问thinkscript if语句失败

EN

input price = close;
input smoothPeriods = 20;
def output = Average(price, smoothPeriods);
# Get the current offset from the right edge from BarNumber()
# BarNumber(): The current bar number. On a chart, we can see that the number increases
# from left 1 to number of bars e.g. 140 at the right edge.
def barNumber = BarNumber();
def barCount = HighestAll(barNumber);
# rightOffset: 0 at the right edge, i.e. at the rightmost bar,
# increasing from right to left.
def rightOffset = barCount - barNumber;

# Prepare a lookup table:
def lookup;
if (barNumber == 1) {
    lookup = -1;
} else {
    lookup = 53;
}

# This script gets the minimum value from data in the offset range between startIndex
# and endIndex. It serves as a functional but not direct replacement for the
# GetMinValueOffset function where a dynamic range is required. Expect it to be slow.
script getMinValueBetween {
    input data = low;
    input startIndex = 0;
    input endIndex = 0;
    plot minValue = fold index = startIndex to endIndex with minRunning = Double.POSITIVE_INFINITY do Min(GetValue(data, index), minRunning);
}

# Call this only once at the last bar.
script buildValue {
    input lookup = close;
    input offsetLast = 0;
# Do an indirect lookup
    def lookupPosn = 23;
    def indirectLookupPosn = GetValue(lookup, lookupPosn);
# lowAtIndirectLookupPosn is assigned incorrectly. The if statement APPEARS to be executed
# as if indirectLookupPosn was 0 but indirectLookupPosn is NOT 0 so the condition
# for the first branch should be met!
    def lowAtIndirectLookupPosn;
    if (indirectLookupPosn > offsetLast) {
        lowAtIndirectLookupPosn = getMinValueBetween(low, offsetLast, indirectLookupPosn);
    } else {
        lowAtIndirectLookupPosn = close[offsetLast];
    }
    plot testResult = lowAtIndirectLookupPosn;
}
plot debugLower;
if (rightOffset == 0) {
    debugLower = buildValue(lookup);
} else {
    debugLower = 0;
}
declare lower;

def output;

def rightOffset;

def lookup;