refact(rivetc+rivet): use := for for fields with default values

lib/rivet/src/ast/Expr.ri

@@ -30,7 +30,7 @@ public enum Expr < traits.Stringable {
         mut is_sym: bool;
         mut found: bool;
         mut sym: Sym;
-        mut builtin: Builtin = .Invalid();
+        mut builtin: Builtin := .Invalid();
         pos: token.Pos;
         mut type: Type;
     },
@@ -207,7 +207,7 @@ public enum Expr < traits.Stringable {
         args: []CallArg;
         vec_is_mut: bool;
         pos: token.Pos;
-        mut builtin: Builtin = .Invalid();
+        mut builtin: Builtin := .Invalid();
         mut type: Type;
     },
     Unary {

lib/rivet/src/ast/Sym.ri

@@ -48,7 +48,7 @@ public enum ABI as uint8 < traits.Stringable {
 
 #[default_value(InvalidSym())]
 public trait Sym {
-    id: usize = new_sym_id();
+    id: usize := new_sym_id();
     abi: ABI;
     mut is_public: bool;
     mut parent: ?Sym;

lib/rivet/src/ast/TypeSym.ri

@@ -17,7 +17,7 @@ public struct Field {
 public struct TypeSym < Sym {
     public mut fields: []Field;
     public mut full_fields_: []Field;
-    public mut info: TypeInfo = .Invalid();
+    public mut info: TypeInfo := .Invalid();
     public mut size: usize;
     public mut align: usize;
     public mut default_value: ?Expr;

lib/rivet/src/checker/mod.ri

@@ -14,7 +14,7 @@ public struct Checker {
     mut prefs: prefs.Prefs;
 
     mut source_file: ast.SourceFile;
-    mut sym: ast.Sym = ast.InvalidSym();
+    mut sym: ast.Sym := ast.InvalidSym();
     mut cur_fn: ast.Func;
 
     mut inside_extern: bool;

lib/rivet/src/codegen/mir/Block.ri

@@ -44,7 +44,7 @@ public enum Stmt < traits.Stringable {
     },
     Return {
         has_expr: bool;
-        expr: Expr = .Empty();
+        expr: Expr := .Empty();
     };
 
     public func to_string(self) -> string {

lib/rivet/src/parser/decls.ri

@@ -425,7 +425,7 @@ extend Parser {
                 name := self.parse_name();
                 self.expect(.Colon);
                 type := self.parse_type();
-                has_def_expr := self.accept(.Assign);
+                has_def_expr := self.accept(.DeclAssign);
                 def_expr := if has_def_expr {
                     self.parse_expr()
                 } else {

lib/rivet/src/prefs/mod.ri

@@ -45,13 +45,13 @@ public enum LinkMode as uint8 {
 #[boxed]
 public struct Prefs {
     // Target info
-    public mut target_os: sys.OS = sys.os();
-    public mut target_arch: sys.Arch = sys.arch();
-    public mut target_is_64bit: bool = sys.is_64bit();
-    public mut target_is_little_endian: bool = sys.is_little_endian();
-    public mut target_c_runtime: sys.CRuntime = sys.c_runtime();
+    public mut target_os: sys.OS := sys.os();
+    public mut target_arch: sys.Arch := sys.arch();
+    public mut target_is_64bit: bool := sys.is_64bit();
+    public mut target_is_little_endian: bool := sys.is_little_endian();
+    public mut target_c_runtime: sys.CRuntime := sys.c_runtime();
     public mut target_backend: Backend;
-    public mut target_backend_compiler: string = "cc";
+    public mut target_backend_compiler: string := "cc";
 
     // Module info
     public mut input: string;
@@ -66,7 +66,7 @@ public struct Prefs {
     public mut run_output: bool;
     public mut run_output_args: []string;
 
-    public mut library_path: []string = [rivetcLibDir, libDir];
+    public mut library_path: []string := [rivetcLibDir, libDir];
     public mut libraries_to_link: []string;
     public mut objects_to_link: []string;
 

lib/rivet/src/report/mod.ri

@@ -68,7 +68,7 @@ public func warn_builder(msg: string, pos: token.Pos) -> ReportBuilder {
 public struct ReportBuilder {
     mut kind: ReportKind;
     msg: string;
-    pos: token.Pos = token.noPos;
+    pos: token.Pos := token.noPos;
     mut attributes: []Attribute;
 
     #[inline]

lib/rivet/src/resolver/Register.ri

@@ -16,7 +16,7 @@ public struct Register {
     mut is_core_mod: bool;
 
     mut abi: ast.ABI;
-    mut sym: ast.Sym = ast.InvalidSym();
+    mut sym: ast.Sym := ast.InvalidSym();
     mut source_file: ast.SourceFile;
 
     public func walk_files(mut self, source_files: []ast.SourceFile) {

lib/rivet/src/resolver/mod.ri

@@ -19,7 +19,7 @@ public struct Resolver {
     mut table: ast.Table;
     mut prefs: prefs.Prefs;
 
-    mut sym: ast.Sym = ast.InvalidSym();
+    mut sym: ast.Sym := ast.InvalidSym();
     mut self_sym: ast.TypeSym;
     mut preludes: []Prelude;
 

lib/rivet/src/tokenizer/mod.ri

@@ -20,7 +20,7 @@ const NUM_SEP := b'_';
 public struct Tokenizer {
     table: ast.Table;
     prefs: prefs.Prefs;
-    file: string = "<internal-memory>";
+    file: string := "<internal-memory>";
     text: string;
     mut pos: usize;
     mut line: usize;

lib/std/src/flag/mod.ri

@@ -55,8 +55,8 @@ public struct FlagParser {
 	///    $ <appname> <usage_examples[1]>
 	///    $ ...
     public mut usage_examples: []string;
-    public mut default_help_label: string = "Display this help and exit.";
-    public mut default_version_label: string = "Show version information and exit.";
+    public mut default_help_label: string := "Display this help and exit.";
+    public mut default_version_label: string := "Show version information and exit.";
     public mut flags: []Flag;
     /// The current list of processed args.
     public mut args: []string;

rivetc/src/parser.py

@@ -437,7 +437,7 @@ def parse_field_decl(self, attributes, doc_comment, is_public):
         name = self.parse_name()
         self.expect(Kind.Colon)
         typ = self.parse_type()
-        has_def_expr = self.accept(Kind.Assign)
+        has_def_expr = self.accept(Kind.DeclAssign)
         def_expr = None
         if has_def_expr:
             def_expr = self.parse_expr()

tests/valid/src/embedded_structs.ri

@@ -1,5 +1,5 @@
 struct D {
-    m: uint8 = 155;
+    m: uint8 := 155;
 }
 
 struct E < D {