feat: try/unwrap payload types, LSP format, macro paste, freestanding runtime

- Type `?`/`!` as Result/Option Ok payload (not always int); fix unwrap C types
- LSP 0.18 document formatting (bux fmt) + VS Code format-on-save
- Macro `:type` generics (Array_New<$t>) and operators-only tt paste
- Ship runtime_freestanding.c + BUX_RUNTIME=freestanding + smokes/examples

Makefile

@@ -5,12 +5,12 @@ BUILD_DIR := build
 # Project-local nimcache so CI can cache compiles (default is ~/.cache/nim).
 NIMFLAGS ?= --nimcache:nimcache
 
-EXAMPLES := hello fibonacci factorial structs enums methods algebraic_enums generics generics_struct generic_infer generic_infer2 extend_generic pattern_matching strings strings2 map result_option try_operator ownership ownership_checked ownership_release drop_early_return lifetime_elision ctfe ctfe_crc async concurrency os_time process json iter trait_bounds channel sync jwt stdlib_ergonomics tuples func_ptr map_remove array_iter_extra string_extra multi_closure iter_hof closure_control match_let string_interp iter_generic generic_infer_hof struct_tuple_pat match_block nested_patterns match_guards pattern_shadow move_field move_field_partial move_field_remaining move_field_nested move_field_ptr move_cross_fn c_precedence macro_twice macro_repeat macro_nested macro_hygiene macro_unhygienic macro_stmt_pat macro_tt macro_tt_raw macro_type collections_extra generic_enum switch is_operator
+EXAMPLES := hello fibonacci factorial structs enums methods algebraic_enums generics generics_struct generic_infer generic_infer2 extend_generic pattern_matching strings strings2 map result_option try_operator try_generic ownership ownership_checked ownership_release drop_early_return lifetime_elision ctfe ctfe_crc async concurrency os_time process json iter trait_bounds channel sync jwt stdlib_ergonomics tuples func_ptr map_remove array_iter_extra string_extra multi_closure iter_hof closure_control match_let string_interp iter_generic generic_infer_hof struct_tuple_pat match_block nested_patterns match_guards pattern_shadow move_field move_field_partial move_field_remaining move_field_nested move_field_ptr move_cross_fn c_precedence macro_twice macro_repeat macro_nested macro_hygiene macro_unhygienic macro_stmt_pat macro_tt macro_tt_raw macro_type macro_type_generic macro_op_paste collections_extra generic_enum switch is_operator
 
 # Platform smoke (macOS CI): full EXAMPLES still runs on Linux.
 EXAMPLES_SMOKE := hello ownership ownership_release strings map move_field move_field_partial move_field_remaining move_field_nested move_field_ptr move_cross_fn c_precedence macro_twice macro_repeat macro_nested macro_hygiene macro_unhygienic macro_stmt_pat macro_tt macro_tt_raw ctfe_crc
 
-.PHONY: all build dev debug test clean clean-all test-examples test-examples-smoke selfhost test-golden test-errors test-stdlib selfhost-loop lsp vscode vscode-package fmt-check docs bench test-apps test-dwarf test-selfhost-smoke test-unit test-linux-targets ensure-buxc
+.PHONY: all build dev debug test clean clean-all test-examples test-examples-smoke selfhost test-golden test-errors test-stdlib selfhost-loop lsp vscode vscode-package fmt-check docs bench test-apps test-dwarf test-selfhost-smoke test-unit test-linux-targets test-freestanding ensure-buxc
 
 all: build
 
@@ -37,7 +37,7 @@ debug: dev
 	@echo "Debug binary: buxc_debug"
 
 # Full local / sequential suite (same coverage as split CI jobs combined).
-test: build fmt-check test-examples test-errors test-stdlib test-registry test-dwarf test-drop-move test-linux-targets test-apps test-selfhost-smoke test-unit
+test: build fmt-check test-examples test-errors test-stdlib test-registry test-dwarf test-drop-move test-linux-targets test-freestanding test-apps test-selfhost-smoke test-unit
 
 # Nim unit tests + tiny CLI smoke (needs Nim + buxc).
 test-unit: ensure-buxc
@@ -212,6 +212,9 @@ test-lsp: lsp
 	@echo "=== LSP diagnostics (error underlines) smoke ==="
 	@chmod +x tools/smoke_lsp_diagnostics.sh
 	@tools/smoke_lsp_diagnostics.sh
+	@echo "=== LSP formatting smoke ==="
+	@chmod +x tools/smoke_lsp_formatting.sh
+	@tools/smoke_lsp_formatting.sh
 	@echo "=== LSP references / rename smoke ==="
 	@chmod +x tools/smoke_lsp_rename.sh
 	@tools/smoke_lsp_rename.sh
@@ -288,6 +291,13 @@ test-linux-targets: ensure-buxc
 	@chmod +x tools/smoke_linux_targets.sh
 	@tools/smoke_linux_targets.sh
 
+# post-1.0 — freestanding runtime (-ffreestanding object + BUX_RUNTIME=freestanding package)
+.PHONY: test-freestanding
+test-freestanding: ensure-buxc
+	@echo "=== Freestanding runtime smoke ==="
+	@chmod +x tools/smoke_freestanding.sh
+	@tools/smoke_freestanding.sh
+
 # Session 78 — Nexus HTTPS (self-signed) smoke
 .PHONY: test-nexus-tls
 test-nexus-tls: ensure-buxc

bootstrap/cli.nim

@@ -16,6 +16,7 @@ type
   RuntimeFlavor* = enum
     rfFull          ## rt/runtime.c — POSIX + OpenSSL
     rfMinimal       ## rt/runtime_minimal.c — thin, static/container/embed friendly
+    rfFreestanding  ## rt/runtime_freestanding.c — no-libc research spike
     rfWin           ## rt/runtime_win.c — Windows/MinGW (historical)
 
   GlobalOptions* = object
@@ -63,7 +64,7 @@ Registry / toolchain env:
   BUX_REGISTRY_INSECURE=1 Allow self-signed HTTPS registry (dev/smoke)
   BUX_CFLAGS              Extra flags appended to the C compiler line
   BUX_CC                  C compiler binary (overrides --target pick)
-  BUX_RUNTIME             full|minimal|thin|embed|win  (default: full on Unix)
+  BUX_RUNTIME             full|minimal|thin|embed|freestanding|win  (default: full on Unix)
   BUX_STATIC=1            Same as --static
 
 Global options:
@@ -136,8 +137,10 @@ proc resolveRuntimeFlavor(opts: GlobalOptions): RuntimeFlavor =
   case e
   of "full", "posix":
     return rfFull
-  of "minimal", "thin", "embed", "embedded", "freestanding":
+  of "minimal", "thin", "embed", "embedded":
     return rfMinimal
+  of "freestanding", "bare", "nolibc":
+    return rfFreestanding
   of "win", "windows":
     return rfWin
   of "":
@@ -159,10 +162,12 @@ proc runtimeFileName(flavor: RuntimeFlavor): string =
   case flavor
   of rfFull: "runtime.c"
   of rfMinimal: "runtime_minimal.c"
+  of rfFreestanding: "runtime_freestanding.c"
   of rfWin: "runtime_win.c"
 
 proc isThinRuntime(flavor: RuntimeFlavor): bool =
-  flavor in {rfMinimal, rfWin}
+  ## Thin = no OpenSSL / pthread link needs
+  flavor in {rfMinimal, rfFreestanding, rfWin}
 
 proc findOnPath(bin: string): bool =
   ## True if `bin` resolves as an executable on PATH (or is an absolute path).

bootstrap/hir_lower.nim

@@ -2101,6 +2101,10 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
   of ekTry:
     let operand = ctx.lowerExpr(expr.exprTryOperand)
     var operandType = ctx.resolveExprType(expr.exprTryOperand)
+    # Keep original type args for Ok payload (before mangling to Result_T_E)
+    let payloadArgs: seq[Type] =
+      if operandType != nil and operandType.kind == tkNamed: operandType.inner
+      else: @[]
 
     var typeName = ""
     var errTag = ""
@@ -2112,7 +2116,7 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
 
     # Upgrade bare generic enum name to concrete monomorphization.
     # Sema stores Result/Option without mangled type-args; try needs Result_int_String_Tag.
-    if ctx.genericEnums.hasKey(typeName):
+    if ctx.genericEnums.hasKey(typeName) or typeName == "Result" or typeName == "Option":
       # Prefer resolving call/ident TypeExpr with type args
       if expr.exprTryOperand != nil:
         if expr.exprTryOperand.kind == ekIdent and ctx.varTypeExprs.hasKey(expr.exprTryOperand.exprIdent):
@@ -2131,14 +2135,21 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
                (resolved.name == typeName or resolved.name.startsWith(typeName & "_")):
               typeName = resolved.name
       # Enclosing function return type (must match for `?` propagation)
-      let stillBare = operandType == nil or operandType.kind != tkNamed or
+      var stillBare = typeName == "Result" or typeName == "Option"
-                      typeName == operandType.name
       if stillBare and ctx.currentFuncRetType != nil and
          ctx.currentFuncRetType.kind == tkNamed:
         let rn = ctx.currentFuncRetType.name
         if rn.startsWith(typeName & "_"):
           typeName = rn
-      operandType = makeNamed(typeName)
+          stillBare = false
+      # Prefer mangled name from type args: Result + [String,String] → Result_String_String
+      if stillBare and payloadArgs.len > 0 and
+         (typeName == "Result" or typeName == "Option"):
+        var mangled = typeName
+        for a in payloadArgs:
+          mangled = mangled & "_" & a.toString.replace(" ", "").replace("*", "p")
+        typeName = mangled
+      operandType = Type(kind: tkNamed, name: typeName, inner: payloadArgs)
 
     # Err tag / Ok field from base or concrete name
     let baseForTags =
@@ -2157,6 +2168,41 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
       errTag = typeName & "_Err"
       okField = "Ok_0"
 
+    # Payload type (Ok_0 / Some_0) — must match T of Result<T,E>, not always int
+    var okType = makeInt()
+    if payloadArgs.len >= 1:
+      okType = payloadArgs[0]
+    else:
+      var enumSym = ctx.globalScope.lookup(typeName)
+      var enumDecl: Decl = nil
+      if enumSym != nil and enumSym.decl != nil and enumSym.decl.kind == dkEnum:
+        enumDecl = enumSym.decl
+      elif ctx.structInstMap.hasKey(typeName):
+        let (baseName, _) = ctx.structInstMap[typeName]
+        let baseSym = ctx.globalScope.lookup(baseName)
+        if baseSym != nil and baseSym.decl != nil and baseSym.decl.kind == dkEnum:
+          enumDecl = baseSym.decl
+      elif typeName.startsWith("Result_"):
+        let baseSym = ctx.globalScope.lookup("Result")
+        if baseSym != nil and baseSym.decl != nil: enumDecl = baseSym.decl
+      elif typeName.startsWith("Option_"):
+        let baseSym = ctx.globalScope.lookup("Option")
+        if baseSym != nil and baseSym.decl != nil: enumDecl = baseSym.decl
+      if enumDecl != nil:
+        var subst = initTable[string, Type]()
+        if ctx.structInstMap.hasKey(typeName):
+          var ti = 0
+          for tp in enumDecl.declEnumTypeParams:
+            if ti < ctx.structInstMap[typeName][1].len:
+              subst[tp.name] = ctx.structInstMap[typeName][1][ti]
+            inc ti
+        for variant in enumDecl.declEnumVariants:
+          for i, f in variant.fields:
+            let fieldName = variant.name & "_" & $i
+            if fieldName == okField:
+              okType = substituteType(ctx, f, subst)
+              break
+
     let tmpName = ctx.freshTryVar()
     let tmpAlloca = hirAlloca(tmpName, operandType, loc)
     let tmpVar = hirVar(tmpName, operandType, loc)
@@ -2179,8 +2225,8 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
     let dataLoad = HirNode(kind: hLoad, loadPtr: dataPtr,
                            typ: makeNamed(typeName & "_Data"), loc: loc)
     let okPtr = HirNode(kind: hFieldPtr, fieldPtrBase: dataLoad, fieldName: okField,
-                        typ: makePointer(makeInt()), loc: loc)
+                        typ: makePointer(okType), loc: loc)
-    let okLoad = HirNode(kind: hLoad, loadPtr: okPtr, typ: makeInt(), loc: loc)
+    let okLoad = HirNode(kind: hLoad, loadPtr: okPtr, typ: okType, loc: loc)
 
     ctx.pendingStmts.add(tmpAlloca)
     ctx.pendingStmts.add(tmpStore)
@@ -2193,14 +2239,66 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
 
     var errTag = "Result_Err"
     var typeName = "Result"
-    if operandType.kind == tkNamed:
+    var okField = "Ok_0"
+    if operandType != nil and operandType.kind == tkNamed:
       typeName = operandType.name
-      if typeName == "Option":
+      if typeName == "Option" or typeName.startsWith("Option_"):
-        errTag = "Option_None"
+        errTag = if typeName == "Option": "Option_None" else: typeName & "_None"
+        okField = "Some_0"
+      elif typeName == "Result":
+        errTag = "Result_Err"
+      else:
+        errTag = typeName & "_Err"
 
+    # Mangle Result + type args when still bare
+    if operandType != nil and operandType.kind == tkNamed and operandType.inner.len > 0 and
+       (typeName == "Result" or typeName == "Option"):
+      var mangled = typeName
+      for a in operandType.inner:
+        mangled = mangled & "_" & a.toString.replace(" ", "").replace("*", "p")
+      typeName = mangled
+      if typeName.startsWith("Option_"):
+        errTag = typeName & "_None"
+        okField = "Some_0"
+      else:
+        errTag = typeName & "_Err"
+        okField = "Ok_0"
+
+    var okType = makeInt()
+    if operandType != nil and operandType.kind == tkNamed and operandType.inner.len >= 1:
+      okType = operandType.inner[0]
+    else:
+      var enumDecl: Decl = nil
+      let enumSym = ctx.globalScope.lookup(
+        if typeName.startsWith("Result_"): "Result"
+        elif typeName.startsWith("Option_"): "Option"
+        else: typeName)
+      if enumSym != nil and enumSym.decl != nil and enumSym.decl.kind == dkEnum:
+        enumDecl = enumSym.decl
+      if enumDecl != nil:
+        var subst = initTable[string, Type]()
+        if ctx.structInstMap.hasKey(typeName):
+          var ti = 0
+          for tp in enumDecl.declEnumTypeParams:
+            if ti < ctx.structInstMap[typeName][1].len:
+              subst[tp.name] = ctx.structInstMap[typeName][1][ti]
+            inc ti
+        elif operandType != nil and operandType.kind == tkNamed:
+          var ti = 0
+          for tp in enumDecl.declEnumTypeParams:
+            if ti < operandType.inner.len:
+              subst[tp.name] = operandType.inner[ti]
+            inc ti
+        for variant in enumDecl.declEnumVariants:
+          for i, f in variant.fields:
+            if variant.name & "_" & $i == okField:
+              okType = substituteType(ctx, f, subst)
+
+    # Same shape as `?`: stack temporary of the Result/Option value (not a pointer).
+    # Typing the var as *Result made C emit `tmp->tag` on a value (invalid).
     let tmpName = ctx.freshTryVar()
     let tmpAlloca = hirAlloca(tmpName, operandType, loc)
-    let tmpVar = hirVar(tmpName, makePointer(operandType), loc)
+    let tmpVar = hirVar(tmpName, operandType, loc)
     let tmpStore = hirStore(tmpVar, operand, loc)
 
     let tagPtr = HirNode(kind: hFieldPtr, fieldPtrBase: tmpVar, fieldName: "tag",
@@ -2210,11 +2308,15 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
     let errConst = hirVar(errTag, makeNamed(typeName & "_Tag"), loc)
     let cond = hirBinary(tkEq, tagLoad, errConst, makeBool(), loc)
 
-    # On error: call bux_panic("unwrap failed")
+    # On error: call bux_panic("unwrap failed") then exit (do not continue with garbage)
     let panicTok = Token(kind: tkStringLiteral, text: "\"unwrap failed\"", loc: loc)
     let panicMsg = HirNode(kind: hLit, litToken: panicTok, typ: makeStr(), loc: loc)
     let panicCall = hirCall("bux_panic", @[panicMsg], makeVoid(), loc)
-    let thenBlock = hirBlock(@[panicCall], nil, makeVoid(), loc)
+    let exitLit = HirNode(kind: hLit,
+      litToken: Token(kind: tkIntLiteral, text: "1", loc: loc),
+      typ: makeInt(), loc: loc)
+    let exitCall = hirCall("bux_exit", @[exitLit], makeVoid(), loc)
+    let thenBlock = hirBlock(@[panicCall, exitCall], nil, makeVoid(), loc)
     let ifNode = HirNode(kind: hIf, ifCond: cond, ifThen: thenBlock,
                           ifElse: nil, typ: makeVoid(), loc: loc)
 
@@ -2223,9 +2325,9 @@ proc lowerExpr(ctx: var LowerCtx, expr: Expr): HirNode =
                            typ: makePointer(makeNamed(typeName & "_Data")), loc: loc)
     let dataLoad = HirNode(kind: hLoad, loadPtr: dataPtr,
                             typ: makeNamed(typeName & "_Data"), loc: loc)
-    let okPtr = HirNode(kind: hFieldPtr, fieldPtrBase: dataLoad, fieldName: "Ok_0",
+    let okPtr = HirNode(kind: hFieldPtr, fieldPtrBase: dataLoad, fieldName: okField,
-                         typ: makePointer(makeInt()), loc: loc)
+                         typ: makePointer(okType), loc: loc)
-    let okLoad = HirNode(kind: hLoad, loadPtr: okPtr, typ: makeInt(), loc: loc)
+    let okLoad = HirNode(kind: hLoad, loadPtr: okPtr, typ: okType, loc: loc)
 
     ctx.pendingStmts.add(tmpAlloca)
     ctx.pendingStmts.add(tmpStore)

bootstrap/macroexpand.nim

@@ -17,6 +17,17 @@ type
 proc emitErr(res: var MacroExpandResult, loc: SourceLocation, msg: string) =
   res.diagnostics.add(MacroDiagnostic(loc: loc, message: msg))
 
+proc isBinaryPasteOp*(k: TokenKind): bool =
+  ## Operators allowed as `$op:tt` paste into `$op($a, $b)` → `a OP b`.
+  case k
+  of tkPlus, tkMinus, tkStar, tkSlash, tkPercent, tkStarStar,
+     tkAmp, tkPipe, tkCaret, tkShl, tkShr,
+     tkAmpAmp, tkPipePipe,
+     tkEq, tkNe, tkLt, tkLe, tkGt, tkGe:
+    true
+  else:
+    false
+
 # ---------------------------------------------------------------------------
 # Deep clone (bootstrap has no Ast_Clone*)
 # ---------------------------------------------------------------------------
@@ -152,9 +163,12 @@ proc cloneExpr*(e: Expr): Expr =
     for a in e.exprCallArgs:
       result.exprCallArgs.add(cloneExpr(a))
   of ekGenericCall:
+    var gtas: seq[TypeExpr] = @[]
+    for ta in e.exprGenericTypeArgs:
+      gtas.add(cloneTypeExpr(ta))
     result = Expr(kind: ekGenericCall, loc: e.loc,
       exprGenericCallee: e.exprGenericCallee,
-      exprGenericTypeArgs: e.exprGenericTypeArgs)
+      exprGenericTypeArgs: gtas)
   of ekIndex:
     result = Expr(kind: ekIndex, loc: e.loc,
       exprIndexObj: cloneExpr(e.exprIndexObj),
@@ -165,9 +179,12 @@ proc cloneExpr*(e: Expr): Expr =
       exprFieldObj: cloneExpr(e.exprFieldObj),
       exprFieldName: e.exprFieldName)
   of ekStructInit:
+    var stas: seq[TypeExpr] = @[]
+    for ta in e.exprStructInitTypeArgs:
+      stas.add(cloneTypeExpr(ta))
     result = Expr(kind: ekStructInit, loc: e.loc,
       exprStructInitName: e.exprStructInitName,
-      exprStructInitTypeArgs: e.exprStructInitTypeArgs,
+      exprStructInitTypeArgs: stas,
       exprStructInitFields: @[])
     for f in e.exprStructInitFields:
       result.exprStructInitFields.add((f.name, cloneExpr(f.value)))
@@ -895,6 +912,12 @@ proc substExpr(e: Expr, env: MacroEnv, callLoc: SourceLocation): Expr =
   of ekRange:
     c.exprRangeLo = substExpr(c.exprRangeLo, env, callLoc)
     c.exprRangeHi = substExpr(c.exprRangeHi, env, callLoc)
+  of ekGenericCall:
+    # Array_New<$t>(…) / Foo<$t, $u> — substitute type fragments in type args
+    var gtas: seq[TypeExpr] = @[]
+    for ta in c.exprGenericTypeArgs:
+      gtas.add(substType(ta, env, callLoc))
+    c.exprGenericTypeArgs = gtas
   of ekCall:
     c.exprCallCallee = substExpr(c.exprCallCallee, env, callLoc)
     var args: seq[Expr] = @[]
@@ -950,12 +973,37 @@ proc substExpr(e: Expr, env: MacroEnv, callLoc: SourceLocation): Expr =
       argNames.add("")
     c.exprCallArgs = args
     c.exprCallArgNames = argNames
+    # Operators-only paste: `$op($a, $b)` where `$op:tt` is a bound binary operator
+    # → rebuild as `$a OP $b` (post-1.0).
+    if c.exprCallCallee != nil and c.exprCallCallee.kind == ekMacroTt and
+       c.exprCallCallee.exprMacroTtInner != nil and
+       c.exprCallCallee.exprMacroTtInner.kind == ekLiteral and
+       c.exprCallArgs.len == 2:
+      let opTok = c.exprCallCallee.exprMacroTtInner.exprLit
+      if opTok.kind.isBinaryPasteOp:
+        result = Expr(kind: ekBinary, loc: callLoc,
+          exprBinaryOp: opTok.kind,
+          exprBinaryLeft: c.exprCallArgs[0],
+          exprBinaryRight: c.exprCallArgs[1])
+        return
+    # Callee already unwrapped to op literal by value-position MacroTt splice
+    if c.exprCallCallee != nil and c.exprCallCallee.kind == ekLiteral and
+       c.exprCallArgs.len == 2 and c.exprCallCallee.exprLit.kind.isBinaryPasteOp:
+      result = Expr(kind: ekBinary, loc: callLoc,
+        exprBinaryOp: c.exprCallCallee.exprLit.kind,
+        exprBinaryLeft: c.exprCallArgs[0],
+        exprBinaryRight: c.exprCallArgs[1])
+      return
   of ekIndex:
     c.exprIndexObj = substExpr(c.exprIndexObj, env, callLoc)
     c.exprIndexIdx = substExpr(c.exprIndexIdx, env, callLoc)
   of ekField:
     c.exprFieldObj = substExpr(c.exprFieldObj, env, callLoc)
   of ekStructInit:
+    var stas: seq[TypeExpr] = @[]
+    for ta in c.exprStructInitTypeArgs:
+      stas.add(substType(ta, env, callLoc))
+    c.exprStructInitTypeArgs = stas
     var fields: seq[tuple[name: string, value: Expr]] = @[]
     for f in c.exprStructInitFields:
       fields.add((f.name, substExpr(f.value, env, callLoc)))
@@ -1247,6 +1295,25 @@ proc expandOneCall(call: Expr, macros: Table[string, Decl],
       exprMacroTtInner: inner, exprMacroTtGroup: true)
     result = @[callee, group]
 
+  ## Operators-only juxta: single binary arg `1 + 2` matches
+  ## `$a:expr, $op:tt, $b:expr` (or juxta without commas).
+  proc juxtaBinarySplit(rule: MacroRule, inArgs: seq[Expr]): seq[Expr] =
+    result = inArgs
+    if inArgs.len != 1 or inArgs[0] == nil: return
+    if inArgs[0].kind != ekBinary: return
+    if rule.frags.len != 3: return
+    if rule.frags[0].isRep or rule.frags[1].isRep or rule.frags[2].isRep: return
+    let k0 = if rule.frags[0].kinds.len > 0: rule.frags[0].kinds[0] else: rule.frags[0].kind
+    let k1 = if rule.frags[1].kinds.len > 0: rule.frags[1].kinds[0] else: rule.frags[1].kind
+    let k2 = if rule.frags[2].kinds.len > 0: rule.frags[2].kinds[0] else: rule.frags[2].kind
+    if k0 != mfkExpr or k1 != mfkTt or k2 != mfkExpr: return
+    if not inArgs[0].exprBinaryOp.isBinaryPasteOp: return
+    let opTok = Token(kind: inArgs[0].exprBinaryOp, text: "", loc: inArgs[0].loc)
+    let lit = Expr(kind: ekLiteral, loc: inArgs[0].loc, exprLit: opTok)
+    let opTt = Expr(kind: ekMacroTt, loc: inArgs[0].loc,
+      exprMacroTtInner: lit, exprMacroTtGroup: false)
+    result = @[inArgs[0].exprBinaryLeft, opTt, inArgs[0].exprBinaryRight]
+
   var matched: MacroRule
   var env: MacroEnv
   var found = false
@@ -1257,7 +1324,8 @@ proc expandOneCall(call: Expr, macros: Table[string, Decl],
     var gi = 0
     var ai = 0
     let useGroups = nReps > 1 and groups.len > 1
-    let flat = juxtaCallSplit(rule, args)
+    var flat = juxtaCallSplit(rule, args)
+    flat = juxtaBinarySplit(rule, flat)
 
     for frag in rule.frags:
       if failed: break

bootstrap/parser.nim

@@ -434,10 +434,22 @@ proc isMacroStmtStart(p: Parser): bool =
   p.peek() in {tkLet, tkVar, tkIf, tkWhile, tkFor, tkLoop, tkMatch, tkReturn,
                tkBreak, tkContinue, tkDefer, tkSwitch, tkDo}
 
+proc isBinaryPasteOpToken(k: TokenKind): bool =
+  ## Same set as macroexpand.isBinaryPasteOp — kept local to avoid cycles.
+  case k
+  of tkPlus, tkMinus, tkStar, tkSlash, tkPercent, tkStarStar,
+     tkAmp, tkPipe, tkCaret, tkShl, tkShr,
+     tkAmpAmp, tkPipePipe,
+     tkEq, tkNe, tkLt, tkLe, tkGt, tkGe:
+    true
+  else:
+    false
+
 proc parseMacroArg(p: var Parser): Expr =
   ## Macro call argument:
   ## - statement keywords → ekMacroStmt
   ## - `_` / pattern-only starts → ekMacroPat (also `$p:pat` from expr via coerce)
+  ## - bare binary operators (`+`, `*`, `==`, …) → ekMacroTt (operators-only paste)
   ## - else expression
   let loc = p.currentLoc
   if p.isMacroStmtStart():
@@ -447,6 +459,20 @@ proc parseMacroArg(p: var Parser): Expr =
   if p.check(tkUnderscore):
     let pat = p.parsePattern()
     return Expr(kind: ekMacroPat, loc: loc, exprMacroPat: pat)
+  # Operators-only tt: `apply_op!(+, 1, 2)` / `apply_op!(*, 2, 3)`.
+  # Bare ops are not primary exprs. Unary-capable tokens (`*`, `-`, …) are only
+  # claimed when the next token ends the arg (`,`, `)`, `;`) so `*int` still
+  # parses as a type/expr and juxta `a * b` still works as ekBinary.
+  let pk = p.peek()
+  if isBinaryPasteOpToken(pk):
+    let nxt = p.peek(1)
+    let endsArg = nxt in {tkComma, tkRParen, tkSemicolon, tkEndOfFile, tkNewLine}
+    let unaryCapable = pk in {tkStar, tkMinus, tkBang, tkAmp, tkTilde,
+                              tkPlusPlus, tkMinusMinus}
+    if endsArg or not unaryCapable:
+      let tok = p.advance()
+      let lit = Expr(kind: ekLiteral, loc: loc, exprLit: tok)
+      return Expr(kind: ekMacroTt, loc: loc, exprMacroTtInner: lit, exprMacroTtGroup: false)
   p.parseExpr()
 
 proc parseMacroRepExpr(p: var Parser): Expr =

bootstrap/sema.nim

@@ -1078,6 +1078,58 @@ proc collectGlobals*(sema: var Sema) =
 proc checkExpr*(sema: var Sema, expr: Expr, scope: Scope): Type
 proc checkStmt(sema: var Sema, stmt: Stmt, scope: Scope): Type
 
+proc isResultOrOptionName(name: string): bool =
+  name == "Result" or name.startsWith("Result_") or
+  name == "Option" or name.startsWith("Option_")
+
+proc extractResultOptionPayload*(sema: var Sema, opTy: Type, loc: SourceLocation, opKind: string): Type =
+  ## Payload type of `Result`/`Option` for `?` (try) and `!` (unwrap).
+  ## Prefer type-args (`Result<T,E>` → T); fall back to Ok/Some field on the enum decl.
+  if opTy == nil or opTy.isUnknown:
+    return makeUnknown()
+  if opTy.kind != tkNamed:
+    sema.emitError(loc, opKind & " requires Result or Option operand")
+    return makeUnknown()
+  let name = opTy.name
+  if not isResultOrOptionName(name):
+    sema.emitError(loc, opKind & " requires Result or Option, got " & opTy.toString)
+    return makeUnknown()
+  # Result<T,E> / Option<T> store payload in .inner
+  if opTy.inner.len >= 1:
+    return opTy.inner[0]
+  # Bare / monomorphized name: look up Ok(T) / Some(T) on the enum decl
+  var enumSym = sema.globalScope.lookup(name)
+  if (enumSym == nil or enumSym.decl == nil or enumSym.decl.kind != dkEnum):
+    if name.startsWith("Result_"):
+      enumSym = sema.globalScope.lookup("Result")
+    elif name.startsWith("Option_"):
+      enumSym = sema.globalScope.lookup("Option")
+  let wantVariant =
+    if name == "Option" or name.startsWith("Option_"): "Some"
+    else: "Ok"
+  if enumSym != nil and enumSym.decl != nil and enumSym.decl.kind == dkEnum:
+    var subst = initTable[string, Type]()
+    # Result_String_String → try to bind type params from mangled suffix when possible
+    if opTy.inner.len == 0 and enumSym.decl.declEnumTypeParams.len > 0 and
+       (name.startsWith("Result_") or name.startsWith("Option_")):
+      let prefix = if name.startsWith("Result_"): "Result_" else: "Option_"
+      let rest = name[prefix.len .. ^1]
+      # Split on '_' is imperfect for nested types; for simple T_E it works
+      let parts = rest.split('_')
+      var pi = 0
+      for tp in enumSym.decl.declEnumTypeParams:
+        if pi < parts.len and parts[pi].len > 0:
+          # Re-resolve simple type names (int, String, …)
+          let te = TypeExpr(kind: tekNamed, typeName: parts[pi])
+          subst[tp.name] = sema.resolveType(te)
+        inc pi
+    for variant in enumSym.decl.declEnumVariants:
+      if variant.name == wantVariant and variant.fields.len > 0:
+        let raw = sema.resolveType(variant.fields[0])
+        return sema.substituteTypeInType(raw, subst)
+  # Unknown payload — don't invent int (breaks String Results)
+  return makeUnknown()
+
 proc typeImplements(sema: Sema, t: Type, interfaceName: string): bool =
   ## Check if a type implements an interface by verifying all required methods exist.
   if t.isUnknown: return true
@@ -1838,14 +1890,12 @@ proc checkExpr*(sema: var Sema, expr: Expr, scope: Scope): Type =
     discard sema.checkExpr(expr.exprIsOperand, scope)
     return makeBool()
   of ekTry:
-    discard sema.checkExpr(expr.exprTryOperand, scope)
+    let opTy = sema.checkExpr(expr.exprTryOperand, scope)
-    # For now, assume Result<int, String> -> int
+    # Payload of Result/Option; validates operand is Result or Option
-    # TODO: check operand is Result/Option and current function returns same type
+    return sema.extractResultOptionPayload(opTy, expr.loc, "try operator (`?`)")
-    return makeInt()
   of ekUnwrap:
-    discard sema.checkExpr(expr.exprUnwrapOperand, scope)
+    let opTy = sema.checkExpr(expr.exprUnwrapOperand, scope)
-    # Unwrap: extract Ok value or panic on Err
+    return sema.extractResultOptionPayload(opTy, expr.loc, "unwrap operator (`!`)")
-    return makeInt()
   of ekBlock:
     var blockScope = newScope(scope)
     var lastType = makeVoid()

docs/BuildAndTest.md

@@ -181,13 +181,25 @@ no-libc freestanding firmware.
 | Thin runtime (no pthread/OpenSSL) | ✅ | `rt/runtime_minimal.c` |
 | Static musl / distroless | ✅ | `make test-musl-static`, Dockerfiles |
 | Linux multi-arch cross | ✅ | aarch64 + riscv64 smokes (SKIP without gcc) |
-| True freestanding (`-ffreestanding`, no libc) | 🔬 spike | Needs custom alloc, panic, and I/O stubs |
+| True freestanding (`-ffreestanding`, no libc) | ✅ spike shipped | `rt/runtime_freestanding.c` + `BUX_RUNTIME=freestanding` |
-| Cortex-M / qemu-system | 🔬 spike | Same; plus linker scripts and startup |
+| Cortex-M / qemu-system | 🔬 research | Needs linker scripts, startup, board UART — not in tree |
 
-**Practical path today:** build with `BUX_RUNTIME=minimal --static --target …` for
+**Freestanding runtime** (`rt/runtime_freestanding.c`):
-Linux userspace on foreign ISAs; treat bare-metal as a research project that
+
-starts from a custom `runtime_freestanding.c` (not shipped) and does **not**
+- No hosted libc: bump heap (default 256 KiB), freestanding string/arith helpers
-import `Std::Net` / `Std::Task` / OpenSSL.
+- Weak hooks `bux_fs_write` / `bux_fs_halt` for board BSP or host overrides
+- Net / Task / TLS / FS return failure stubs
+- Optional `_start` when compiled with `-DBUX_FS_PROVIDE_START` (nostdlib experiments)
+
+```bash
+make test-freestanding          # -ffreestanding -c + package build exit 42
+BUX_RUNTIME=freestanding buxc build .
+# Still uses host crt0 unless you pass -nostdlib / custom start via BUX_CFLAGS
+```
+
+**Practical path for cloud/cross:** `BUX_RUNTIME=minimal --static --target …` for
+Linux userspace. Use `freestanding` only for no-libc research; do **not** import
+`Std::Net` / `Std::Task` / OpenSSL on that path.
 
 ---
 

docs/IMPROVEMENTS.md

@@ -1,7 +1,32 @@
 # Bux — План за подобрения (post-v1.0.0)
 
 > **Дата:** 2026-07-28  
-> **Статус:** Всички приоритетни задачи изпълнени ✅
+> **Статус:** Всички приоритетни задачи изпълнени ✅ · follow-up DX/correctness shipped
+
+---
+
+## Сесия 4 — Try payload type + LSP formatting (2026-07-28)
+
+| # | Задача | Файлове |
+|---|--------|---------|
+| F.5 | `?` / `!` вече връщат **Ok/Some payload type** (не винаги `int`) | `bootstrap/sema.nim`, `bootstrap/hir_lower.nim` |
+| F.6 | Example `try_generic` — `Result<String, String>` + `?` | `examples/try_generic.bux` |
+| D.6 | LSP **v0.18** `textDocument/formatting` (+ range) = `bux fmt` | `tools/lsp_server.nim`, `tools/smoke_lsp_formatting.sh` |
+| D.7 | VS Code format-on-save default; docs | `vscode/package.json`, `docs/LSP.md` |
+
+**Verified:** `try_generic` prints `hello` / `empty name`; `try_operator` still OK; formatting smoke PASS.
+
+## Сесия 5 — Post-1.0 backlog: macros + freestanding (2026-07-28)
+
+| # | Задача | Файлове |
+|---|--------|---------|
+| M.1 | Generics in `$t:type` + `$t` in `Array_New<$t>` | `bootstrap/macroexpand.nim`, `src/macroexpand.bux` |
+| M.2 | Operators-only `:tt` paste (`$op($a,$b)` + juxta binary split) | `bootstrap/parser.nim`, `bootstrap/macroexpand.nim` |
+| M.3 | Examples `macro_type_generic`, `macro_op_paste` | `examples/` |
+| R.1 | `rt/runtime_freestanding.c` + `BUX_RUNTIME=freestanding` | `rt/`, `bootstrap/cli.nim`, `src/cli.bux` |
+| R.2 | `make test-freestanding` smoke | `tools/smoke_freestanding.sh` |
+
+**Verified:** both macro examples PASS; freestanding `-ffreestanding -c` + package exit 42.
 
 ---
 

docs/LSP.md

@@ -1,13 +1,14 @@
 # Bux Language Server (`bux-lsp`)
 
-> **Status:** **v0.17.0** — stdio JSON-RPC 2.0 language server  
+> **Status:** **v0.18.0** — stdio JSON-RPC 2.0 language server  
 > **Binary:** `tools/bux-lsp` (`make lsp`)  
 > **Editors:** VS Code extension in [`vscode/`](../vscode/README.md); any LSP client via stdio
 
 Bux already ships a real Language Server Protocol implementation. It is **not**
 syntax-only: hover and outline use bootstrap semantic analysis when available,
-and **error underlines (red squiggles)** come from **in-process** lex / parse / type-check
+**error underlines (red squiggles)** come from **in-process** lex / parse / type-check
-of the **live editor buffer** on every open, edit, and save.
+of the **live editor buffer** on every open, edit, and save, and **Format Document**
+uses the same indentation engine as `bux fmt`.
 
 ---
 
@@ -33,13 +34,15 @@ Protocol framing: standard `Content-Length` headers + JSON-RPC 2.0 body.
 
 ---
 
-## Capabilities (v0.16)
+## Capabilities (v0.18)
 
 | Method | Support | Notes |
 |--------|---------|--------|
-| `initialize` / `shutdown` / `exit` | ✅ | `serverInfo`: `bux-lsp` 0.17.0 |
+| `initialize` / `shutdown` / `exit` | ✅ | `serverInfo`: `bux-lsp` 0.18.0 |
 | `textDocument/didOpen` / `didChange` / `didSave` | ✅ | Full text sync (`textDocumentSync: 1`) |
 | `textDocument/publishDiagnostics` | ✅ | **Live underlines** on open/change/save (in-process); optional `buxc` merge on open/save |
+| `textDocument/formatting` | ✅ | Full document — same rules as `bux fmt` (4-space brace indent) |
+| `textDocument/rangeFormatting` | ✅ | Applies full-file format (indent depends on whole brace structure) |
 | `textDocument/completion` | ✅ | Trigger: `.` `:` |
 | `textDocument/hover` | ✅ | Sema types for globals/stdlib; **scoped locals** + inferred `let` |
 | `textDocument/definition` | ✅ | Go to definition |
@@ -123,15 +126,28 @@ make test-lsp
 
 ---
 
+## Format Document / format-on-save
+
+`textDocument/formatting` re-indents the buffer with **4 spaces × brace depth**
+(identical to `bux fmt` / `bootstrap/fmt.nim`). Idempotent: a clean file yields
+an empty edit list.
+
+**VS Code:** the extension defaults `editor.formatOnSave` for `[bux]`. Disable
+with `"editor.formatOnSave": false` in workspace settings if you prefer manual
+only. Command palette: **Format Document**.
+
+```bash
+make test-lsp                 # includes tools/smoke_lsp_formatting.sh
+```
+
 ## Limitations / not yet
 
 Honest gaps (so Reddit / issue trackers stay accurate):
 
-- **No format-on-save via LSP** yet (`bux fmt` exists as CLI; not `textDocument/formatting`)
 - **No semantic tokens** provider (TextMate grammar handles highlighting in VS Code)
 - **No code actions / lightbulbs** (quick-fixes)
 - **No inlay hints**
-- **didChange** uses a fast symbol path; full sema + diagnostics refresh mainly on open/save
+- **rangeFormatting** reformats the whole file (partial selection cannot get correct indent without full brace context)
 - Completion is useful but not a full IDE IntelliSense engine
 - Single-process stdio only (no TCP/socket mode)
 

docs/LanguageRef.md

@@ -997,6 +997,25 @@ func Compute() -> Result {
 ```
 
 `?` can be used on `Result` and `Option` types in any expression context.
+The type of `expr?` is the **Ok / Some payload** (`T` in `Result<T,E>` or
+`Option<T>`), not always `int`. The enclosing function must return a compatible
+Result/Option so Err/None can propagate.
+
+```bux
+// Generic Result — payload type is String
+func GetName() -> Result<String, String> {
+    return Result_NewOk<String, String>("bux");
+}
+func Run() -> Result<String, String> {
+    let n: String = GetName()?;  // n: String
+    return Result_NewOk<String, String>(n);
+}
+```
+
+The postfix unwrap operator `expr!` extracts Ok/Some or panics (and exits) on
+Err/None; its type is likewise the payload type.
+
+See also `examples/try_operator.bux` and `examples/try_generic.bux`.
 
 ---
 
@@ -1312,13 +1331,32 @@ macro! with_acc {
   between fragments) matches a **single call-site argument** that is a call
   expression: `apply_juxta!(Add(2, 5))` → binds `$f=Add`, `$args` = arg-list
   group, then `$f($args)` flattens to `Add(2, 5)`.
-- **Type fragments (session 87):**
+- **Type fragments (session 87+):** named, pointer, and **generic** types
+  (`Array<int>`, `*int`); `$t` substitutes in `sizeof` / cast / let types and
+  monomorph call type args (`Array_New<$t>`).
   ```bux
   macro! size_of {
       ( $t:type ) => { sizeof($t) as int }
   }
+  macro! new_array {
+      ( $t:type, $cap:expr ) => { Array_New<$t>($cap) }
+  }
   let n: int = size_of!(int);
   let p: int = size_of!(*int);
+  let s: int = size_of!(Array<int>);
+  var a: Array<int> = new_array!(int, 4);
+  ```
+- **Operators-only `:tt` paste:**
+  ```bux
+  macro! apply_op {
+      ( $op:tt, $a:expr, $b:expr ) => { $op($a, $b) }
+  }
+  macro! flip_op {
+      ( $a:expr, $op:tt, $b:expr ) => { $op($b, $a) }
+  }
+  let x: int = apply_op!(+, 3, 4);   // 7
+  let y: int = apply_op!(*, 6, 7);   // 42
+  let z: int = flip_op!(10 - 3);     // -7  (juxta binary split)
   ```
 
 ### Invocation
@@ -1415,8 +1453,15 @@ Examples: `examples/macro_hygiene.bux`, `examples/macro_unhygienic.bux`.
   templates (not as a free-standing primary expression).
 - Raw delimiter-balanced `tt` covers **tuple** `(a, b)` and **slice lit**
   `[a, b]` groups, plus **juxta call-split** for `$f:ident $args:tt` matching
-  `F(a, b)`. Arbitrary free-form token pastes (operators-only, type-only
+  `F(a, b)`.
-  without AST) remain out of scope.
+- **Operators-only paste:** bare binary ops as `:tt` (`+`, `*`, `==`, …) and
+  juxta binary split `$a:expr $op:tt $b:expr` on a single binary arg. Template
+  form `$op($a, $b)` rebuilds `a OP b`. See `examples/macro_op_paste.bux`.
+- **`:type` generics:** `Array<int>`, `*int`, nested type args; `$t` splices
+  into `sizeof($t)`, casts, and `Array_New<$t>(…)`. See
+  `examples/macro_type.bux`, `examples/macro_type_generic.bux`.
+- Fully free-form token streams (unparsed soup) remain out of scope.
 
 Examples: `examples/macro_tt.bux`, `examples/macro_tt_raw.bux`,
-`examples/macro_repeat.bux`, `examples/macro_nested.bux`.
+`examples/macro_repeat.bux`, `examples/macro_nested.bux`,
+`examples/macro_type_generic.bux`, `examples/macro_op_paste.bux`.

docs/QUALITY_PLAN.md

@@ -1472,10 +1472,22 @@ bootstrap + **buxc2** `macro_tt_raw` (incl. slice) PASS.
 5. Tag `v1.0.0` after `make test` gate
 
 **Post-1.0 backlog (MINOR, not freeze blockers):**
-- Generics in `:type` (`Array<int>`); operators-only tt paste
+- ~~Generics in `:type` (`Array<int>`); operators-only tt paste~~ ✅ session 5
-- `runtime_freestanding.c` + Cortex-M research
+- ~~`runtime_freestanding.c`~~ ✅ session 5 (Cortex-M / board BSP still research)
 - LSP / IDE versioning independent of language MAJOR
 
+### Follow-up (2026-07-28)
+
+1. **`?` / `!` payload types** — bootstrap no longer hardcodes `int`; Ok/Some type
+   from `Result<T,E>` / enum fields (`bootstrap/sema.nim`, `hir_lower.nim`).
+2. **Example** `try_generic` — String Result propagation.
+3. **LSP 0.18** — `textDocument/formatting` (+ range) via `formatSource` / `bux fmt`;
+   VS Code format-on-save default; `tools/smoke_lsp_formatting.sh`.
+4. **Macros:** generic `:type` + `Array_New<$t>`; operators-only `$op($a,$b)` /
+   juxta binary split (`examples/macro_type_generic`, `macro_op_paste`).
+5. **Freestanding:** `rt/runtime_freestanding.c`, `BUX_RUNTIME=freestanding`,
+   `make test-freestanding`.
+
 ### Изрично **не** правим
 
 - Повече Windows examples / Win OpenSSL / Win sockets

examples/macro_op_paste.bux

@@ -0,0 +1,40 @@
+// Operators-only `:tt` paste — `$op($a, $b)` → `a OP b`
+import Std::Io::{PrintLine, PrintInt};
+import Std::Test::{Test_AssertEqInt, Test_AssertEqBool, Test_Pass};
+
+// Explicit op as call-site tt: apply_op!(+, 3, 4) → 7
+macro! apply_op {
+    ( $op:tt, $a:expr, $b:expr ) => { $op($a, $b) }
+}
+
+// Juxta binary split: flip_op!(10 - 3) → 3 - 10
+macro! flip_op {
+    ( $a:expr, $op:tt, $b:expr ) => { $op($b, $a) }
+}
+
+func Main() -> int {
+    let sum: int = apply_op!(+, 3, 4);
+    Test_AssertEqInt(sum, 7);
+
+    let prod: int = apply_op!(*, 6, 7);
+    Test_AssertEqInt(prod, 42);
+
+    let diff: int = flip_op!(10 - 3);
+    Test_AssertEqInt(diff, -7);
+
+    let eq: bool = apply_op!(==, 5, 5);
+    Test_AssertEqBool(eq, true);
+
+    let lt: bool = apply_op!(<, 2, 9);
+    Test_AssertEqBool(lt, true);
+
+    PrintInt(sum);
+    PrintLine("");
+    PrintInt(prod);
+    PrintLine("");
+    PrintInt(diff);
+    PrintLine("");
+    PrintLine("PASS macro_op_paste");
+    Test_Pass("macro_op_paste");
+    return 0;
+}

examples/macro_type_generic.bux

@@ -0,0 +1,44 @@
+// Generics in `$t:type` + type-arg splice into Array_New<$t>
+import Std::Io::{PrintLine, PrintInt};
+import Std::Array::{Array, Array_New, Array_Push, Array_Get, Array_Len, Array_Free};
+import Std::Test::{Test_AssertEqInt, Test_Pass};
+
+macro! size_of {
+    ( $t:type ) => { sizeof($t) as int }
+}
+
+macro! new_array {
+    ( $t:type, $cap:expr ) => {
+        Array_New<$t>($cap)
+    }
+}
+
+func Main() -> int {
+    // Generic type fragment: Array<int>
+    let sz: int = size_of!(Array<int>);
+    PrintInt(sz);
+    PrintLine("");
+    if sz < 8 {
+        PrintLine("FAIL size_of Array<int>");
+        return 1;
+    }
+
+    // $t spliced into monomorphized call Array_New<$t>
+    var a: Array<int> = new_array!(int, 4);
+    Array_Push<int>(&a, 10);
+    Array_Push<int>(&a, 20);
+    Test_AssertEqInt(Array_Get<int>(&a, 0), 10);
+    Test_AssertEqInt(Array_Get<int>(&a, 1), 20);
+    Test_AssertEqInt(Array_Len<int>(&a) as int, 2);
+    Array_Free<int>(&a);
+
+    let psz: int = size_of!(*int);
+    if psz != 4 && psz != 8 {
+        PrintLine("FAIL size_of *int");
+        return 1;
+    }
+
+    PrintLine("PASS macro_type_generic");
+    Test_Pass("macro_type_generic");
+    return 0;
+}

examples/try_generic.bux

@@ -0,0 +1,32 @@
+// Try operator `?` with generic Result<T,E> (non-int Ok payload).
+import Std::Io::{PrintLine};
+import Std::Result::{Result, Result_NewOk, Result_NewErr};
+import Std::String::{String_Eq};
+
+func GetGreeting(name: String) -> Result<String, String> {
+    if String_Eq(name, "") {
+        return Result_NewErr<String, String>("empty name");
+    }
+    return Result_NewOk<String, String>("hello");
+}
+
+func Greet(name: String) -> Result<String, String> {
+    let g: String = GetGreeting(name)?;
+    return Result_NewOk<String, String>(g);
+}
+
+func Main() -> int {
+    PrintLine("Try generic Result demo:");
+
+    let ok: Result<String, String> = Greet("bux");
+    if ok.tag == Result_Ok {
+        PrintLine(ok.data.Ok_0);
+    }
+
+    let err: Result<String, String> = Greet("");
+    if err.tag == Result_Err {
+        PrintLine(err.data.Err_0);
+    }
+
+    return 0;
+}

rt/runtime_freestanding.c

@@ -0,0 +1,484 @@
+/* Bux Runtime — freestanding / bare-metal research spike (post-v1.0)
+ *
+ * Goal: link with `-ffreestanding -nostdlib` without pulling in a hosted libc.
+ * This is **not** a full embedded platform kit (no Cortex-M startup, no
+ * linker scripts, no UART drivers). It is a portable base for:
+ *   - compile smoke under -ffreestanding
+ *   - no-libc static link experiments (custom `_start`)
+ *   - future board BSPs that replace the weak I/O hooks
+ *
+ * Select: BUX_RUNTIME=freestanding  (bootstrap + selfhost)
+ *
+ * Memory: fixed bump allocator over a static arena (default 256 KiB).
+ * Override at compile time: -DBUX_FS_HEAP_BYTES=N
+ *
+ * I/O: weak stubs — default print is a no-op; panic spins. Host may override:
+ *   void bux_fs_write(const char* s, unsigned n);
+ *   void bux_fs_halt(int code);
+ */
+
+#if defined(__STDC_HOSTED__) && __STDC_HOSTED__ == 1 && !defined(BUX_FS_FORCE)
+/* When accidentally compiled as hosted without -ffreestanding, still avoid
+ * libc — we implement everything we need. */
+#endif
+
+/* ── Fixed-width types without stdint.h ────────────────────────────────── */
+typedef signed char        bux_i8;
+typedef unsigned char      bux_u8;
+typedef short              bux_i16;
+typedef unsigned short     bux_u16;
+typedef int                bux_i32;
+typedef unsigned int       bux_u32;
+#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(__aarch64__)
+typedef long               bux_i64;
+typedef unsigned long      bux_u64;
+typedef unsigned long      bux_size;
+#else
+typedef long long          bux_i64;
+typedef unsigned long long bux_u64;
+typedef unsigned int       bux_size;
+#endif
+typedef bux_u8             bux_bool;
+#ifndef NULL
+#  define NULL ((void*)0)
+#endif
+#ifndef true
+#  define true 1
+#  define false 0
+#endif
+
+/* ── Heap ─────────────────────────────────────────────────────────────── */
+#ifndef BUX_FS_HEAP_BYTES
+#  define BUX_FS_HEAP_BYTES (256u * 1024u)
+#endif
+
+static unsigned char bux_fs_heap[BUX_FS_HEAP_BYTES];
+static bux_size bux_fs_heap_off = 0;
+
+/* Weak hooks — board / host may override */
+__attribute__((weak)) void bux_fs_write(const char* s, unsigned n) {
+    (void)s; (void)n;
+}
+__attribute__((weak)) void bux_fs_halt(int code) {
+    (void)code;
+    for (;;) { /* spin */ }
+}
+
+/* ── CLI args (empty under freestanding) ──────────────────────────────── */
+int g_argc = 0;
+char** g_argv = NULL;
+
+int bux_argc(void) { return g_argc; }
+char* bux_argv(int index) {
+    (void)index;
+    return (char*)"";
+}
+
+/* ── Memory ───────────────────────────────────────────────────────────── */
+static void bux_fs_zero(void* p, bux_size n) {
+    unsigned char* b = (unsigned char*)p;
+    bux_size i;
+    for (i = 0; i < n; i++) b[i] = 0;
+}
+
+void* bux_alloc(bux_size size) {
+    /* 8-byte align */
+    bux_size off = (bux_fs_heap_off + 7u) & ~(bux_size)7u;
+    if (size == 0) size = 1;
+    if (off + size > (bux_size)BUX_FS_HEAP_BYTES) {
+        bux_fs_write("OOM\n", 4);
+        bux_fs_halt(1);
+        return NULL;
+    }
+    void* p = &bux_fs_heap[off];
+    bux_fs_heap_off = off + size;
+    bux_fs_zero(p, size);
+    return p;
+}
+
+void* bux_realloc(void* ptr, bux_size size) {
+    /* Bump allocator cannot free — allocate fresh + copy if needed */
+    void* n = bux_alloc(size);
+    if (ptr != NULL && n != NULL && size > 0) {
+        unsigned char* d = (unsigned char*)n;
+        unsigned char* s = (unsigned char*)ptr;
+        bux_size i;
+        /* unknown old size — best effort copy of `size` bytes */
+        for (i = 0; i < size; i++) d[i] = s[i];
+    }
+    return n;
+}
+
+void bux_free(void* ptr) { (void)ptr; /* bump: no-op */ }
+
+/* ── Basic I/O / panic ────────────────────────────────────────────────── */
+void bux_print(const char* s) {
+    if (!s) return;
+    unsigned n = 0;
+    while (s[n]) n++;
+    bux_fs_write(s, n);
+}
+void bux_println(const char* s) {
+    bux_print(s ? s : "");
+    bux_fs_write("\n", 1);
+}
+void bux_print_int(bux_i64 n) {
+    char buf[32];
+    int i = 0;
+    int neg = 0;
+    if (n < 0) { neg = 1; n = -n; }
+    if (n == 0) { buf[i++] = '0'; }
+    else {
+        while (n > 0 && i < 30) {
+            buf[i++] = (char)('0' + (n % 10));
+            n /= 10;
+        }
+    }
+    if (neg) buf[i++] = '-';
+    /* reverse */
+    int a = 0, b = i - 1;
+    while (a < b) {
+        char t = buf[a]; buf[a] = buf[b]; buf[b] = t;
+        a++; b--;
+    }
+    bux_fs_write(buf, (unsigned)i);
+}
+void bux_print_float(double f) {
+    /* minimal: cast to int for freestanding */
+    bux_print_int((bux_i64)f);
+}
+void bux_print_bool(bux_bool b) { bux_print(b ? "true" : "false"); }
+void bux_print_char(char c) { bux_fs_write(&c, 1); }
+void bux_panic(const char* msg) {
+    bux_fs_write("PANIC: ", 7);
+    if (msg) {
+        unsigned n = 0;
+        while (msg[n]) n++;
+        bux_fs_write(msg, n);
+    }
+    bux_fs_write("\n", 1);
+    bux_fs_halt(1);
+}
+void bux_exit(int code) { bux_fs_halt(code); }
+void bux_assert(int cond, const char* file, int line, const char* expr) {
+    (void)file; (void)line; (void)expr;
+    if (!cond) bux_panic("assert failed");
+}
+
+/* ── Checked arithmetic ───────────────────────────────────────────────── */
+bux_i64 bux_div_i64(bux_i64 a, bux_i64 b) {
+    if (b == 0) bux_panic("division by zero");
+    return a / b;
+}
+bux_i64 bux_mod_i64(bux_i64 a, bux_i64 b) {
+    if (b == 0) bux_panic("modulo by zero");
+    return a % b;
+}
+bux_i64 bux_add_i64_checked(bux_i64 a, bux_i64 b) { return a + b; }
+bux_i64 bux_sub_i64_checked(bux_i64 a, bux_i64 b) { return a - b; }
+bux_i64 bux_mul_i64_checked(bux_i64 a, bux_i64 b) { return a * b; }
+bux_i64 bux_neg_i64_checked(bux_i64 a) { return -a; }
+
+/* ── Strings (no libc) ────────────────────────────────────────────────── */
+unsigned int bux_strlen(const char* s) {
+    unsigned int n = 0;
+    if (!s) return 0;
+    while (s[n]) n++;
+    return n;
+}
+int bux_strlen_c(const char* s) { return (int)bux_strlen(s); }
+int bux_strcmp(const char* a, const char* b) {
+    if (!a) a = "";
+    if (!b) b = "";
+    while (*a && *a == *b) { a++; b++; }
+    return (unsigned char)*a - (unsigned char)*b;
+}
+int bux_strncmp(const char* a, const char* b, unsigned int n) {
+    if (!a) a = "";
+    if (!b) b = "";
+    unsigned int i;
+    for (i = 0; i < n; i++) {
+        if (a[i] != b[i] || a[i] == 0) return (unsigned char)a[i] - (unsigned char)b[i];
+    }
+    return 0;
+}
+char* bux_strcpy(char* dest, const char* src) {
+    if (!dest) return NULL;
+    if (!src) { dest[0] = 0; return dest; }
+    char* d = dest;
+    while ((*d++ = *src++)) {}
+    return dest;
+}
+char* bux_strcat(char* dest, const char* src) {
+    if (!dest) return NULL;
+    if (!src) return dest;
+    char* d = dest;
+    while (*d) d++;
+    while ((*d++ = *src++)) {}
+    return dest;
+}
+char* bux_strncpy(char* dest, const char* src, unsigned int n) {
+    if (!dest) return NULL;
+    unsigned int i = 0;
+    if (src) {
+        for (; i < n && src[i]; i++) dest[i] = src[i];
+    }
+    for (; i < n; i++) dest[i] = 0;
+    return dest;
+}
+double bux_str_to_float(const char* s) {
+    (void)s;
+    return 0.0;
+}
+bux_i64 bux_str_to_int(const char* s) {
+    if (!s) return 0;
+    bux_i64 v = 0;
+    int neg = 0;
+    if (*s == '-') { neg = 1; s++; }
+    while (*s >= '0' && *s <= '9') {
+        v = v * 10 + (*s - '0');
+        s++;
+    }
+    return neg ? -v : v;
+}
+const char* bux_strstr(const char* haystack, const char* needle) {
+    if (!haystack || !needle) return NULL;
+    if (!*needle) return haystack;
+    for (const char* h = haystack; *h; h++) {
+        const char* a = h;
+        const char* b = needle;
+        while (*a && *b && *a == *b) { a++; b++; }
+        if (!*b) return h;
+    }
+    return NULL;
+}
+unsigned int bux_str_offset(const char* pos, const char* base) {
+    if (!pos || !base) return 0;
+    return (unsigned int)(pos - base);
+}
+int bux_str_contains(const char* haystack, const char* needle) {
+    return bux_strstr(haystack, needle) != NULL;
+}
+int bux_str_is_null(const char* s) { return s == NULL; }
+
+char* bux_str_slice(const char* s, unsigned int start, unsigned int len) {
+    if (!s) s = "";
+    unsigned int sl = bux_strlen(s);
+    if (start > sl) start = sl;
+    if (start + len > sl) len = sl - start;
+    char* out = (char*)bux_alloc(len + 1);
+    unsigned int i;
+    for (i = 0; i < len; i++) out[i] = s[start + i];
+    out[len] = 0;
+    return out;
+}
+static int is_ws(char c) {
+    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+char* bux_str_trim_left(const char* s) {
+    if (!s) s = "";
+    while (*s && is_ws(*s)) s++;
+    return bux_str_slice(s, 0, bux_strlen(s));
+}
+char* bux_str_trim_right(const char* s) {
+    if (!s) s = "";
+    unsigned int n = bux_strlen(s);
+    while (n > 0 && is_ws(s[n - 1])) n--;
+    return bux_str_slice(s, 0, n);
+}
+char* bux_str_trim(const char* s) {
+    char* a = bux_str_trim_left(s);
+    return bux_str_trim_right(a);
+}
+char* bux_int_to_str(bux_i64 n) {
+    char buf[32];
+    int i = 0;
+    int neg = 0;
+    if (n < 0) { neg = 1; n = -n; }
+    if (n == 0) buf[i++] = '0';
+    else while (n > 0 && i < 30) { buf[i++] = (char)('0' + (n % 10)); n /= 10; }
+    if (neg) buf[i++] = '-';
+    int a = 0, b = i - 1;
+    while (a < b) { char t = buf[a]; buf[a] = buf[b]; buf[b] = t; a++; b--; }
+    buf[i] = 0;
+    return bux_str_slice(buf, 0, (unsigned)i);
+}
+char* bux_float_to_string(double f) { return bux_int_to_str((bux_i64)f); }
+
+unsigned int bux_str_split_count(const char* s, const char* delim) {
+    (void)s; (void)delim;
+    return 0;
+}
+char* bux_str_split_part(const char* s, const char* delim, unsigned int index) {
+    (void)s; (void)delim; (void)index;
+    return (char*)"";
+}
+char* bux_str_join2(const char* a, const char* b, const char* sep) {
+    unsigned int na = bux_strlen(a), nb = bux_strlen(b), ns = bux_strlen(sep);
+    char* out = (char*)bux_alloc(na + ns + nb + 1);
+    unsigned int i = 0, j;
+    for (j = 0; j < na; j++) out[i++] = a[j];
+    for (j = 0; j < ns; j++) out[i++] = sep[j];
+    for (j = 0; j < nb; j++) out[i++] = b[j];
+    out[i] = 0;
+    return out;
+}
+char* bux_str_format(const char* fmt, const char* a0, const char* a1, const char* a2, const char* a3) {
+    (void)a1; (void)a2; (void)a3;
+    /* minimal: return fmt or a0 */
+    if (a0 && a0[0]) return bux_str_slice(a0, 0, bux_strlen(a0));
+    if (fmt) return bux_str_slice(fmt, 0, bux_strlen(fmt));
+    return (char*)"";
+}
+char* bux_escape_c_string(const char* s, int len) {
+    (void)len;
+    return s ? bux_str_slice(s, 0, bux_strlen(s)) : (char*)"";
+}
+
+/* StringBuilder stubs (shape-compatible enough for unused mono) */
+typedef struct {
+    char* data;
+    unsigned int len;
+    unsigned int cap;
+} BuxStringBuilder;
+
+void bux_sb_append(BuxStringBuilder* sb, const char* s) {
+    (void)sb; (void)s;
+}
+void bux_sb_append_int(BuxStringBuilder* sb, bux_i64 n) { (void)sb; (void)n; }
+void bux_sb_append_float(BuxStringBuilder* sb, double f) { (void)sb; (void)f; }
+void bux_sb_append_char(BuxStringBuilder* sb, char c) { (void)sb; (void)c; }
+const char* bux_sb_build(BuxStringBuilder* sb) { return sb && sb->data ? sb->data : ""; }
+void bux_sb_free(BuxStringBuilder* sb) { (void)sb; }
+
+/* ── FS / path / OS — unavailable ─────────────────────────────────────── */
+char* bux_read_file(const char* path) { (void)path; return NULL; }
+int bux_write_file(const char* path, const char* content) {
+    (void)path; (void)content;
+    return -1;
+}
+int bux_file_exists(const char* path) { (void)path; return 0; }
+char* bux_path_join(const char* a, const char* b) {
+    return bux_str_join2(a ? a : "", b ? b : "", "/");
+}
+char* bux_path_parent(const char* path) {
+    (void)path;
+    return (char*)".";
+}
+char* bux_path_ext(const char* path) {
+    (void)path;
+    return (char*)"";
+}
+int bux_mkdir_if_needed(const char* path) { (void)path; return -1; }
+int bux_dir_exists(const char* path) { (void)path; return 0; }
+char** bux_list_dir(const char* dir, const char* ext, int* out_count) {
+    (void)dir; (void)ext;
+    if (out_count) *out_count = 0;
+    return NULL;
+}
+
+/* ── Math (integer only; float ops soft-stub) ─────────────────────────── */
+double bux_sqrt(double x) { return x; }
+double bux_pow(double x, double y) { (void)y; return x; }
+bux_i64 bux_abs_i64(bux_i64 x) { return x < 0 ? -x : x; }
+double bux_abs_f64(double x) { return x < 0 ? -x : x; }
+bux_i64 bux_min_i64(bux_i64 a, bux_i64 b) { return a < b ? a : b; }
+bux_i64 bux_max_i64(bux_i64 a, bux_i64 b) { return a > b ? a : b; }
+double bux_min_f64(double a, double b) { return a < b ? a : b; }
+double bux_max_f64(double a, double b) { return a > b ? a : b; }
+
+unsigned int bux_hash_bytes(const void* ptr, bux_size size) {
+    const unsigned char* p = (const unsigned char*)ptr;
+    unsigned int h = 2166136261u;
+    bux_size i;
+    if (!p) return 0;
+    for (i = 0; i < size; i++) {
+        h ^= p[i];
+        h *= 16777619u;
+    }
+    return h;
+}
+int bux_mem_eq(const void* a, const void* b, bux_size size) {
+    const unsigned char* x = (const unsigned char*)a;
+    const unsigned char* y = (const unsigned char*)b;
+    bux_size i;
+    if (!x || !y) return x == y;
+    for (i = 0; i < size; i++) if (x[i] != y[i]) return 0;
+    return 1;
+}
+unsigned int bux_hash_string(const char* s) {
+    return bux_hash_bytes(s, bux_strlen(s));
+}
+
+const char* bux_getenv(const char* name) { (void)name; return ""; }
+const char* bux_cc_ld_stable(void) { return ""; }
+int bux_setenv(const char* name, const char* value) {
+    (void)name; (void)value;
+    return -1;
+}
+const char* bux_getcwd(void) { return "."; }
+int bux_chdir(const char* path) { (void)path; return -1; }
+
+void bux_install_stop_handlers(void) {}
+int bux_should_stop(void) { return 0; }
+void bux_set_stop_listen_fd(int fd) { (void)fd; }
+
+bux_i64 bux_time_ms(void) { return 0; }
+bux_i64 bux_time_us(void) { return 0; }
+
+/* ── Task / net / crypto — hard stubs ─────────────────────────────────── */
+int bux_task_spawn(void* fn, void* arg) { (void)fn; (void)arg; return -1; }
+void bux_task_yield(void) {}
+void bux_task_sleep_ms(int ms) { (void)ms; }
+
+int bux_chan_new(int cap) { (void)cap; return -1; }
+int bux_chan_send(int id, void* msg) { (void)id; (void)msg; return -1; }
+void* bux_chan_recv(int id) { (void)id; return NULL; }
+void bux_chan_close(int id) { (void)id; }
+
+int bux_tcp_listen(int port) { (void)port; return -1; }
+int bux_tcp_accept(int fd) { (void)fd; return -1; }
+int bux_tcp_connect(const char* host, int port) {
+    (void)host; (void)port;
+    return -1;
+}
+int bux_tcp_send(int fd, const void* buf, int n) {
+    (void)fd; (void)buf; (void)n;
+    return -1;
+}
+int bux_tcp_recv(int fd, void* buf, int n) {
+    (void)fd; (void)buf; (void)n;
+    return -1;
+}
+void bux_tcp_close(int fd) { (void)fd; }
+
+void* bux_tls_server_ctx(const char* cert, const char* key) {
+    (void)cert; (void)key;
+    return NULL;
+}
+void* bux_tls_server_ctx_ex(const char* cert, const char* key, const char* ca) {
+    (void)cert; (void)key; (void)ca;
+    return NULL;
+}
+int bux_tls_accept(void* ctx, int fd) { (void)ctx; (void)fd; return -1; }
+int bux_tls_send(int h, const void* buf, int n) {
+    (void)h; (void)buf; (void)n;
+    return -1;
+}
+int bux_tls_recv(int h, void* buf, int n) {
+    (void)h; (void)buf; (void)n;
+    return -1;
+}
+void bux_tls_close(int h) { (void)h; }
+const char* bux_tls_error(void) { return "tls unavailable (freestanding)"; }
+
+/* ── Optional bare `_start` for -nostdlib link experiments ───────────── */
+#ifdef BUX_FS_PROVIDE_START
+extern int main(int argc, char** argv);
+void _start(void) {
+    g_argc = 0;
+    g_argv = NULL;
+    int code = main(0, NULL);
+    bux_fs_halt(code);
+}
+#endif

src/cli.bux

@@ -59,10 +59,13 @@ module Cli {
                 return "rt/runtime_win.c";
             }
             if String_Eq(env, "minimal") || String_Eq(env, "thin") ||
-            String_Eq(env, "embed") || String_Eq(env, "embedded") ||
+            String_Eq(env, "embed") || String_Eq(env, "embedded") {
-            String_Eq(env, "freestanding") {
                 return "rt/runtime_minimal.c";
             }
+            if String_Eq(env, "freestanding") || String_Eq(env, "bare") ||
+            String_Eq(env, "nolibc") {
+                return "rt/runtime_freestanding.c";
+            }
             if String_Eq(env, "full") || String_Eq(env, "posix") {
                 return "rt/runtime.c";
             }
@@ -78,6 +81,7 @@ module Cli {
 
     func Cli_IsThinRuntimePath(rtPath: String) -> bool {
         if String_Contains(rtPath, "runtime_minimal.c") { return true; }
+        if String_Contains(rtPath, "runtime_freestanding.c") { return true; }
         if String_Contains(rtPath, "runtime_win.c") { return true; }
         return false;
     }

src/macroexpand.bux

@@ -470,16 +470,30 @@ module MacroExpand {
             (aexp.kind == ekSlice && aexp.callArgCount > 0);
             return wrap;
         }
-        // type — session 87: named / pointer type from call-site expr shape
+        // type — session 87+: named / pointer / generic Array<int> from call-site
         if String_Eq(kindStr, "type") {
             if aexp.kind == ekMacroType { return aexp; }
             var te: *TypeExpr = null as *TypeExpr;
-            if aexp.kind == ekIdent {
+            if aexp.kind == ekIdent || aexp.kind == ekGenericCall {
                 te = bux_alloc(sizeof(TypeExpr)) as *TypeExpr;
                 te.kind = tekNamed;
                 te.line = aexp.line;
                 te.column = aexp.column;
+                if aexp.kind == ekGenericCall && !String_Eq(aexp.genericCallee, "") {
+                    te.typeName = aexp.genericCallee;
+                } else {
                     te.typeName = aexp.strValue;
+                }
+                // Generic type args: Array<int> / Map<K,V> (selfhost: up to 2 string args)
+                var gcount: int = aexp.genericTypeArgCount;
+                if gcount > 0 {
+                    te.typeArgName0 = aexp.genericTypeArg0;
+                    te.typeArgCount = 1;
+                    if gcount > 1 {
+                        te.typeArgName1 = aexp.genericTypeArg1;
+                        te.typeArgCount = 2;
+                    }
+                }
             } else if aexp.kind == ekUnary && aexp.intValue == tkStar && aexp.child1 != null as *Expr {
                 // *T from unary star
                 let inner: *Expr = Macro_CoerceArg("type", aexp.child1);
@@ -518,6 +532,35 @@ module MacroExpand {
                 return bound.refType;
             }
         }
+        // Array<$t> / Map<$k,$v> — substitute type-arg name slots
+        if te.kind == tekNamed && te.typeArgCount > 0 {
+            if String_StartsWith(te.typeArgName0, "$") {
+                let b0: *Expr = Env_Lookup(env, te.typeArgName0);
+                if b0 != null as *Expr && b0.kind == ekMacroType && b0.refType != null as *TypeExpr {
+                    // Flatten simple named type arg (int, String, …)
+                    if b0.refType.kind == tekNamed && b0.refType.typeArgCount == 0 {
+                        te.typeArgName0 = b0.refType.typeName;
+                    } else if b0.refType.kind == tekNamed {
+                        // Nested generic: store mangled-ish "Array_int" for mono
+                        te.typeArgName0 = b0.refType.typeName;
+                        if b0.refType.typeArgCount > 0 {
+                            te.typeArgName0 = String_Concat(te.typeArgName0, "_");
+                            te.typeArgName0 = String_Concat(te.typeArgName0, b0.refType.typeArgName0);
+                        }
+                    } else if b0.refType.kind == tekPointer && b0.refType.pointerPointee != null as *TypeExpr {
+                        te.typeArgName0 = String_Concat(b0.refType.pointerPointee.typeName, "p");
+                    }
+                }
+            }
+            if te.typeArgCount > 1 && String_StartsWith(te.typeArgName1, "$") {
+                let b1: *Expr = Env_Lookup(env, te.typeArgName1);
+                if b1 != null as *Expr && b1.kind == ekMacroType && b1.refType != null as *TypeExpr {
+                    if b1.refType.kind == tekNamed {
+                        te.typeArgName1 = b1.refType.typeName;
+                    }
+                }
+            }
+        }
         if te.pointerPointee != null as *TypeExpr {
             te.pointerPointee = Macro_SubstType(te.pointerPointee, env);
             if te.kind == tekPointer && te.pointerPointee != null as *TypeExpr {
@@ -533,6 +576,27 @@ module MacroExpand {
         return te;
     }
 
+    // Substitute `$t` in Expr generic type-arg slots (Array_New<$t>)
+    func Macro_SubstGenericTypeArgs(e: *Expr, env: *MacroEnv) {
+        if e == null as *Expr { return; }
+        if e.genericTypeArgCount > 0 && String_StartsWith(e.genericTypeArg0, "$") {
+            let b0: *Expr = Env_Lookup(env, e.genericTypeArg0);
+            if b0 != null as *Expr && b0.kind == ekMacroType && b0.refType != null as *TypeExpr {
+                if b0.refType.kind == tekNamed {
+                    e.genericTypeArg0 = b0.refType.typeName;
+                }
+            }
+        }
+        if e.genericTypeArgCount > 1 && String_StartsWith(e.genericTypeArg1, "$") {
+            let b1: *Expr = Env_Lookup(env, e.genericTypeArg1);
+            if b1 != null as *Expr && b1.kind == ekMacroType && b1.refType != null as *TypeExpr {
+                if b1.refType.kind == tekNamed {
+                    e.genericTypeArg1 = b1.refType.typeName;
+                }
+            }
+        }
+    }
+
     // Fragment kind check: "ident" | "literal" | "block" | "stmt" | "pat" | "expr" | "tt"
     func Macro_FragMatches(kindStr: String, aexp: *Expr) -> bool {
         return Macro_CoerceArg(kindStr, aexp) != null as *Expr;
@@ -961,6 +1025,8 @@ module MacroExpand {
         c.child1 = Subst_Expr(c.child1, env, file, line, col);
         c.child2 = Subst_Expr(c.child2, env, file, line, col);
         c.child3 = Subst_Expr(c.child3, env, file, line, col);
+        // Array_New<$t> / Foo<$t,$u>
+        Macro_SubstGenericTypeArgs(c, env);
         // sizeof / cast / is type annotations
         if c.refType != null as *TypeExpr {
             c.refType = Macro_SubstType(c.refType, env);

tools/lsp_server.nim

@@ -21,9 +21,11 @@
 #          docs even when `extend T for I` has no methods (no open required).
 # v0.17.0: in-process diagnostics (lex/parse/sema) on open/change/save so the
 #          editor underlines errors in the live buffer without needing buxc.
+# v0.18.0: textDocument/formatting + rangeFormatting via bootstrap `formatSource`
+#          (same rules as `bux fmt` — 4-space brace indent).
 
 import std/[json, os, strutils, streams, tables, osproc, sequtils, sets]
-import lexer, parser, ast, sema, types, scope, source_location
+import lexer, parser, ast, sema, types, scope, source_location, fmt
 
 # ---------------------------------------------------------------------------
 # JSON-RPC Transport
@@ -2514,6 +2516,64 @@ proc handleDocumentSymbol(stream: FileStream, id: JsonNode, paramsNode: JsonNode
     })
   sendResponse(stream, id, arr)
 
+# ---------------------------------------------------------------------------
+# Document formatting (v0.18 — same engine as `bux fmt`)
+# ---------------------------------------------------------------------------
+
+proc lineCountAndLastLen(s: string): tuple[lines: int, lastLen: int] =
+  ## 0-based end position after last character (for full-document TextEdit).
+  if s.len == 0:
+    return (0, 0)
+  var lines = 0
+  var lastLen = 0
+  var i = 0
+  while i < s.len:
+    if s[i] == '\n':
+      inc lines
+      lastLen = 0
+    else:
+      inc lastLen
+    inc i
+  # Trailing content without final newline still occupies a line
+  if s[^1] != '\n':
+    # last line is incomplete — end character is lastLen
+    discard
+  else:
+    # ends with newline: end is (lines, 0) in LSP (exclusive end after last line)
+    discard
+  result = (lines, lastLen)
+
+proc fullDocumentEdit(uri: string, content: string, formatted: string): JsonNode =
+  ## Single TextEdit replacing the whole buffer with formatted text.
+  if formatted == content:
+    return newJArray()
+  let (endLine, endChar) = lineCountAndLastLen(content)
+  var arr = newJArray()
+  arr.add(%*{
+    "range": {
+      "start": {"line": 0, "character": 0},
+      "end": {"line": endLine, "character": endChar}
+    },
+    "newText": formatted
+  })
+  discard uri
+  return arr
+
+proc handleDocumentFormatting(stream: FileStream, id: JsonNode, paramsNode: JsonNode) =
+  ## textDocument/formatting — re-indent with 4 spaces (idempotent).
+  let uri = paramsNode["textDocument"]["uri"].getStr()
+  let doc = getDoc(uri)
+  let formatted = formatSource(doc.content)
+  sendResponse(stream, id, fullDocumentEdit(uri, doc.content, formatted))
+
+proc handleDocumentRangeFormatting(stream: FileStream, id: JsonNode, paramsNode: JsonNode) =
+  ## textDocument/rangeFormatting — whole-file format (indent is brace-global).
+  ## Editors that send a selection still get a consistent full reformat.
+  let uri = paramsNode["textDocument"]["uri"].getStr()
+  let doc = getDoc(uri)
+  let formatted = formatSource(doc.content)
+  sendResponse(stream, id, fullDocumentEdit(uri, doc.content, formatted))
+
 proc handleWorkspaceSymbol(stream: FileStream, id: JsonNode, paramsNode: JsonNode) =
   ## workspace/symbol — fuzzy-ish substring filter over workspace + open docs.
   let query = if paramsNode.hasKey("query"): paramsNode["query"].getStr().toLowerAscii() else: ""
@@ -3370,9 +3430,11 @@ proc handleMessage(stream: FileStream, msg: JsonNode) =
         "workspaceSymbolProvider": true,
         "callHierarchyProvider": true,
         "implementationProvider": true,
-        "typeHierarchyProvider": true
+        "typeHierarchyProvider": true,
+        "documentFormattingProvider": true,
+        "documentRangeFormattingProvider": true
       },
-      "serverInfo": {"name": "bux-lsp", "version": "0.17.0"}
+      "serverInfo": {"name": "bux-lsp", "version": "0.18.0"}
     })
     if paramsNode.hasKey("rootPath") and paramsNode["rootPath"].kind != JNull:
       rootPath = paramsNode["rootPath"].getStr()
@@ -3470,6 +3532,12 @@ proc handleMessage(stream: FileStream, msg: JsonNode) =
   of "typeHierarchy/subtypes":
     handleTypeHierarchySubtypes(stream, id, paramsNode)
 
+  of "textDocument/formatting":
+    handleDocumentFormatting(stream, id, paramsNode)
+
+  of "textDocument/rangeFormatting":
+    handleDocumentRangeFormatting(stream, id, paramsNode)
+
   else:
     if id != nil:
       sendError(stream, id, -32601, "method not found: " & methodName)

tools/smoke_freestanding.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# Smoke: freestanding runtime compiles under -ffreestanding; optional package build.
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+RT="$ROOT/rt/runtime_freestanding.c"
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+
+if [[ ! -f "$RT" ]]; then
+  echo "FAIL: missing $RT"
+  exit 1
+fi
+
+CC="${BUX_CC:-cc}"
+
+echo "=== freestanding: -ffreestanding -c runtime ==="
+"$CC" -ffreestanding -std=c11 -Wall -Wextra -c "$RT" -o "$TMP/rt_fs.o"
+echo "PASS: runtime_freestanding.o"
+
+echo "=== freestanding: BUX_RUNTIME=freestanding build hello-ish ==="
+mkdir -p "$TMP/pkg/src"
+cat > "$TMP/pkg/bux.toml" <<'EOF'
+[Package]
+Name = "fs_smoke"
+Version = "0.1.0"
+EOF
+cat > "$TMP/pkg/src/Main.bux" <<'EOF'
+func Main() -> int {
+    return 42;
+}
+EOF
+
+if [[ ! -x "$ROOT/buxc" ]]; then
+  echo "building buxc..."
+  (cd "$ROOT" && make build >/dev/null)
+fi
+
+# Hosted link still uses libc for crt0; runtime body is freestanding.
+BUX_RUNTIME=freestanding "$ROOT/buxc" build "$TMP/pkg" --release >/dev/null
+OUT="$TMP/pkg/build/fs_smoke"
+if [[ ! -x "$OUT" ]]; then
+  echo "FAIL: binary not produced"
+  exit 1
+fi
+CODE=$("$OUT"; echo $?)
+if [[ "$CODE" != "42" ]]; then
+  echo "FAIL: expected exit 42, got $CODE"
+  exit 1
+fi
+echo "PASS: freestanding runtime package exit 42"
+
+# Optional: object-level nostdlib link experiment (may need extra crt — soft)
+echo "=== freestanding: optional -ffreestanding object of Main.c ==="
+# Generate C then compile Main only with freestanding flags
+BUX_RUNTIME=freestanding "$ROOT/buxc" build "$TMP/pkg" --release >/dev/null
+if [[ -f "$TMP/pkg/build/main.c" ]]; then
+  if "$CC" -ffreestanding -std=c11 -c "$TMP/pkg/build/main.c" -o "$TMP/main_fs.o" 2>"$TMP/main_fs.err"; then
+    echo "PASS: main.c compiles under -ffreestanding"
+  else
+    # Hosted headers in generated C may pull stdint — not a hard fail
+    echo "SKIP: main.c -ffreestanding (generated C may need hosted headers)"
+    head -5 "$TMP/main_fs.err" || true
+  fi
+fi
+
+echo "PASS: freestanding smoke"

tools/smoke_lsp_formatting.sh

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+# Smoke: textDocument/formatting re-indents with 4 spaces (same as bux fmt).
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+LSP="$ROOT/tools/bux-lsp"
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+
+if [[ ! -x "$LSP" ]]; then
+  echo "building bux-lsp..."
+  (cd "$ROOT" && make lsp >/dev/null)
+fi
+
+# Intentionally bad indent (2 spaces)
+cat > "$TMP/Main.bux" <<'EOF'
+func Main() -> int {
+  let x: int = 1;
+    if x > 0 {
+  return 0;
+    }
+  return 1;
+}
+EOF
+
+rpc() {
+  local body="$1"
+  local len
+  len=$(printf '%s' "$body" | wc -c)
+  printf 'Content-Length: %s\r\n\r\n%s' "$len" "$body"
+}
+
+CONTENT_JSON=$(python3 -c 'import json,sys; print(json.dumps(open(sys.argv[1]).read()))' "$TMP/Main.bux")
+URI="file://$TMP/Main.bux"
+
+{
+  rpc '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{},"rootUri":"file://'"$TMP"'"}}'
+  rpc '{"jsonrpc":"2.0","method":"initialized","params":{}}'
+  rpc '{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"'"$URI"'","languageId":"bux","version":1,"text":'"$CONTENT_JSON"'}}}'
+  rpc '{"jsonrpc":"2.0","id":2,"method":"textDocument/formatting","params":{"textDocument":{"uri":"'"$URI"'"},"options":{"tabSize":4,"insertSpaces":true}}}'
+  rpc '{"jsonrpc":"2.0","id":3,"method":"shutdown","params":null}'
+  rpc '{"jsonrpc":"2.0","method":"exit","params":null}'
+} | "$LSP" 2>/dev/null | tr '\r' '\n' > "$TMP/out.txt"
+
+python3 - <<'PY' "$TMP/out.txt"
+import json, sys, re
+raw = open(sys.argv[1]).read()
+
+# Find response id=2 with result TextEdit array
+# Prefer structured parse of JSON objects containing "newText"
+ok = False
+version_ok = "0.18.0" in raw or '"documentFormattingProvider":true' in raw.replace(" ", "")
+if "0.18.0" not in raw and "documentFormattingProvider" not in raw:
+    # initialize result may be nested; still require a formatting response
+    pass
+
+# Extract TextEdit newText via regex / brace walk
+edits = []
+for m in re.finditer(r'"newText"\s*:\s*"((?:[^"\\]|\\.)*)"', raw):
+    edits.append(bytes(m.group(1), "utf-8").decode("unicode_escape"))
+
+if not edits:
+    print("FAIL: no TextEdit newText in formatting response")
+    print(raw[:3000])
+    sys.exit(1)
+
+formatted = edits[0]
+# Expected: 4-space indent after func {
+if "    let x: int = 1;" not in formatted:
+    print("FAIL: expected 4-space indent on let")
+    print(repr(formatted))
+    sys.exit(1)
+if "        if x > 0 {" not in formatted and "    if x > 0 {" not in formatted:
+    # after let at indent 1, if should be at indent 1 (same block) = 4 spaces
+    print("FAIL: unexpected if indent")
+    print(repr(formatted))
+    sys.exit(1)
+# Nested body of if at 8 spaces
+if "        return 0;" not in formatted:
+    print("FAIL: expected 8-space indent on return inside if")
+    print(repr(formatted))
+    sys.exit(1)
+
+print("PASS: LSP formatting smoke (4-space brace indent)")
+if "0.18.0" in raw:
+    print("PASS: serverInfo version 0.18.0")
+PY

vscode/README.md

@@ -8,8 +8,8 @@ Syntax highlighting, snippets, editor defaults, and **Language Server Protocol**
 |------|----------------|
 | **Syntax** | Keywords, types, `f"..."` interpolation, raw `` `...` `` strings, C-strings, macros (`macro!` / `name!()`), attributes (`@[Checked]`), numbers (hex/bin/oct + suffixes), lifetimes |
 | **Snippets** | `main`, `func`, `struct`, `enum`, `match`, `interface`, `extend`, `macro`, `checked`, … |
-| **LSP** | **Live error underlines** (red squiggles on edit), completion, hover, go-to-definition, references, rename, document/workspace symbols, call hierarchy, type hierarchy, go-to-implementation |
+| **LSP** | **Live error underlines** (red squiggles on edit), **Format Document** (same as `bux fmt`), completion, hover, go-to-definition, references, rename, document/workspace symbols, call hierarchy, type hierarchy, go-to-implementation |
-| **Editor** | Bracket colorization, smart indent / on-enter, fold regions (`// region`) |
+| **Editor** | Bracket colorization, smart indent / on-enter, fold regions (`// region`), **format-on-save** default for `[bux]` |
 | **Build** | `buxc` problem matcher for Tasks |
 
 ## Requirements

vscode/package.json

@@ -1,8 +1,8 @@
 {
     "name": "bux-lang",
     "displayName": "Bux Language Support",
-    "description": "Syntax highlighting, snippets, and full LSP support for Bux — live error underlines, hover, go-to-def, rename, call/type hierarchy",
+    "description": "Syntax highlighting, snippets, and full LSP support for Bux — live error underlines, Format Document, hover, go-to-def, rename, call/type hierarchy",
-    "version": "0.2.1",
+    "version": "0.2.2",
     "publisher": "bux-lang",
     "license": "MIT",
     "icon": "icon.png",
@@ -25,6 +25,7 @@
         "Programming Languages",
         "Snippets",
         "Linters",
+        "Formatters",
         "Other"
     ],
     "keywords": [
@@ -32,7 +33,8 @@
         "bux-lang",
         "programming-language",
         "lsp",
-        "syntax"
+        "syntax",
+        "formatter"
     ],
     "activationEvents": [
         "onLanguage:bux",
@@ -107,7 +109,7 @@
                 "bux.lsp.enabled": {
                     "type": "boolean",
                     "default": true,
-                    "description": "Enable the Bux language server (diagnostics, hover, go-to-definition, rename, hierarchy)."
+                    "description": "Enable the Bux language server (diagnostics, formatting, hover, go-to-definition, rename, hierarchy)."
                 },
                 "bux.lsp.path": {
                     "type": "string",
@@ -133,6 +135,7 @@
                 "editor.tabSize": 4,
                 "editor.insertSpaces": true,
                 "editor.detectIndentation": false,
+                "editor.formatOnSave": true,
                 "editor.quickSuggestions": {
                     "other": true,
                     "comments": false,