stream-infix: Infix stream operators

In thk686/pipestreamr: Non-blocking IO over stdin, stdout and stderr

Description

Infix stream operators

Usage

lhs %<<% rhs

lhs %<<.% rhs

lhs %>>% rhs

lhs %<>% rhs

lhs %<.>% rhs

Arguments

lhs	a pstream object
rhs	a data value or name

Details

The %<<% operator writes the object on the right-hand side to the pstream object on the left-hand side using write_stdin. The %>>% operator reads from the pstream object on the left-hand side and stores the result in the variable on the right-hand side using read_stdout. The %<>% operator writes a string to the stream and immediately reads from standard output and returns the result. This is mostly for quickly viewing the output from a program. The %<<.% and %<.>% operators write to standard input exactly as %<<% and %<>%, but also send end-of-file. This is necessary for some programs to process input.

Value

a pstream object invisibly

Examples

x = pstream("R", "--vanilla --slave")
x %<<% "R.Version()[[1]]"
x %>>% y
show(y)
x %<<% "R.Version()[[1]]" %<<% "dir()" %>>% y
show(y)
x %<>% "R.Version()[[1]]"
close(x)

x = pstream("tr", c("[:upper:]", "[:lower:]"))
x %<<.% "TEST1" %>>% y
show(y)

thk686/pipestreamr documentation built on May 31, 2019, 10:43 a.m.