local_bindings() temporarily changes bindings in .env (which
is by default the caller environment). The bindings are reset to
their original values when the current frame (or an arbitrary one
if you specify .frame) goes out of scope.
with_bindings() evaluates expr with temporary bindings. When
with_bindings() returns, bindings are reset to their original
values. It is a simple wrapper around local_bindings().
local_bindings(..., .env = .frame, .frame = caller_env())with_bindings(.expr, ..., .env = caller_env())
local_bindings() returns the values of old bindings
invisibly; with_bindings() returns the value of expr.
Pairs of names and values. These dots support splicing (with value semantics) and name unquoting.
An environment.
The frame environment that determines the scope of the temporary bindings. When that frame is popped from the call stack, bindings are switched back to their original values.
An expression to evaluate with temporary bindings.
foo <- "foo"
bar <- "bar"
# `foo` will be temporarily rebinded while executing `expr`
with_bindings(paste(foo, bar), foo = "rebinded")
paste(foo, bar)
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