fix io.debug to behave the same on Erlang and JavaScript (#308)

2 files changed, 13 insertions, 23 deletions

diff --git a/src/gleam/io.gleam b/src/gleam/io.gleam
index 5a485c9..3e4fadb 100644
--- a/src/gleam/io.gleam
+++ b/src/gleam/io.gleam
@@ -1,3 +1,5 @@
+import gleam/string
+
 /// Writes a string to standard output.
 ///
 /// If you want your output to be printed on its own line see `println`.
@@ -48,7 +50,7 @@ if javascript {
     "../gleam_stdlib.mjs" "log"
 }
 
-/// Prints a value to standard output using Erlang syntax.
+/// Prints a value to standard output (stdout) yielding Gleam syntax.
 ///
 /// The value is returned after being printed so it can be used in pipelines.
 ///
@@ -73,24 +75,9 @@ if javascript {
 /// ```
 ///
 pub fn debug(term: anything) -> anything {
-  debug_print(term)
   term
-}
-
-if erlang {
-  fn debug_print(term: anything) -> DoNotLeak {
-    erlang_fwrite("~tp\n", [term])
-  }
-}
+  |> string.inspect
+  |> println
 
-if javascript {
-  external fn debug_print(anything) -> Nil =
-    "../gleam_stdlib.mjs" "debug"
-}
-
-if erlang {
-  external type DoNotLeak
-
-  external fn erlang_fwrite(String, List(a)) -> DoNotLeak =
-    "io" "fwrite"
+  term
 }
diff --git a/src/gleam/string.gleam b/src/gleam/string.gleam
index d06e2dd..a25bdd7 100644
--- a/src/gleam/string.gleam
+++ b/src/gleam/string.gleam
@@ -6,6 +6,7 @@ import gleam/list
 import gleam/option.{None, Option, Some}
 import gleam/order
 import gleam/string_builder
+import gleam/string_builder.{StringBuilder}
 
 if erlang {
   import gleam/result
@@ -824,17 +825,19 @@ pub fn capitalise(s: String) -> String {
   }
 }
 
-pub fn inspect(value: a) -> String {
-  do_inspect(value)
+/// Returns a `String` representation of values in Gleam syntax.
+///
+pub fn inspect(term: anything) -> String {
+  do_inspect(term)
   |> string_builder.to_string
 }
 
 if javascript {
-  external fn do_inspect(value: a) -> string_builder.StringBuilder =
+  external fn do_inspect(term: anything) -> StringBuilder =
     "../gleam.mjs" "inspect"
 }
 
 if erlang {
-  external fn do_inspect(value: a) -> string_builder.StringBuilder =
+  external fn do_inspect(term: anything) -> StringBuilder =
     "gleam_stdlib" "inspect"
 }