Optional C Strings

6 files changed, 31 insertions, 10 deletions

diff --git a/builtins/c_string.c b/builtins/c_string.c
index 3e3ef740..c7c7a563 100644
--- a/builtins/c_string.c
+++ b/builtins/c_string.c
@@ -46,7 +46,7 @@ PUREFUNC public uint64_t CString$hash(const char **c_str)
 public const TypeInfo CString$info = {
     .size=sizeof(char*),
     .align=__alignof__(char*),
-    .tag=CustomInfo,
+    .tag=CStringInfo,
     .CustomInfo={.as_text=(void*)CString$as_text, .compare=(void*)CString$compare, .equal=(void*)CString$equal, .hash=(void*)CString$hash},
 };
 
diff --git a/builtins/functions.c b/builtins/functions.c
index ed0889d4..e506fe1c 100644
--- a/builtins/functions.c
+++ b/builtins/functions.c
@@ -118,7 +118,7 @@ PUREFUNC public uint64_t generic_hash(const void *obj, const TypeInfo *type)
         errx(1, "Optional hash not implemented");
     }
     case EmptyStructInfo: return 0;
-    case CustomInfo: case StructInfo: case EnumInfo: // These all share the same info
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
         if (!type->CustomInfo.hash)
             goto hash_data;
         return type->CustomInfo.hash(obj, type);
@@ -143,7 +143,7 @@ PUREFUNC public int32_t generic_compare(const void *x, const void *y, const Type
         errx(1, "Optional compare not implemented");
     }
     case EmptyStructInfo: return 0;
-    case CustomInfo: case StructInfo: case EnumInfo: // These all share the same info
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
         if (!type->CustomInfo.compare)
             goto compare_data;
         return type->CustomInfo.compare(x, y, type);
@@ -167,7 +167,7 @@ PUREFUNC public bool generic_equal(const void *x, const void *y, const TypeInfo
     case OptionalInfo: {
         errx(1, "Optional equal not implemented");
     }
-    case CustomInfo: case StructInfo: case EnumInfo: // These all share the same info
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
         if (!type->CustomInfo.equal)
             goto use_generic_compare;
         return type->CustomInfo.equal(x, y, type);
@@ -191,7 +191,7 @@ public Text_t generic_as_text(const void *obj, bool colorize, const TypeInfo *ty
     case EmptyStructInfo: return colorize ?
                       Text$concat(Text("\x1b[0;1m"), Text$from_str(type->EmptyStructInfo.name), Text("\x1b[m()"))
                           : Text$concat(Text$from_str(type->EmptyStructInfo.name), Text("()"));
-    case CustomInfo: case StructInfo: case EnumInfo: // These all share the same info
+    case CustomInfo: case StructInfo: case EnumInfo: case CStringInfo: // These all share the same info
         if (!type->CustomInfo.as_text)
             fail("No text function provided for type!\n");
         return type->CustomInfo.as_text(obj, colorize, type);
diff --git a/builtins/optionals.c b/builtins/optionals.c
index 88f08097..93fac2ed 100644
--- a/builtins/optionals.c
+++ b/builtins/optionals.c
@@ -42,9 +42,8 @@ static inline bool is_null(const void *obj, const TypeInfo *non_optional_type)
                 offset += non_optional_type->align - (offset % non_optional_type->align);
             return *(bool*)(obj + offset);
         }
-        case EnumInfo: {
-            return (*(int*)obj) == 0; // NULL tag
-        }
+        case EnumInfo: return (*(int*)obj) == 0; // NULL tag
+        case CStringInfo: return (*(char**)obj) == NULL;
         default: {
             Text_t t = generic_as_text(NULL, false, non_optional_type);
             errx(1, "is_null() not implemented for: %k", &t);
diff --git a/builtins/types.h b/builtins/types.h
index 38d8bdc5..a7b4bb51 100644
--- a/builtins/types.h
+++ b/builtins/types.h
@@ -18,7 +18,7 @@ typedef struct TypeInfo {
     int64_t size, align;
     struct { // Anonymous tagged union for convenience 
         enum { CustomInfo, StructInfo, EnumInfo, PointerInfo, TextInfo, ArrayInfo, ChannelInfo, TableInfo, FunctionInfo,
-            OptionalInfo, TypeInfoInfo, OpaqueInfo, EmptyStructInfo } tag;
+            OptionalInfo, TypeInfoInfo, OpaqueInfo, EmptyStructInfo, CStringInfo } tag;
         union {
             struct {
                 equal_fn_t equal;
diff --git a/compile.c b/compile.c
index cc3603ae..58cb2733 100644
--- a/compile.c
+++ b/compile.c
@@ -328,7 +328,7 @@ static CORD compile_optional_check(env_t *env, ast_t *ast)
 {
     type_t *t = get_type(env, ast);
     t = Match(t, OptionalType)->type;
-    if (t->tag == PointerType || t->tag == FunctionType)
+    if (t->tag == PointerType || t->tag == FunctionType || t->tag == CStringType || t == THREAD_TYPE)
         return CORD_all("(", compile(env, ast), " != NULL)");
     else if (t->tag == BigIntType)
         return CORD_all("((", compile(env, ast), ").small != 0)");
@@ -1688,6 +1688,8 @@ CORD compile(env_t *env, ast_t *ast)
     switch (ast->tag) {
     case Nil: {
         type_t *t = parse_type_ast(env, Match(ast, Nil)->type);
+        if (t == THREAD_TYPE) return "NULL";
+
         switch (t->tag) {
         case BigIntType: return "NULL_INT";
         case IntType: {
@@ -1705,6 +1707,7 @@ CORD compile(env_t *env, ast_t *ast)
         case TableType: return "NULL_TABLE";
         case SetType: return "NULL_TABLE";
         case TextType: return "NULL_TEXT";
+        case CStringType: return "NULL";
         case PointerType: return CORD_all("((", compile_type(t), ")NULL)");
         case ClosureType: return "NULL_CLOSURE";
         case NumType: return "nan(\"null\")";
diff --git a/test/optionals.tm b/test/optionals.tm
index a721deaa..521bba51 100644
--- a/test/optionals.tm
+++ b/test/optionals.tm
@@ -49,6 +49,12 @@ func maybe_lambda(should_i:Bool)-> func()?:
     else:
         return !func()
 
+func maybe_c_string(should_i:Bool)->CString?:
+    if should_i:
+        return ("hi":as_c_string())?
+    else:
+        return !CString
+
 func main():
     >> 5?
     = 5? : Int?
@@ -162,6 +168,19 @@ func main():
             fail("Truthy: $nope")
         else: !! Falsey: $nope
 
+    do:
+        !! ...
+        !! C Strings:
+        >> yep := maybe_c_string(yes)
+        = CString("hi")?
+        >> nope := maybe_c_string(no)
+        = !CString
+        >> if yep: >> yep
+        else: fail("Falsey: $yep")
+        >> if nope:
+            fail("Truthy: $nope")
+        else: !! Falsey: $nope
+
     if yep := maybe_int(yes):
         >> yep
         = 123 : Int