it, and any other char is part of it,# with the rest of the status read only thendef code.at(nl: Bool, +ch: Char, rest: Unit -> String) -> String:  match nl:    case True{}:      SNil{}    case False{}:      SCon{ch, rest(Unit{})}# the exit status a run answered with: the answer up to its first newline.# It reads no further, so a long body costs nothing.def code(out: String) -> String:  match out:    case SNil{}:      SNil{}    case SCon{+ch, tail}:      code.at(Char.is_eq(ch, '\n'), ch, _u => code(tail))# one char before the body: a newline starts the body, which is the rest as# it stands, and any other char is still the statusdef text.at(nl: Bool, +tail: String, rest: Unit -> String) -> String:  match nl:    case True{}:      tail    case False{}:      rest(Unit{})# what the program printed, stdout and stderr together: the answer after its# first newline, or nothing when it has none. The body is returned as it# stands, never walked.def text(out: String) -> String:  match out:    case SNil{}:      SNil{}    case SCon{ch, +tail}:      text.at(Char.is_eq(ch, '\n'), tail, _u => text(tail))# a run that finished with status 0def ok(+out: String) -> Bool:  String.eq(code(out), "0")