Stacky ☆ BEAM stack trace in Gleam

a stack trace of stack frames with module name, function name, arity, file name and line number

Best used with pprint.

gleam add stacky
gleam add pprint

Usage

import pprint
import stacky

pub fn main() {
  stacky.trace()
  |> pprint.debug
  // See the strack trace
  |> stacky.frame(0)
  |> pprint.debug
  // See the top most stack frame, from this call site
  |> stacky.gleam_module_name
  |> pprint.debug
  // See the current gleam module name, from this call site
}

stdout:

StackTrace([
  StackFrame(
    ErlangModuleName("stacky@example"),
    FunctionName("main"),
    FunctionArity(0),
    FileName("/Users/leo/local-dev/gleam/stacky/build/dev/erlang/stacky/_gleam_artefacts/stacky@example.erl"),
    ErlangLineNumber(8),
  ),
  StackFrame(
    ErlangModuleName("stacky@@main"),
    FunctionName("run"),
    FunctionArity(1),
    FileName("/Users/leo/local-dev/gleam/stacky/build/dev/erlang/stacky/_gleam_artefacts/stacky@@main.erl"),
    ErlangLineNumber(11),
  ),
  StackFrame(
    ErlangModuleName("erl_eval"),
    FunctionName("do_apply"),
    FunctionArity(7),
    FileName("erl_eval.erl"),
    ErlangLineNumber(746),
  ),
  StackFrame(
    ErlangModuleName("init"),
    FunctionName("start_it"),
    FunctionArity(1),
    FileName([
      110, 111, 45, 102, 105, 108, 101,
    ]),
    ErlangLineNumber(-1),
  ),
  StackFrame(
    ErlangModuleName("init"),
    FunctionName("start_em"),
    FunctionArity(1),
    FileName([
      110, 111, 45, 102, 105, 108, 101,
    ]),
    ErlangLineNumber(-1),
  ),
  StackFrame(
    ErlangModuleName("init"),
    FunctionName("do_boot"),
    FunctionArity(3),
    FileName([
      110, 111, 45, 102, 105, 108, 101,
    ]),
    ErlangLineNumber(-1),
  ),
])

StackFrame(
  ErlangModuleName("erl_eval"),
  FunctionName("do_apply"),
  FunctionArity(7),
  FileName("erl_eval.erl"),
  ErlangLineNumber(746),
)

"erl_eval"

Demo

gleam run -m stacky/sub_dir/example_in_sub_dir.gleam

Further documentation can be found at https://hexdocs.pm/stacky.