From aff36c2bbb89f7954717238ba6312bc26f506438 Mon Sep 17 00:00:00 2001
From: Jon Harmon <jonthegeek@gmail.com>
Date: Fri, 23 Feb 2024 11:14:26 -0600
Subject: [PATCH] Flatten lists when possible. (#68)

Only for chr right now. Will need to refactor and generalize this.
---
 DESCRIPTION                  |  4 ++--
 NAMESPACE                    |  2 ++
 R/to_chr.R                   |  7 +++++++
 tests/testthat/test-to_chr.R | 15 +++++++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 8d18261..9655d0d 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: stbl
 Title: Stabilize Function Arguments
-Version: 0.0.0.9000
+Version: 0.0.0.9001
 Authors@R: 
     person("Jon", "Harmon", , "jonthegeek@gmail.com", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-4781-4346"))
@@ -24,4 +24,4 @@ Config/testthat/edition: 3
 Config/testthat/parallel: true
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.0
diff --git a/NAMESPACE b/NAMESPACE
index 04f34b4..386f94a 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -7,8 +7,10 @@ S3method(to_chr,default)
 S3method(to_chr,list)
 S3method(to_fct,"NULL")
 S3method(to_fct,character)
+S3method(to_fct,data.frame)
 S3method(to_fct,default)
 S3method(to_fct,factor)
+S3method(to_fct,list)
 S3method(to_int,"NULL")
 S3method(to_int,character)
 S3method(to_int,complex)
diff --git a/R/to_chr.R b/R/to_chr.R
index 8074cbe..bfa1bce 100644
--- a/R/to_chr.R
+++ b/R/to_chr.R
@@ -52,6 +52,13 @@ to_chr.list <- function(x,
                         x_arg = caller_arg(x),
                         call = caller_env(),
                         x_class = object_type(x)) {
+  flat <- unlist(x)
+  if (length(flat) == length(x)) {
+    if (length(flat) == 1) {
+      flat <- flat[[1]]
+    }
+    return(to_chr(flat))
+  }
   .stop_cant_coerce(
     from_class = x_class,
     to_class = "character",
diff --git a/tests/testthat/test-to_chr.R b/tests/testthat/test-to_chr.R
index 22b8ec1..fb1d6f4 100644
--- a/tests/testthat/test-to_chr.R
+++ b/tests/testthat/test-to_chr.R
@@ -68,6 +68,21 @@ test_that("to_chr() works for other things", {
   )
 })
 
+test_that("to_chr() tries to flatten lists", {
+  expect_identical(
+    to_chr(list("a", "b")),
+    c("a", "b")
+  )
+  expect_identical(
+    to_chr(list(1, 2)),
+    c("1", "2")
+  )
+  expect_identical(
+    to_chr(list("a")),
+    c("a")
+  )
+})
+
 test_that("to_chr() fails gracefully for weird cases", {
   wrapper <- function(wrapper_val, ...) {
     return(to_chr(wrapper_val, ...))