Make when context specific keyword

src/Visp.Compiler/ParseUtils.fs

@@ -34,6 +34,11 @@ let mkTokenizerWithArgs args =
                 args.PopContext()
                 args.PushContext LexContext.Member
 
+        | MATCH ->
+            if args.CurrentContext = LexContext.LParen then
+                args.PopContext()
+                args.PushContext LexContext.Match
+
         | HASH_PAREN
         | HASH_BRACKET
         | DOT_BRACKET

src/Visp.Compiler/Syntax/LexHelpers.fs

@@ -18,6 +18,7 @@ type LexContext =
     | Default
     | LParen
     | Member
+    | Match
 
 type LexContextStack() =
     let stack = new Stack<LexContext>()
@@ -223,7 +224,6 @@ let keywordTokenList =
       ("type", TYPE)
       ("union", UNION)
       ("unquote", UNQUOTE_KW)
-      ("when", WHEN)
       ("while", WHILE)
       ("yield", YIELD false)
       ("yield!", YIELD true) ]
@@ -233,7 +233,8 @@ let contextSpecificKeywords =
        [ ("get", MEMBER_GET)
          ("set", MEMBER_SET)
 
-         ]) ]
+         ])
+      (LexContext.Match, [ ("when", WHEN) ]) ]
 
 let contextSpecificKeywordsMap =
     contextSpecificKeywords

tests/Visp.Compiler.UnitTests/ParsingTests.generated.fs

@@ -10,6 +10,11 @@ namespace ParsingTests
 
 open Xunit
 
+[<VerifyXunit.UsesVerify>]
+module ``tests_while_while-1`` =
+    [<Fact>]
+    let ``can parse`` () = TestUtils.runTest "tests/while/while-1.visp"
+
 [<VerifyXunit.UsesVerify>]
 module ``tests_while_while-0`` =
     [<Fact>]

tests/Visp.Compiler.UnitTests/snapshots/tests_while_while-1.can parse.verified.txt

@@ -0,0 +1,60 @@
+// This file is auto-generated
+
+#nowarn "0020"  // unused results from functions
+
+open Visp.Runtime.Library
+
+let state = { Todo = () }
+// line 8 @"while-1.visp"
+let inline DiffByOne (lhs: array<'T>) (rhs: array<'T>) =
+  // line 9 @"while-1.visp"
+  let mutable index = 0
+  // line 10 @"while-1.visp"
+  let mutable loop = true
+  // line 11 @"while-1.visp"
+  let mutable diff = 0
+  // line 13 @"while-1.visp"
+  while CoreMethods.isTruthy(
+    if CoreMethods.isTruthy(
+      loop)
+      then
+        // line 13 @"while-1.visp"
+        CoreMethods.``lt``(index, (lhs.Length))
+      else
+        false) do
+    // line 14 @"while-1.visp"
+    let lhs =
+      // line 14 @"while-1.visp"
+      (lhs.[index])
+    // line 15 @"while-1.visp"
+    let rhs =
+      // line 15 @"while-1.visp"
+      (rhs.[index])
+    // line 17 @"while-1.visp"
+    if CoreMethods.isTruthy(
+      CoreMethods.``not``(CoreMethods.``eq?``(lhs, rhs)))
+      then
+        // line 17 @"while-1.visp"
+
+        // line 17 @"while-1.visp"
+        diff <- inc (diff)
+    // line 20 @"while-1.visp"
+    if CoreMethods.isTruthy(
+      CoreMethods.``gt``(diff, 1))
+      then
+        // line 20 @"while-1.visp"
+
+        // line 20 @"while-1.visp"
+        loop <- false
+    // line 23 @"while-1.visp"
+    index <- inc (index)
+  // line 26 @"while-1.visp"
+  CoreMethods.``eq?``(diff, 1)
+
+// line 29 @"while-1.visp"
+let visp_result_todo =
+  // line 29 @"while-1.visp"
+  printfn ("OK")
+// line 29 @"while-1.visp"
+printfn ("%A") (visp_result_todo)
+

tests/Visp.ExecutionTests/ExecutionTests.generated.fs

@@ -10,6 +10,11 @@ namespace ExecutionTests
 
 open Xunit
 
+[<VerifyXunit.UsesVerify>]
+module ``tests_while_while-1`` =
+    [<Fact>]
+    let ``can execute`` () = TestUtils.runTest "tests/while/while-1.visp"
+
 [<VerifyXunit.UsesVerify>]
 module ``tests_while_while-0`` =
     [<Fact>]

tests/Visp.ExecutionTests/snapshots/tests_while_while-1.can execute.verified.txt

@@ -0,0 +1,4 @@
+OK
+()
+
+ExitCode: 0

visp/tests/while/while-1.visp

@@ -0,0 +1,29 @@
+;; Copyright 2023 Ville Penttinen
+;; Distributed under the MIT License.
+;; https://github.com/vipentti/visp-fs/blob/main/LICENSE.md
+;;
+;; for basic syntax highlighting
+;; vim: set syntax=clojure:
+
+(fn inline DiffByOne ([lhs: array<^T>] [rhs: array<^T>])
+  (mut index 0)
+  (mut loop true)
+  (mut diff 0)
+
+  (while (and loop (< index (+Length lhs)))
+    (let lhs (.[index] lhs))
+    (let rhs (.[index] rhs))
+
+    (unless (= lhs rhs)
+      (set! diff (inc diff)))
+
+    (when (> diff 1)
+      (set! loop false))
+
+    (set! index (inc index))
+  )
+
+  (= diff 1))
+
+
+(printfn "OK")