parser(match): add MVP type patterns (IntegerBox(x)/StringBox(s)) via AST If-chain; keep literal-only path using PeekExpr; add smoke app (apps/tests/match_type_pattern_basic.nyash); build + stage-2 smokes green

src/parser/declarations/box_def/members/common.rs

@@ -0,0 +1,57 @@
+//! Shared helpers for members parsing (scaffold)
+use crate::parser::{NyashParser, ParseError};
+use crate::parser::common::ParserUtils;
+use crate::tokenizer::TokenType;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum MemberKind {
+    Field,
+    Method,
+    Constructor,
+    PropertyComputed,
+    PropertyOnce,
+    PropertyBirthOnce,
+}
+
+/// Decide member kind via simple lookahead (scaffold placeholder)
+pub fn classify_member(p: &mut NyashParser) -> Result<MemberKind, ParseError> {
+    // block-first: { body } as (once|birth_once)? name : Type
+    if crate::config::env::unified_members() && p.match_any_token(&[TokenType::LBRACE]) {
+        return Ok(MemberKind::PropertyComputed);
+    }
+
+    // Constructors by keyword or name
+    match &p.current_token().token_type {
+        TokenType::PACK | TokenType::BIRTH => {
+            if p.peek_token() == &TokenType::LPAREN { return Ok(MemberKind::Constructor); }
+        }
+        TokenType::IDENTIFIER(name) if (name == "init" || name == "birth" || name == "pack")
+            && p.peek_token() == &TokenType::LPAREN => {
+            return Ok(MemberKind::Constructor);
+        }
+        _ => {}
+    }
+
+    // Method: ident '(' ...
+    if matches!(&p.current_token().token_type, TokenType::IDENTIFIER(_))
+        && p.peek_token() == &TokenType::LPAREN
+    {
+        return Ok(MemberKind::Method);
+    }
+
+    // Field: [weak] ident ':' Type
+    if p.match_any_token(&[TokenType::WEAK]) {
+        // weak IDENT ':'
+        // do not consume; use peek via offset: current is WEAK, next should be IDENT, then ':'
+        // We only classify; the main parser will handle errors.
+        return Ok(MemberKind::Field);
+    }
+    if matches!(&p.current_token().token_type, TokenType::IDENTIFIER(_))
+        && p.peek_token() == &TokenType::COLON
+    {
+        return Ok(MemberKind::Field);
+    }
+
+    // Default: treat as method for graceful recovery
+    Ok(MemberKind::Method)
+}