RosettaCodeData/Task/Balanced-brackets/Red/balanced-brackets.red

; Functional code
balanced-brackets: [#"[" any balanced-brackets #"]"]
rule: [any balanced-brackets end]
balanced?: func [str][parse str rule]

; Tests
tests: [
    good: ["" "[]" "[][]" "[[]]" "[[][]]" "[[[[[]]][][[]]]]"]
    bad:  ["[" "]" "][" "[[]" "[]]" "[]][[]" "[[[[[[]]]]]]]"]
]

foreach str tests/good [
    if not balanced? str [print [mold str "failed!"]]
]
foreach str tests/bad [
    if balanced? str [print [mold str "failed!"]]
]

repeat i 10 [
    str: random copy/part "[][][][][][][][][][]" i * 2
    print [mold str "is" either balanced? str ["balanced"]["unbalanced"]]
]