feat!: Remove -> token in favor of => (#2177)

Author: spotandjake

compiler/src/parsing/lexer.re

@@ -273,8 +273,7 @@ let rec token = lexbuf => {
   | "/" => positioned(SLASH)
   | "|" => positioned(PIPE)
   | "-" => positioned(DASH)
-  | "->" => positioned(ARROW)
-  | "=>" => positioned(THICKARROW)
+  | "=>" => positioned(ARROW)
   | "type" => positioned(TYPE)
   | "enum" => positioned(ENUM)
   | "record" => positioned(RECORD)

compiler/src/parsing/parser.messages

@@ -20,7 +20,7 @@ module Grain_parsing = struct end
 %token <string> STRING BYTES CHAR
 %token LBRACK LBRACKRCARET RBRACK LPAREN RPAREN LBRACE RBRACE LCARET RCARET
 %token COMMA SEMI AS
-%token THICKARROW ARROW
+%token ARROW
 %token EQUAL GETS
 %token UNDERSCORE
 %token COLON QUESTION DOT ELLIPSIS
@@ -99,7 +99,6 @@ module Grain_parsing = struct end
   comma
   eos
   arrow
-  thickarrow
   equal
   const
   pattern
@@ -192,13 +191,6 @@ comma:
 arrow:
   | ARROW opt_eols {}
 
-thickarrow:
-  | THICKARROW opt_eols {}
-
-either_arrow:
-  | arrow {}
-  | thickarrow {}
-
 equal:
   | EQUAL opt_eols {}
 
@@ -324,9 +316,9 @@ data_typ:
   | qualified_uid %prec _below_infix { Type.constr ~loc:(to_loc $loc) $1 [] }
 
 typ:
-  | FUN data_typ either_arrow typ { Type.arrow ~loc:(to_loc $loc) [TypeArgument.mk ~loc:(to_loc $loc($2)) Unlabeled $2] $4 }
-  | FUN LIDENT either_arrow typ { Type.arrow ~loc:(to_loc $loc) [TypeArgument.mk ~loc:(to_loc $loc($2)) Unlabeled (Type.var ~loc:(to_loc $loc($2)) $2)] $4 }
-  | FUN lparen arg_typs? rparen either_arrow typ { Type.arrow ~loc:(to_loc $loc) (Option.value ~default:[] $3) $6 }
+  | FUN data_typ arrow typ { Type.arrow ~loc:(to_loc $loc) [TypeArgument.mk ~loc:(to_loc $loc($2)) Unlabeled $2] $4 }
+  | FUN LIDENT arrow typ { Type.arrow ~loc:(to_loc $loc) [TypeArgument.mk ~loc:(to_loc $loc($2)) Unlabeled (Type.var ~loc:(to_loc $loc($2)) $2)] $4 }
+  | FUN lparen arg_typs? rparen arrow typ { Type.arrow ~loc:(to_loc $loc) (Option.value ~default:[] $3) $6 }
   | lparen tuple_typs rparen { Type.tuple ~loc:(to_loc $loc) $2 }
   | lparen typ rparen { $2 }
   | LIDENT { Type.var ~loc:(to_loc $loc) $1 }
@@ -542,8 +534,8 @@ lam_args:
   | lseparated_nonempty_list(comma, lam_arg) comma? { $1 }
 
 lam_expr:
-  | FUN lparen lam_args? rparen thickarrow expr { Expression.lambda ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) (Option.value ~default:[] $3) $6 }
-  | FUN LIDENT thickarrow expr { Expression.lambda ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) [LambdaArgument.mk ~loc:(to_loc $loc($2)) (Pattern.var ~loc:(to_loc $loc($2)) (mkstr $loc($2) $2)) None] $4 }
+  | FUN lparen lam_args? rparen arrow expr { Expression.lambda ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) (Option.value ~default:[] $3) $6 }
+  | FUN LIDENT arrow expr { Expression.lambda ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) [LambdaArgument.mk ~loc:(to_loc $loc($2)) (Pattern.var ~loc:(to_loc $loc($2)) (mkstr $loc($2) $2)) None] $4 }
 
 attribute_argument:
   | STRING { mkstr $loc $1 }
@@ -583,7 +575,7 @@ when_guard:
   | opt_eols WHEN expr { $3 }
 
 match_branch:
-  | pattern ioption(when_guard) thickarrow expr { MatchBranch.mk ~loc:(to_loc $loc) $1 $4 $2 }
+  | pattern ioption(when_guard) arrow expr { MatchBranch.mk ~loc:(to_loc $loc) $1 $4 $2 }
 
 match_branches:
   | lseparated_nonempty_list(comma, match_branch) comma? { $1 }

compiler/src/parsing/parser.mly

@@ -67,7 +67,6 @@ let inject_fun =
 
 let is_triggering_token =
   fun
-  | (THICKARROW, _, _)
   | (ARROW, _, _) => true
   | _ => false;
 
@@ -191,7 +190,7 @@ and lex_balanced_step = (state, closing, acc, tok) => {
       lex_balanced(~push=DiscoverFunctions, state, RPAREN, acc),
     )
   | ((LPAREN, _, _), _) => check_lparen_fn(state, closing, acc)
-  | ((THICKARROW, _, _), _) when ignore_fns(state) =>
+  | ((ARROW, _, _), _) when ignore_fns(state) =>
     // When in a context where we're not looking for toplevel functions,
     // the thing that appears immediately after an arrow could be a
     // function, so we need to check for that

compiler/src/parsing/wrapped_lexer.re

@@ -33,6 +33,6 @@ let stringTailMatcher =  (toMatch, len) =>
     true
   }
 
-let f: Number -> (Number, Number) -> Number = a => (b, c) => a + b + c
+let f: Number => (Number, Number) => Number = a => (b, c) => a + b + c
 
 let namedArg: (?suffix: String) => String = (suffix="") => suffix

compiler/test/grainfmt/function_params.input.gr

@@ -21,7 +21,7 @@ export let _RESERVED_RUNTIME_SPACE: WasmI32
  * @param nbytes: The number of bytes to allocate
  * @returns The pointer to the allocated region (8-byte aligned), or -1 if the allocation failed.
  */
-export let malloc: (nbytes: WasmI32) -> WasmI32
+export let malloc: (nbytes: WasmI32) => WasmI32
 
 /**
  * Frees the given allocated pointer.
@@ -63,22 +63,22 @@ The interface provided by the `GC` module is similar (but not identical) to that
  * @param size: The number of bytes to allocate
  * @returns The pointer to the allocated region
  */
-export let malloc = (size: WasmI32) -> WasmI32
+export let malloc = (size: WasmI32) => WasmI32
 
 /**
  * Frees the given pointer. Using this pointer after it has been freed will result in undefined behavior.
  *
  * @param userPtr: The pointer to free
  */
-export let free = (userPtr: WasmI32) -> Void
+export let free = (userPtr: WasmI32) => Void
 
 /**
  * Increments the reference count of the given pointer.
  *
  * @param userPtr: The pointer whose reference count should be incremented
  * @returns The given pointer
  */
-export let incRef = (userPtr: WasmI32) -> WasmI32
+export let incRef = (userPtr: WasmI32) => WasmI32
 
 /**
  * Decrements the reference count of the given pointer. An error is thrown if the
@@ -87,7 +87,7 @@ export let incRef = (userPtr: WasmI32) -> WasmI32
  * @param userPtr: The pointer whose reference count should be decremented
  * @returns The given pointer
  */
-export let decRef = (userPtr: WasmI32) -> WasmI32
+export let decRef = (userPtr: WasmI32) => WasmI32
 ```
 
 The reference count-managing functions are safe to use with non-pointers; if a non-pointer is passed