add generics

test/fixtures/invalid/bang_postfix.ls

@@ -1 +0,0 @@
-value :: @ x: i32 -> i32 ! str { x! }

test/fixtures/invalid/bang_prefix.ls

@@ -1 +0,0 @@
-value :: @ x: str -> i32 ! str { !x }

test/fixtures/invalid/keyword_ok_identifier.ls

@@ -1 +0,0 @@
-ok :: @ value { value }

test/fixtures/invalid/keyword_some_identifier.ls

@@ -1 +0,0 @@
-some := 1

test/fixtures/invalid/legacy_some_constructor.ls

@@ -1 +0,0 @@
-value: i32?: 1->|.some

test/fixtures/invalid/legacy_some_pattern.ls

@@ -1 +0,0 @@
-value :: @ x: i32? { match x { |.some y => y; nil => 0 } }

test/fixtures/invalid/pipeline_mixed_infix.ls

@@ -1 +0,0 @@
-value :: 1 + 2->to_str

test/fixtures/valid/containers.ls

@@ -6,8 +6,8 @@ more_codes := [...codes, 'failed' => 500]
 
 empty_numbers: []i32: []
 empty_codes: [str]i32: []
-optional_numbers: []i32?: nil
-optional_elements: []{i32?}: [nil, some 1]
+optional_numbers: []i32?: |.none
+optional_elements: []{i32?}: [|.none, 1->|.some]
 
 Options :: &{
     name: str: 'default'

test/fixtures/valid/control.ls

@@ -11,10 +11,10 @@ choose_block: (bit, i32, i32) -> i32: @ (condition: bit, when_true: i32, when_fa
 first_positive: []i32 -> i32?: @ values: []i32 {
     for value in values {
         if value > 0 {
-            return some value
+            return value->|.some
         }
     }
-    nil
+    |.none
 }
 
 labelled_search: []i32 -> i32: @ values: []i32 { loop `outer {

test/fixtures/valid/pipeline_precedence.ls

@@ -0,0 +1,5 @@
+add_ten: i32 -> i32: @ value: i32 { value + 10 }
+double: i32 -> i32: @ value: i32 { value * 2 }
+
+# Stages bind tighter than prefix and infix operators: -{3->add_ten} + 2 * {3->double}.
+mixed: i32: -3->add_ten + 2 * 3->double - {1 + 1}->double

test/fixtures/valid/pipelines.ls

@@ -15,9 +15,9 @@ commented := 'value' # an inline comment preserves continuation
 computed := 1 + 2
 ->to_str
 
-fallible: i32 -> i32 ! Error: @ value: i32 { ok value }
+fallible: i32 -> i32 ! Error: @ value: i32 { value->|.ok }
 
 propagate: i32 -> i32 ! Error: @ value: i32 {
     result := {value->fallible}?
-    ok result
+    result->|.ok
 }

test/fixtures/valid/standard_signatures.ls

@@ -1,19 +0,0 @@
-use math.{pi, sqrt}
-use math as m
-use random.{Pcg32, pcg32, draw_u32}
-use time.{Duration, TimeError, duration_neg}
-use time as t
-
-circle: f64: pi
-root: f64: 4.0->sqrt
-# Host overloads are selected by the operand, so the literal is typed first.
-nine: f32: 9.0
-qualified_root: f32: nine->m.sqrt
-qualified_pi: f32: m.pi
-
-seed: u64: 42
-generator: Pcg32: seed->pcg32
-draw: u32: generator->draw_u32
-
-negate: Duration => Duration ! TimeError: duration_neg
-qualified_negate: t.Duration => t.Duration ! t.TimeError: t.duration_neg

test/fixtures/valid/wrappers.ls

@@ -1,24 +0,0 @@
-present: i32?: some 1
-absent: i32?: nil
-success: i32 ! str: ok 1
-failure: i32 ! str: err 'failed'
-piped: i32?: some 4->double
-grouped: i32?: some {4->double}
-
-double :: @ value { value * 2 }
-describe :: @ (label: str, count) -> str { label }
-
-unwrap_or: i32? -> i32: @ value {
-    match value {
-        some inner => inner
-        nil => 0
-    }
-}
-
-handle: i32 ! str -> i32: @ result {
-    match result {
-        ok value if value > 0 => value
-        ok _ => 0
-        err message => message->length
-    }
-}