Calculate a SHA1 hash of an object. The main difference with
`digest(x, algo = "sha1")`

is that `sha1()`

will give the same hash on
32-bit and 64-bit systems. Note that the results depends on the setting of
`digits`

and `zapsmall`

when handling floating point numbers. The
current defaults keep `digits`

and `zapsmall`

as large as possible
while maintaining the same hash on 32 bit and 64 bit systems.

```
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for numeric
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for complex
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for Date
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for matrix
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for data.frame
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for array
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for list
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for pairlist
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for POSIXlt
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for POSIXct
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for anova
sha1(x, digits = 4, zapsmall = 7, ..., algo = "sha1")
# S3 method for function
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
```# S3 method for formula
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for `(`
sha1(...)

sha1_digest(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for NULL
sha1(...)
# S3 method for name
sha1(...)

sha1_attr_digest(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
# S3 method for call
sha1(...)
# S3 method for character
sha1(...)
# S3 method for factor
sha1(...)
# S3 method for integer
sha1(...)
# S3 method for logical
sha1(...)
# S3 method for raw
sha1(...)

x

the object to calculate the SHA1

digits

the approximate number of significant digits in base 10. Will
be converted to a base 16 equivalent. Defaults to `digits = 14`

, except for
sha1.anova where `digits = 4`

zapsmall

the approximate negative magnitude of the smallest relevant
digit. Will be converted to a base 2 equivalent. Values smaller than this
number are equivalent to 0. Defaults to `zapsmall = 7`

...

If it is the only defined argument, passed to another `sha1`

method. If other arguments exist, see Details for usage.

algo

The hashing algoritm to be used by `digest`

. Defaults to
"sha1"

`sha1_digest()`

is a convenience function for objects where attributes
cannot be added to apply the `digest()`

function to its arguments.
`sha1_attr_digest()`

is a convenience function for objects where objects
can be added to generate the hash. If generating hashes for objects in other
packages, one of these two functions is recommended for use (typically,
`sha1_attr_digest()`

).

Extra arguments:

environment: An optional extra argument for `sha1.function`

and
`sha1.formula`

should be TRUE, FALSE or missing. `sha1.function`

and
`sha1.formula`

will ignore the enviroment of the function only when
`environment = FALSE`

.