diff --git a/compiler/builtins/docs/Str.roc b/compiler/builtins/docs/Str.roc
index 2b6ff643b7..f5a157dd1a 100644
--- a/compiler/builtins/docs/Str.roc
+++ b/compiler/builtins/docs/Str.roc
@@ -380,29 +380,29 @@ walkBackwardsUsv : Str, { start: state, step: (state, U32 -> state) } -> state
 
 ## Return the first [Unicode Scalar Value](http://www.unicode.org/glossary/#unicode_scalar_value)
 ## in the string, along with the rest of the string after that USV.
-parseUsv : Str -> Result { usv : U32, rest : Str } [ StrWasEmpty ]*
+parseUsv : Str -> Result { answer : U32, rest : Str } [ StrWasEmpty ]*
 
 ## Return the first [extended grapheme cluster](http://www.unicode.org/glossary/#extended_grapheme_cluster)
 ## in the string, along with the rest of the string after that grapheme.
-parseGrapheme : Str -> Result { grapheme : Str, rest : Str } [ StrWasEmpty ]*
+parseGrapheme : Str -> Result { answer : Str, rest : Str } [ Expected [ Grapheme ]* Str ]*
 
 ## If the first string begins with the second, return whatever comes
 ## after the second.
 chompStr : Str, Str -> Result Str [ Expected [ ExactStr Str ]* Bytes ]*
-chompUsv, U32 -> Result Str [ Expected [ ExactUsv U32 ]* Bytes ]*
+chompUsv, U32 -> Result Str [ Expected [ Usv U32 ]* Bytes ]*
 
 ## If the string begins with digits which can represent a valid #U8, return
 ## that number along with the rest of the string after the digits.
-parseU8 : Str -> Result { u8 : U8, rest : Str } [ Expected [ NumU8 ]* Str ]*
-parseI8 : Str -> Result { i8 : I8, rest : Str } [ Expected [ NumI8 ]* Str ]*
-parseU16 : Str -> Result { u16 : U16, rest : Str } [ Expected [ NumU16 ]* Str ]*
-parseI16 : Str -> Result { i16 : I16, rest : Str } [ Expected [ NumI16 ]* Str ]*
-parseU32 : Str -> Result { u32 : U32, rest : Str } [ Expected [ NumU32 ]* Str ]*
-parseI32 : Str -> Result { i32 : I32, rest : Str } [ Expected [ NumI32 ]* Str ]*
-parseU64 : Str -> Result { u64 : U64, rest : Str } [ Expected [ NumU64 ]* Str ]*
-parseI64 : Str -> Result { i64 : I64, rest : Str } [ Expected [ NumI64 ]* Str ]*
-parseU128 : Str -> Result { u128 : U128, rest : Str } [ Expected [ NumU128 ]* Str ]*
-parseI128 : Str -> Result { i128 : I128, rest : Str } [ Expected [ NumI128 ]* Str ]*
+parseU8 : Str -> Result { answer : U8, rest : Str } [ Expected [ NumU8 ]* Str ]*
+parseI8 : Str -> Result { answer : I8, rest : Str } [ Expected [ NumI8 ]* Str ]*
+parseU16 : Str -> Result { answer : U16, rest : Str } [ Expected [ NumU16 ]* Str ]*
+parseI16 : Str -> Result { answer : I16, rest : Str } [ Expected [ NumI16 ]* Str ]*
+parseU32 : Str -> Result { answer : U32, rest : Str } [ Expected [ NumU32 ]* Str ]*
+parseI32 : Str -> Result { answer : I32, rest : Str } [ Expected [ NumI32 ]* Str ]*
+parseU64 : Str -> Result { answer : U64, rest : Str } [ Expected [ NumU64 ]* Str ]*
+parseI64 : Str -> Result { answer : I64, rest : Str } [ Expected [ NumI64 ]* Str ]*
+parseU128 : Str -> Result { answer : U128, rest : Str } [ Expected [ NumU128 ]* Str ]*
+parseI128 : Str -> Result { answer : I128, rest : Str } [ Expected [ NumI128 ]* Str ]*
 
-parseF64 : Str -> Result { u128 : U128, rest : Str } [ Expected [ NumF64 ]* Str ]*
-parseF32 : Str -> Result { i128 : I128, rest : Str } [ Expected [ NumF32 ]* Str ]*
+parseF64 : Str -> Result { answer : U128, rest : Str } [ Expected [ NumF64 ]* Str ]*
+parseF32 : Str -> Result { answer : I128, rest : Str } [ Expected [ NumF32 ]* Str ]*
diff --git a/packages/parser/src/Bytes.Parser.roc b/packages/parser/src/Bytes.Parser.roc
deleted file mode 100644
index 982d53c4c7..0000000000
--- a/packages/parser/src/Bytes.Parser.roc
+++ /dev/null
@@ -1,39 +0,0 @@
-##
-##
-## Parse an [IPv4](https://en.wikipedia.org/wiki/IPv4) address:
-##
-## parser : Parser Ip4
-## parser =
-##     a <- keep u8
-##     _ <- skip (usv '.')
-##     b <- keep u8
-##     _ <- skip (usv '.')
-##     c <- keep u8
-##     _ <- skip (usv '.')
-##     d <- keep u8
-##
-##     Parser.succeed (Ip4.fromOctets a b c d)
-
-
-interface Parser
-    exposes [ Parser ]
-    imports []
-
-Parser a :
-    [
-        @Parser (Bytes -> Result { answer : a, rest : Bytes } RawProblem)
-    ]
-
-RawProblem : [ ... ]
-
-keep : Parser a, (a -> Parser b) -> Parser b
-
-skip : Parser *, ({} -> Parser b) -> Parser b
-
-str : Parser Str
-
-u8 : Parser U8
-u8 = @Parser Str.parseU8 # TODO doesn't work for bytes!
-                         # TODO do we need a separate parser for Str vs Bytes because of encoding?  e.g. Parser.Bytes.utf8
-
-i8 : Parser I8
diff --git a/packages/parser/src/Bytes/Parser.roc b/packages/parser/src/Bytes/Parser.roc
new file mode 100644
index 0000000000..850e72a7fe
--- /dev/null
+++ b/packages/parser/src/Bytes/Parser.roc
@@ -0,0 +1,67 @@
+##
+##
+## Parse an [IPv4](https://en.wikipedia.org/wiki/IPv4) address:
+##
+##     parser : Parser Ip4
+##     parser =
+##         a <- keep u8
+##         _ <- skip (usv '.')
+##         b <- keep u8
+##         _ <- skip (usv '.')
+##         c <- keep u8
+##         _ <- skip (usv '.')
+##         d <- keep u8
+##
+##         Parser.succeed (Ip4.fromOctets a b c d)
+interface Parser
+    exposes [ Parser ]
+    imports []
+
+Parser a :
+    [
+        @Parser (Bytes -> Result { answer : a, rest : Bytes } Problem)
+    ]
+
+Problem :
+    [
+        Expected
+            [
+                NumU8,
+                NumI8,
+                NumU16,
+                NumI16,
+                NumU32,
+                NumI32,
+                NumU64,
+                NumI64,
+                NumU128,
+                NumI128,
+                NumF64,
+                NumF32,
+                Usv U32,
+                Utf8 Str,
+                Utf16Le Str,
+                Utf16Be Str,
+                GraphemeUtf8,
+                GraphemeUtf16Le,
+                GraphemeUtf16Be,
+                End,
+            ]
+            Str
+    ]
+
+keep : Parser a, (a -> Parser b) -> Parser b
+
+skip : Parser *, ({} -> Parser b) -> Parser b
+
+utf8 : Parser Str
+utf16 : Parser Str
+
+graphemeUtf8 : Parser Str
+graphemeUtf16Le : Parser Str
+graphemeUtf16Be : Parser Str
+
+usv : Parser U32
+
+u8 : Parser U8
+i8 : Parser I8