Execute Code Within a Trace — with

Creates a new trace, evaluates the expression, ends the trace, and optionally exports it. The trace is available via current_trace() during evaluation.

Usage

with_trace(name, expr, ..., exporter = NULL)

Arguments

name: Name for the trace.
expr: Expression to evaluate.
...: Additional arguments passed to Trace$new() as metadata.
exporter: Optional exporter. If NULL, uses the default exporter (if set).

Value

The result of evaluating expr.

Thread Safety

The context stack is process-global, following R's standard single-threaded assumption. Parallel workers spawned via future, callr, or parallel receive isolated copies of the stack, so spans created in those workers will not appear in the parent trace. This is consistent with how options(), par(), and Sys.setenv() behave in base R.

Examples

# Trace a block of code
result <- with_trace("my-operation", {
  Sys.sleep(0.01)
  1 + 1
})
result
#> [1] 2

# With an exporter
result <- with_trace("traced-op", {
  10 * 2
}, exporter = console_exporter(verbose = FALSE))
#> --- Trace: traced-op ---
#> Status: completed
#> Duration: 0.00s
#> Spans: 0