mal/chuck/step1_read_print.ck

// @import readline.ck
// @import types/boxed/*.ck
// @import types/MalObject.ck
// @import types/mal/MalAtom.ck
// @import types/mal/MalError.ck
// @import types/mal/MalNil.ck
// @import types/mal/MalFalse.ck
// @import types/mal/MalTrue.ck
// @import types/mal/MalInt.ck
// @import types/mal/MalString.ck
// @import types/mal/MalSymbol.ck
// @import types/mal/MalKeyword.ck
// @import types/mal/MalList.ck
// @import types/mal/MalVector.ck
// @import types/mal/MalHashMap.ck
// @import util/*.ck
// @import reader.ck
// @import printer.ck

fun MalObject READ(string input)
{
    return Reader.read_str(input);
}

fun MalObject EVAL(MalObject m)
{
    return m;
}

fun string PRINT(MalObject m)
{
    return Printer.pr_str(m, true);
}

fun string errorMessage(MalObject m)
{
    (m$MalError).value() @=> MalObject value;

    if( value.type == "string" )
    {
        return Printer.pr_str(value, false);
    }
    else
    {
        return "exception: " + Printer.pr_str(value, true);
    }
}

fun string rep(string input)
{
    READ(input) @=> MalObject m;

    if( m.type == "error" )
    {
        return errorMessage(m);
    }
    else
    {
        return PRINT(EVAL(m));
    }
}

fun void main()
{
    int done;

    while( !done )
    {
        Readline.readline("user> ") => string input;

        if( input != null )
        {
            rep(input) => string output;

            if( output == "empty input" )
            {
                // proceed immediately with prompt
            }
            else
            {
                Util.println(output);
            }
        }
        else
        {
            true => done;
        }
    }
}

main();