feat: migrate all function literals from fn syntax to new Fn block syntax

Replace all occurrences of the old `fn` function literal syntax with the new `new Fn {|params| body}` block syntax across benchmark, test, and source files. Update the Wren compiler to handle the pipe operator as a block argument delimiter by removing `TOKEN_PIPE` from the newline-swallowing token list and adding explicit newline matching in `infixOp`. Adjust test expectations in `conditional/precedence.wren` to remove `fn`-based expressions and update `test/assignment/local.wren` to use the new syntax.

test/assignment/local.wren

@@ -1,4 +1,4 @@
-fn {
+new Fn {
   var a = "before"
   IO.print(a) // expect: before
 

test/break/closure_in_for.wren

@@ -1,7 +1,7 @@
 var f
 for (i in [1, 2, 3]) {
   var j = 4
-  f = fn IO.print(i + j)
+  f = new Fn { IO.print(i + j) }
   break
 }
 

test/break/closure_in_while.wren

@@ -1,7 +1,7 @@
 var f
 while (true) {
   var i = "i"
-  f = fn IO.print(i)
+  f = new Fn { IO.print(i) }
   break
 }
 

test/break/in_function_in_loop.wren

@@ -1,6 +1,6 @@
 var done = false
 while (!done) {
-  fn {
+  new Fn {
     break // expect error
   }
   done = true

test/closure/assign_to_closure.wren

@@ -3,13 +3,13 @@ var g = null
 
 {
   var local = "local"
-  f = fn {
+  f = new Fn {
     IO.print(local)
     local = "after f"
     IO.print(local)
   }
 
-  g = fn {
+  g = new Fn {
     IO.print(local)
     local = "after g"
     IO.print(local)

test/closure/close_over_function_parameter.wren

@@ -1,7 +1,7 @@
 var f = null
 
-fn(param) {
-  f = fn {
+new Fn {|param|
+  f = new Fn {
     IO.print(param)
   }
 }.call("param")

test/closure/close_over_method_parameter.wren

@@ -2,7 +2,7 @@ var f = null
 
 class Foo {
   method(param) {
-    f = fn {
+    f = new Fn {
       IO.print(param)
     }
   }

test/closure/closed_closure_in_function.wren

@@ -2,7 +2,7 @@ var f = null
 
 {
   var local = "local"
-  f = fn {
+  f = new Fn {
     IO.print(local)
   }
 }

test/closure/nested_closure.wren

@@ -1,12 +1,12 @@
 var f = null
 
-fn {
+new Fn {
   var a = "a"
-  fn {
+  new Fn {
     var b = "b"
-    fn {
+    new Fn {
       var c = "c"
-      f = fn {
+      f = new Fn {
         IO.print(a)
         IO.print(b)
         IO.print(c)

test/closure/open_closure_in_function.wren

@@ -1,6 +1,6 @@
 {
   var local = "local"
-  fn {
+  new Fn {
     IO.print(local) // expect: local
   }.call
 }

test/closure/reference_closure_multiple_times.wren

@@ -2,7 +2,7 @@ var f = null
 
 {
   var a = "a"
-  f = fn {
+  f = new Fn {
     IO.print(a)
     IO.print(a)
   }

test/closure/reuse_closure_slot.wren

@@ -3,7 +3,7 @@
 
   {
     var a = "a"
-    f = fn IO.print(a)
+    f = new Fn { IO.print(a) }
   }
 
   {

test/closure/use_global_in_function.wren

@@ -1,6 +1,6 @@
 var global = "global"
 // TODO: Forward reference to global declared after use.
 
-fn {
+new Fn {
   IO.print(global) // expect: global
 }.call

test/conditional/precedence.wren

@@ -16,7 +16,6 @@ IO.print(!false ? 1 : 2) // expect: 1
 IO.print(~0 ? 1 : 2) // expect: 1
 IO.print(3 is Num ? 1 : 2) // expect: 1
 IO.print(new Foo ? 1 : 2) // expect: 1
-IO.print(fn true ? 1 : 2) // expect: <fn>
 
 var a = 0
 IO.print(a = 3 ? 1 : 2) // expect: 1
@@ -34,8 +33,6 @@ IO.print(true ? !true : 2) // expect: false
 IO.print(true ? ~0 : 2) // expect: 4294967295
 IO.print(true ? 3 is Bool : 2) // expect: false
 IO.print(true ? new Foo : 2) // expect: instance of Foo
-// TODO: Is this what we want?
-IO.print(true ? fn 1 : 2) // expect: <fn>
 
 IO.print(true ? a = 5 : 2) // expect: 5
 IO.print(a) // expect: 5
@@ -52,7 +49,6 @@ IO.print(false ? 1 : !false) // expect: true
 IO.print(false ? 1 : ~0) // expect: 4294967295
 IO.print(false ? 1 : 3 is Num) // expect: true
 IO.print(false ? 1 : new Foo) // expect: instance of Foo
-IO.print(false ? 1 : fn 2) // expect: <fn>
 
 // Associativity.
 IO.print(true ? 2 : true ? 4 : 5) // expect: 2

test/fiber/closure.wren

@@ -3,16 +3,16 @@ var closure
 
 {
   var a = "before"
-  fiber = Fiber.create(fn {
+  fiber = Fiber.create {
     IO.print(a)
     Fiber.yield
     a = "after"
     Fiber.yield
     IO.print(a)
     a = "final"
-  })
+  }
 
-  closure = fn {
+  closure = new Fn {
     IO.print(a)
   }
 }

test/field/closure.wren

@@ -2,11 +2,11 @@ class Foo {
   new { _field = "Foo field" }
 
   closeOverGet {
-    return fn { return _field }
+    return new Fn { _field }
   }
 
   closeOverSet {
-    return fn { _field = "new value" }
+    return new Fn { _field = "new value" }
   }
 }
 

test/field/in_fn_in_static_method.wren

@@ -1,5 +1,5 @@
 class Foo {
   static bar {
-    fn _field = "wat" // expect error
+    new Fn { _field = "wat" } // expect error
   }
 }

test/for/close_over_loop_variable.wren

@@ -1,7 +1,7 @@
 var list = []
 
 for (i in [1, 2, 3]) {
-  list.add(fn IO.print(i))
+  list.add(new Fn { IO.print(i) })
 }
 
 for (f in list) f.call

test/for/closure_in_body.wren

@@ -2,7 +2,7 @@ var list = []
 
 for (i in [1, 2, 3]) {
   var j = i + 1
-  list.add(fn IO.print(j))
+  list.add(new Fn { IO.print(j) })
 }
 
 for (f in list) f.call

test/for/only_evaluate_sequence_once.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   IO.print("evaluate sequence")
   return [1, 2, 3]
 }

test/for/return_closure.wren

@@ -1,6 +1,6 @@
-var f = fn {
+var f = new Fn {
   for (i in [1, 2, 3]) {
-    return fn IO.print(i)
+    return new Fn { IO.print(i) }
   }
 }
 

test/for/return_inside.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   for (i in [1, 2, 3]) {
     return i
   }

test/function/call_extra_arguments.wren

@@ -1,7 +1,7 @@
-var f0 = fn IO.print("zero")
-var f1 = fn(a) IO.print("one " + a)
-var f2 = fn(a, b) IO.print("two " + a + " " + b)
-var f3 = fn(a, b, c) IO.print("three " + a + " " + b + " " + c)
+var f0 = new Fn { IO.print("zero") }
+var f1 = new Fn {|a| IO.print("one " + a) }
+var f2 = new Fn {|a, b| IO.print("two " + a + " " + b) }
+var f3 = new Fn {|a, b, c| IO.print("three " + a + " " + b + " " + c) }
 
 f0.call("a") // expect: zero
 f0.call("a", "b") // expect: zero

test/function/call_missing_arguments.wren

@@ -1,2 +1,2 @@
-var f2 = fn(a, b) IO.print(a + b)
+var f2 = new Fn {|a, b| IO.print(a + b) }
 f2.call("a") // expect runtime error: Function expects more arguments.

test/function/empty_block.wren

@@ -1,2 +1,2 @@
-var f = fn {}
+var f = new Fn {}
 IO.print(f.call) // expect: null

test/function/equality.wren

@@ -1,16 +1,16 @@
 // Not structurally equal.
-IO.print((fn 123) == (fn 123))  // expect: false
-IO.print((fn 123) != (fn 123))  // expect: true
+IO.print(new Fn { 123 } == new Fn { 123 })  // expect: false
+IO.print(new Fn { 123 } != new Fn { 123 })  // expect: true
 
 // Not equal to other types.
-IO.print((fn 123) == 1)         // expect: false
-IO.print((fn 123) == false)     // expect: false
-IO.print((fn 123) == "fn 123")  // expect: false
-IO.print((fn 123) != 1)         // expect: true
-IO.print((fn 123) != false)     // expect: true
-IO.print((fn 123) != "fn 123")  // expect: true
+IO.print(new Fn { 123 } == 1)         // expect: false
+IO.print(new Fn { 123 } == false)     // expect: false
+IO.print(new Fn { 123 } == "fn 123")  // expect: false
+IO.print(new Fn { 123 } != 1)         // expect: true
+IO.print(new Fn { 123 } != false)     // expect: true
+IO.print(new Fn { 123 } != "fn 123")  // expect: true
 
 // Equal by identity.
-var f = fn 123
+var f = new Fn { 123 }
 IO.print(f == f) // expect: true
 IO.print(f != f) // expect: false

test/function/parameters.wren

@@ -1,50 +1,50 @@
-var f0 = fn 0
+var f0 = new Fn { 0 }
 IO.print(f0.call) // expect: 0
 
-var f1 = fn(a) a
+var f1 = new Fn {|a| a }
 IO.print(f1.call(1)) // expect: 1
 
-var f2 = fn(a, b) a + b
+var f2 = new Fn {|a, b| a + b }
 IO.print(f2.call(1, 2)) // expect: 3
 
-var f3 = fn(a, b, c) a + b + c
+var f3 = new Fn {|a, b, c| a + b + c }
 IO.print(f3.call(1, 2, 3)) // expect: 6
 
-var f4 = fn(a, b, c, d) a + b + c + d
+var f4 = new Fn {|a, b, c, d| a + b + c + d }
 IO.print(f4.call(1, 2, 3, 4)) // expect: 10
 
-var f5 = fn(a, b, c, d, e) a + b + c + d + e
+var f5 = new Fn {|a, b, c, d, e| a + b + c + d + e }
 IO.print(f5.call(1, 2, 3, 4, 5)) // expect: 15
 
-var f6 = fn(a, b, c, d, e, f) a + b + c + d + e + f
+var f6 = new Fn {|a, b, c, d, e, f| a + b + c + d + e + f }
 IO.print(f6.call(1, 2, 3, 4, 5, 6)) // expect: 21
 
-var f7 = fn(a, b, c, d, e, f, g) a + b + c + d + e + f + g
+var f7 = new Fn {|a, b, c, d, e, f, g| a + b + c + d + e + f + g }
 IO.print(f7.call(1, 2, 3, 4, 5, 6, 7)) // expect: 28
 
-var f8 = fn(a, b, c, d, e, f, g, h) a + b + c + d + e + f + g + h
+var f8 = new Fn {|a, b, c, d, e, f, g, h| a + b + c + d + e + f + g + h }
 IO.print(f8.call(1, 2, 3, 4, 5, 6, 7, 8)) // expect: 36
 
-var f9 = fn(a, b, c, d, e, f, g, h, i) a + b + c + d + e + f + g + h + i
+var f9 = new Fn {|a, b, c, d, e, f, g, h, i| a + b + c + d + e + f + g + h + i }
 IO.print(f9.call(1, 2, 3, 4, 5, 6, 7, 8, 9)) // expect: 45
 
-var f10 = fn(a, b, c, d, e, f, g, h, i, j) a + b + c + d + e + f + g + h + i + j
+var f10 = new Fn {|a, b, c, d, e, f, g, h, i, j| a + b + c + d + e + f + g + h + i + j }
 IO.print(f10.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // expect: 55
 
-var f11 = fn(a, b, c, d, e, f, g, h, i, j, k) a + b + c + d + e + f + g + h + i + j + k
+var f11 = new Fn {|a, b, c, d, e, f, g, h, i, j, k| a + b + c + d + e + f + g + h + i + j + k }
 IO.print(f11.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)) // expect: 66
 
-var f12 = fn(a, b, c, d, e, f, g, h, i, j, k, l) a + b + c + d + e + f + g + h + i + j + k + l
+var f12 = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l| a + b + c + d + e + f + g + h + i + j + k + l }
 IO.print(f12.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)) // expect: 78
 
-var f13 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m) a + b + c + d + e + f + g + h + i + j + k + l + m
+var f13 = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l, m| a + b + c + d + e + f + g + h + i + j + k + l + m }
 IO.print(f13.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)) // expect: 91
 
-var f14 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n) a + b + c + d + e + f + g + h + i + j + k + l + m + n
+var f14 = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l, m, n| a + b + c + d + e + f + g + h + i + j + k + l + m + n }
 IO.print(f14.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)) // expect: 105
 
-var f15 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) a + b + c + d + e + f + g + h + i + j + k + l + m + n + o
+var f15 = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l, m, n, o| a + b + c + d + e + f + g + h + i + j + k + l + m + n + o }
 IO.print(f15.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)) // expect: 120
 
-var f16 = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p
+var f16 = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p| a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p }
 IO.print(f16.call(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)) // expect: 136

test/function/syntax.wren

@@ -1,25 +1,23 @@
 // Single expression body.
-(fn IO.print("ok")).call // expect: ok
-
-// TODO: Precedence of fn body.
+new Fn { IO.print("ok") }.call // expect: ok
 
 // Curly body.
-fn {
+new Fn {
   IO.print("ok") // expect: ok
 }.call
 
 // No trailing newline.
-fn {
+new Fn {
   IO.print("ok") }.call // expect: ok
 
 // Multiple expressions.
-fn {
+new Fn {
   IO.print("1") // expect: 1
   IO.print("2") // expect: 2
 }.call
 
 // Extra newlines.
-fn {
+new Fn {
 
 
   IO.print("1") // expect: 1

test/function/to_string.wren

@@ -1 +1 @@
-IO.print(fn {}) // expect: <fn>
+IO.print(new Fn {}) // expect: <fn>

test/function/too_many_parameters.wren

@@ -1 +1 @@
-var f = fn(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) { "!" } // expect error
+var f = new Fn {|a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q| "!" } // expect error

test/function/type.wren

@@ -1,4 +1,4 @@
-IO.print((fn 0) is Fn)      // expect: true
-IO.print((fn 0) is Object)  // expect: true
-IO.print((fn 0) is String)  // expect: false
-IO.print((fn 0).type == Fn) // expect: true
+IO.print(new Fn { 0 } is Fn)      // expect: true
+IO.print(new Fn { 0 } is Object)  // expect: true
+IO.print(new Fn { 0 } is String)  // expect: false
+IO.print(new Fn { 0 }.type == Fn) // expect: true

test/inheritance/inherited_fields_in_closure.wren

@@ -2,11 +2,11 @@ class Foo {
   new { _field = "Foo field" }
 
   closeOverFooGet {
-    return fn { return fn { return _field } }
+    return new Fn { new Fn { _field } }
   }
 
   closeOverFooSet {
-    return fn { return fn { _field = "new foo value" } }
+    return new Fn { new Fn { _field = "new foo value" } }
   }
 }
 
@@ -17,11 +17,11 @@ class Bar is Foo {
   }
 
   closeOverBarGet {
-    return fn { return fn { return _field } }
+    return new Fn { new Fn { _field } }
   }
 
   closeOverBarSet {
-    return fn { return fn { _field = "new bar value" } }
+    return new Fn { new Fn { _field = "new bar value" } }
   }
 }
 

test/is/is.wren

@@ -1,6 +1,6 @@
 IO.print(Num is Class) // expect: true
 IO.print(true is Bool) // expect: true
-IO.print((fn 1) is Fn) // expect: true
+IO.print(new Fn { 1 } is Fn) // expect: true
 IO.print(123 is Num) // expect: true
 IO.print(null is Null) // expect: true
 IO.print("s" is String) // expect: true
@@ -8,7 +8,7 @@ IO.print("s" is String) // expect: true
 IO.print(Num is Bool) // expect: false
 IO.print(null is Class) // expect: false
 IO.print(true is Fn) // expect: false
-IO.print((fn 1) is Num) // expect: false
+IO.print(new Fn { 1 } is Num) // expect: false
 IO.print("s" is Null) // expect: false
 IO.print(123 is String) // expect: false
 
@@ -16,7 +16,7 @@ IO.print(123 is String) // expect: false
 IO.print(Num is Object) // expect: true
 IO.print(null is Object) // expect: true
 IO.print(true is Object) // expect: true
-IO.print((fn 1) is Object) // expect: true
+IO.print(new Fn { 1 } is Object) // expect: true
 IO.print("s" is Object) // expect: true
 IO.print(123 is Object) // expect: true
 
@@ -24,7 +24,7 @@ IO.print(123 is Object) // expect: true
 IO.print(Num is Class) // expect: true
 IO.print(null is Class) // expect: false
 IO.print(true is Class) // expect: false
-IO.print((fn 1) is Class) // expect: false
+IO.print(new Fn { 1 } is Class) // expect: false
 IO.print("s" is Class) // expect: false
 IO.print(123 is Class) // expect: false
 

test/limit/long_function.wren

@@ -1,4 +1,4 @@
-fn {
+new Fn {
   IO.print(1) // expect: 1
   IO.print(2) // expect: 2
   IO.print(3) // expect: 3

test/limit/many_constants.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   1; 2; 3; 4; 5; 6; 7; 8;
   9; 10; 11; 12; 13; 14; 15; 16;
   17; 18; 19; 20; 21; 22; 23; 24;

test/list/map.wren

@@ -1,3 +1,3 @@
 var a = [1, 2, 3]
-var b = a.map(fn (x) x + 1)
+var b = a.map {|x| x + 1 }
 IO.print(b) // expect: [2, 3, 4]

test/list/where.wren

@@ -1,6 +1,6 @@
 var a = [1, 2, 3]
-var b = a.where(fn (x) x > 1)
+var b = a.where {|x| x > 1 }
 IO.print(b) // expect: [2, 3]
 
-var c = a.where(fn (x) x > 10)
+var c = a.where {|x| x > 10 }
 IO.print(c) // expect: []

test/range/map.wren

@@ -1,3 +1,3 @@
 var a = 1..3
-var b = a.map(fn (x) x + 1)
+var b = a.map {|x| x + 1 }
 IO.print(b) // expect: [2, 3, 4]

test/range/where.wren

@@ -1,6 +1,6 @@
 var a = 1..3
-var b = a.where(fn (x) x > 1)
+var b = a.where {|x| x > 1 }
 IO.print(b) // expect: [2, 3]
 
-var c = a.where(fn (x) x > 10)
+var c = a.where {|x| x > 10 }
 IO.print(c) // expect: []

test/return/after_else.wren

@@ -1,3 +1,3 @@
-IO.print(fn {
+IO.print(new Fn {
   if (false) "no" else return "ok"
 }.call) // expect: ok

test/return/after_if.wren

@@ -1,3 +1,3 @@
-IO.print(fn {
+IO.print(new Fn {
   if (true) return "ok"
 }.call) // expect: ok

test/return/after_while.wren

@@ -1,3 +1,3 @@
-IO.print(fn {
+IO.print(new Fn {
   while (true) return "ok"
 }.call) // expect: ok

test/return/in_function.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   return "ok"
   IO.print("bad")
 }

test/return/return_null_if_brace.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   if (true) { return }
   IO.print("bad")
 }

test/return/return_null_if_newline.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   return
   IO.print("bad")
 }

test/static_field/closure.wren

@@ -2,11 +2,11 @@ class Foo {
   static initialize { __field = "Foo field" }
 
   static closeOverGet {
-    return fn { return __field }
+    return new Fn { __field }
   }
 
   static closeOverSet {
-    return fn { __field = "new value" }
+    return new Fn { __field = "new value" }
   }
 }
 

test/super/closure.wren

@@ -4,9 +4,7 @@ class Base {
 
 class Derived is Base {
   getClosure {
-    return fn {
-      return super.toString
-    }
+    return new Fn { super.toString }
   }
 
   toString { return "Derived" }

test/super/super_in_top_level_function.wren

@@ -1,3 +1,3 @@
-fn {
+new Fn {
   super.foo // expect error
 }

test/this/closure.wren

@@ -1,8 +1,6 @@
 class Foo {
   getClosure {
-    return fn {
-      return toString
-    }
+    return new Fn { toString }
   }
 
   toString { return "Foo" }

test/this/nested_class.wren

@@ -2,7 +2,7 @@ class Outer {
   method {
     IO.print(this) // expect: Outer
 
-    fn {
+    new Fn {
       IO.print(this) // expect: Outer
 
       class Inner {

test/this/nested_closure.wren

@@ -1,8 +1,8 @@
 class Foo {
   getClosure {
-    return fn {
-      return fn {
-        return fn {
+    return new Fn {
+      return new Fn {
+        return new Fn {
           return toString
         }
       }

test/this/this_in_top_level_function.wren

@@ -1,3 +1,3 @@
-fn {
+new Fn {
   this // expect error
 }

test/variable/local_collide_with_function_parameter.wren

@@ -1,3 +1,3 @@
-fn(a) {
+new Fn {|a|
   var a = "oops" // expect error
 }

test/variable/undefined_local.wren

@@ -1,3 +1,3 @@
-fn {
+new Fn {
   IO.print(notDefined)  // expect error
 }.call

test/while/closure_in_body.wren

@@ -3,7 +3,7 @@ var list = []
 var i = 1
 while (i < 4) {
   var j = i + 1
-  list.add(fn IO.print(j))
+  list.add(new Fn { IO.print(j) })
   i = i + 1
 }
 

test/while/return_closure.wren

@@ -1,7 +1,7 @@
-var f = fn {
+var f = new Fn {
   while (true) {
     var i = "i"
-    return fn IO.print(i)
+    return new Fn { IO.print(i) }
   }
 }
 

test/while/return_inside.wren

@@ -1,4 +1,4 @@
-var f = fn {
+var f = new Fn {
   while (true) {
     var i = "i"
     return i