haskell-do-match.js

var samples =
    [ '    do var <- readTVar'
    , 'do foo'
    , 'main =   do let x = do { foo }'
    , 'main = do let x = do foo'
    , 'main = foo $ do '
    ];

for (var i in samples) {
    var line = samples[i];
    if (line.search(/(\s*do\s+)/) !== -1) {
        var lastDo = line.lastIndexOf("do");
        var rest = line.substring(lastDo+2);
        if (rest.trim() === "") {
            console.log("No match: " + line);
            continue;
        }
        if (rest.indexOf("{") !== -1) {
            lastDo = line.substring(0, lastDo).lastIndexOf("do");
        }
        var ident = Array(lastDo+1+3).join(" ");
        console.log(line);
        console.log(ident + "^");
        console.log("--------------------------");
    } else {
        console.log("No match: " + line);
    }
}