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R consistent integer division and modulo operation #250

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R consistent integer division and modulo operation #250

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2 changes: 2 additions & 0 deletions NEWS.md
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,8 @@

1. `as.integer64.integer64` returns a plain `integer64` vector stripped of any attributes. This is consistent with R like behavior, e.g. `as.integer.integer`.

1. `%/%` does not truncate towards zero any more. It now matches R behavior of truncating towards negative infinity. For example, `as.integer64(-10L) %/% as.integer64(7L)` now gives `-2L`, not `-1L`. This is consistent with `-10L %/% 7L` in base R. Consequently, `%%` is also affected, e.g. `as.integer64(-10L) %% as.integer64(7L)` now gives `4L`, not `-3L`, consistent with `-10L %% 7L` in base R.

## NEW FEATURES

1. `anyNA` gets an `integer64` method. Thanks @hcirellu.
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9 changes: 8 additions & 1 deletion src/integer64.h
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Expand Up @@ -165,6 +165,7 @@ else { \
naflag = TRUE; \
}

/* int division truncate to lower */
#define INTDIV64(e1,e2,ret,naflag) \
if (e1 == NA_INTEGER64 || e2 == NA_INTEGER64) \
ret = NA_INTEGER64; \
Expand All @@ -175,8 +176,11 @@ else { \
ret = e1 / e2; \
if (ret == NA_INTEGER64) \
naflag = TRUE; \
else if (ret < 0 && ret*e2 != e1) \
ret -= 1; \
}

/* int division truncate to lower */
#define MOD64(e1,e2,ret,naflag) \
if (e1 == NA_INTEGER64 || e2 == NA_INTEGER64) \
ret = NA_INTEGER64; \
Expand All @@ -187,8 +191,11 @@ else { \
ret = e1 / e2; \
if (ret == NA_INTEGER64) \
naflag = TRUE; \
else \
else { \
if (ret < 0 && ret*e2 != e1) \
ret -= 1; \
ret = e1 - e2 * ret; \
} \
}

#define MIN64(e1,e2,ret) \
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10 changes: 9 additions & 1 deletion tests/testthat/test-integer64.R
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Expand Up @@ -253,7 +253,15 @@ test_that("arithmetic & basic math works", {

expect_identical(x %/% 2L, as.integer64(c(0L, 1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 5L)))
expect_identical(x %% 2L, as.integer64(rep_len(c(1L, 0L), 10L)))


x32 = c(10L, 10L, -10L, -10L, 10L, -10L)
y32 = c(3L, -3L, 3L, -3L, 0L, 0L)
x64 = as.integer64(x32)
y64 = as.integer64(y32)
expect_warning(expect_identical(as.integer64(x32) %/% as.integer64(y32), as.integer64(x32 %/% y32)), "NAs produced due to division by zero")
expect_warning(expect_identical(as.integer64(x32) %% as.integer64(y32), as.integer64(x32 %% y32)), "NAs produced due to division by zero")
expect_identical(suppressWarnings((x64%/%y64)*y64 + x64%%y64 == x64), c(rep(TRUE, 4L), rep(NA, 2L)))

expect_identical(sign(x - 6L), as.integer64(rep(c(-1L, 0L, 1L), c(5L, 1L, 4L))))
expect_identical(abs(x - 6.0), as.integer64(c(5:0, 1:4)))

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