```
## ---------------------------------------------------------------------
## A. SIMPLE EXAMPLES
## ---------------------------------------------------------------------
y <- c(16L, -3L, -2L, 15L, 15L, 0L, 8L, 15L, -2L)
selfmatch(y)
x <- c(unique(y), 999L)
findMatches(x, y)
countMatches(x, y)
## See ?`Ranges-comparison` for more examples (on Ranges objects). You
## might need to load the IRanges package first.
## ---------------------------------------------------------------------
## B. FOR DEVELOPERS: HOW TO IMPLEMENT THE BINARY COMPARISON OPERATORS
## FOR YOUR Vector SUBCLASS
## ---------------------------------------------------------------------
## The answer is: don't implement them. Just implement pcompare() and the
## binary comparison operators will work out-of-the-box. Here is an
## example:
## (1) Implement a simple Vector subclass.
setClass("Raw", contains="Vector", representation(data="raw"))
setMethod("length", "Raw", function(x) length(x@data))
setMethod("[", "Raw",
function(x, i, j, ..., drop) { x@data <- x@data[i]; x }
)
x <- new("Raw", data=charToRaw("AB.x0a-BAA+C"))
stopifnot(identical(length(x), 12L))
stopifnot(identical(x[7:3], new("Raw", data=charToRaw("-a0x."))))
## (2) Implement a "pcompare" method for Raw objects.
setMethod("pcompare", c("Raw", "Raw"),
function(x, y) {as.integer(x@data) - as.integer(y@data)}
)
stopifnot(identical(which(x == x[1]), c(1L, 9L, 10L)))
stopifnot(identical(x[x < x[5]], new("Raw", data=charToRaw(".-+"))))
```

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