use multi-backpassing in base64 example

compiler/parse/src/expr.rs

@@ -1224,6 +1224,8 @@ fn parse_expr_end<'a>(
                         match word2(b'<', b'-', EExpr::BackpassArrow).parse(arena, state) {
                             Err((_, fail, state)) => Err((MadeProgress, fail, state)),
                             Ok((_, _, state)) => {
+                                let min_indent = start.col;
+
                                 let parse_body = space0_before_e(
                                     move |a, s| parse_loc_expr(min_indent + 1, a, s),
                                     min_indent,

examples/benchmarks/Base64/Decode.roc

@@ -11,11 +11,8 @@ decodeBase64 = \width -> Bytes.Decode.loop loopHelp { remaining: width, string:
 loopHelp : { remaining : Nat, string : Str } -> Decoder (Bytes.Decode.Step { remaining : Nat, string : Str } Str)
 loopHelp = \{ remaining, string } ->
     if remaining >= 3 then
-        Bytes.Decode.map3
-            Bytes.Decode.u8
-            Bytes.Decode.u8
-            Bytes.Decode.u8
-            \x, y, z ->
+        x, y, z <- Bytes.Decode.map3 Bytes.Decode.u8 Bytes.Decode.u8 Bytes.Decode.u8
+
         a : U32
         a = Num.intCast x
         b : U32
@@ -33,10 +30,8 @@ loopHelp = \{ remaining, string } ->
         Bytes.Decode.succeed (Done string)
 
     else if remaining == 2 then
-        Bytes.Decode.map2
-            Bytes.Decode.u8
-            Bytes.Decode.u8
-            \x, y ->
+        x, y <- Bytes.Decode.map2 Bytes.Decode.u8 Bytes.Decode.u8
+
         a : U32
         a = Num.intCast x
         b : U32
@@ -46,9 +41,8 @@ loopHelp = \{ remaining, string } ->
 
     else
         # remaining = 1
-        Bytes.Decode.map
-            Bytes.Decode.u8
-            \x ->
+        x <- Bytes.Decode.map Bytes.Decode.u8
+
         a : U32
         a = Num.intCast x
         Done (Str.concat string (bitsToChars (Num.shiftLeftBy 16 a) 2))