Merge branch 'hb/stdlib/correct_fread_spec/OTP-11261' into maint

* hb/stdlib/correct_fread_spec/OTP-11261:
  Correct the specifications of io_lib:fread/2,3

3 files changed, 14 insertions, 7 deletions

diff --git a/lib/stdlib/doc/src/io_lib.xml b/lib/stdlib/doc/src/io_lib.xml
index 3dac259477..68352ffeb1 100644
--- a/lib/stdlib/doc/src/io_lib.xml
+++ b/lib/stdlib/doc/src/io_lib.xml
@@ -54,6 +54,9 @@
       <name name="fread_error"/>
     </datatype>
     <datatype>
+      <name name="fread_item"/>
+    </datatype>
+    <datatype>
       <name name="latin1_string"/>
     </datatype>
   </datatypes>
diff --git a/lib/stdlib/src/io_lib.erl b/lib/stdlib/src/io_lib.erl
index a9b6d4131e..92a086b077 100644
--- a/lib/stdlib/src/io_lib.erl
+++ b/lib/stdlib/src/io_lib.erl
@@ -83,7 +83,8 @@
 -export([write_unicode_string/1, write_unicode_char/1,
          deep_unicode_char_list/1]).
 
--export_type([chars/0, latin1_string/0, continuation/0, fread_error/0]).
+-export_type([chars/0, latin1_string/0, continuation/0,
+              fread_error/0, fread_item/0]).
 
 %%----------------------------------------------------------------------
 
@@ -106,6 +107,8 @@
                      | 'string'
                      | 'unsigned'.
 
+-type fread_item() :: string() | atom() | integer() | float().
+
 %%----------------------------------------------------------------------
 
 %% Interface calls to sub-modules.
@@ -120,7 +123,7 @@ fwrite(Format, Args) ->
 -spec fread(Format, String) -> Result when
       Format :: string(),
       String :: string(),
-      Result :: {'ok', InputList :: [term()], LeftOverChars :: string()}
+      Result :: {'ok', InputList :: [fread_item()], LeftOverChars :: string()}
               | {'more', RestFormat :: string(),
                  Nchars :: non_neg_integer(),
                  InputStack :: chars()}
@@ -135,7 +138,7 @@ fread(Chars, Format) ->
       Format :: string(),
       Return :: {'more', Continuation1 :: continuation()}
               | {'done', Result, LeftOverChars :: string()},
-      Result :: {'ok', InputList :: [term()]}
+      Result :: {'ok', InputList :: [fread_item()]}
               | 'eof'
               | {'error', {'fread', What :: fread_error()}}.
 
diff --git a/lib/stdlib/src/io_lib_fread.erl b/lib/stdlib/src/io_lib_fread.erl
index 92a34995b8..491e1f40d7 100644
--- a/lib/stdlib/src/io_lib_fread.erl
+++ b/lib/stdlib/src/io_lib_fread.erl
@@ -41,9 +41,9 @@
       Format :: string(),
       Return :: {'more', Continuation1 :: io_lib:continuation()}
               | {'done', Result, LeftOverChars :: string()},
-      Result :: {'ok', InputList :: io_lib:chars()}
+      Result :: {'ok', InputList :: [io_lib:fread_item()]}
               | 'eof'
-              | {'error', {'read', What :: io_lib:fread_error()}}.
+              | {'error', {'fread', What :: io_lib:fread_error()}}.
 
 fread([], Chars, Format) ->
     %%io:format("FREAD: ~w `~s'~n", [Format,Chars]),
@@ -101,11 +101,12 @@ fread_line(Format0, Line, N0, Results0, More, Newline) ->
 -spec fread(Format, String) -> Result when
       Format :: string(),
       String :: string(),
-      Result :: {'ok', InputList :: io_lib:chars(), LeftOverChars :: string()}
+      Result :: {'ok', InputList :: [io_lib:fread_item()],
+                 LeftOverChars :: string()}
               | {'more', RestFormat :: string(),
                  Nchars :: non_neg_integer(),
                  InputStack :: io_lib:chars()}
-              | {'error', What :: term()}.
+              | {'error', {'fread', What :: io_lib:fread_error()}}.
 
 fread(Format, Line) ->
     fread(Format, Line, 0, []).