diff --git a/bootstrap/src/hmc/scan.ml b/bootstrap/src/hmc/scan.ml
index eee46ccb..157d3fe1 100644
--- a/bootstrap/src/hmc/scan.ml
+++ b/bootstrap/src/hmc/scan.ml
@@ -1618,6 +1618,143 @@ module Token = struct
     )
     |> Fmt.fmt ">"
 
+  let source = function
+    | Tok_and {source}
+    | Tok_also {source}
+    | Tok_as {source}
+    | Tok_conceal {source}
+    | Tok_effect {source}
+    | Tok_else {source}
+    | Tok_expose {source}
+    | Tok_external {source}
+    | Tok_false {source}
+    | Tok_fn {source}
+    | Tok_function {source}
+    | Tok_if {source}
+    | Tok_import {source}
+    | Tok_include {source}
+    | Tok_lazy {source}
+    | Tok_let {source}
+    | Tok_match {source}
+    | Tok_mutability {source}
+    | Tok_of {source}
+    | Tok_open {source}
+    | Tok_or {source}
+    | Tok_rec {source}
+    | Tok_then {source}
+    | Tok_true {source}
+    | Tok_type {source}
+    | Tok_when {source}
+    | Tok_with {source}
+    | Tok_tilde_op {source; _}
+    | Tok_qmark_op {source; _}
+    | Tok_star_star_op {source; _}
+    | Tok_star_op {source; _}
+    | Tok_slash_op {source; _}
+    | Tok_pct_op {source; _}
+    | Tok_plus_op {source; _}
+    | Tok_minus_op {source; _}
+    | Tok_at_op {source; _}
+    | Tok_caret_op {source; _}
+    | Tok_dollar_op {source; _}
+    | Tok_lt_op {source; _}
+    | Tok_eq_op {source; _}
+    | Tok_gt_op {source; _}
+    | Tok_bar_op {source; _}
+    | Tok_colon_op {source; _}
+    | Tok_dot_op {source; _}
+    | Tok_tilde {source}
+    | Tok_qmark {source}
+    | Tok_minus {source}
+    | Tok_lt {source}
+    | Tok_lt_eq {source}
+    | Tok_eq {source}
+    | Tok_lt_gt {source}
+    | Tok_gt_eq {source}
+    | Tok_gt {source}
+    | Tok_comma {source}
+    | Tok_dot {source}
+    | Tok_dot_dot {source}
+    | Tok_semi {source}
+    | Tok_colon {source}
+    | Tok_colon_colon {source}
+    | Tok_colon_eq {source}
+    | Tok_lparen {source}
+    | Tok_rparen {source}
+    | Tok_lbrack {source}
+    | Tok_rbrack {source}
+    | Tok_lcurly {source}
+    | Tok_rcurly {source}
+    | Tok_bar {source}
+    | Tok_lcapture {source}
+    | Tok_rcapture {source}
+    | Tok_larray {source}
+    | Tok_rarray {source}
+    | Tok_bslash {source}
+    | Tok_tick {source}
+    | Tok_caret {source}
+    | Tok_amp {source}
+    | Tok_xmark {source}
+    | Tok_arrow {source}
+    | Tok_carrow {source}
+    | Tok_source_directive {source; _}
+    | Tok_line_delim {source}
+    | Tok_indent {source; _}
+    | Tok_dedent {source; _}
+    | Tok_whitespace {source}
+    | Tok_hash_comment {source}
+    | Tok_paren_comment {source; _}
+    | Tok_uscore {source}
+    | Tok_uident {source; _}
+    | Tok_cident {source; _}
+    | Tok_codepoint {source; _}
+    | Tok_rstring {source; _}
+    | Tok_istring {source; _}
+    | Tok_fstring_lditto {source}
+    | Tok_fstring_interpolated {source; _}
+    | Tok_fstring_pct {source}
+    | Tok_fstring_pad {source; _}
+    | Tok_fstring_just {source; _}
+    | Tok_fstring_sign {source; _}
+    | Tok_fstring_alt {source}
+    | Tok_fstring_zpad {source}
+    | Tok_fstring_width_star {source}
+    | Tok_fstring_width {source; _}
+    | Tok_fstring_pmode {source; _}
+    | Tok_fstring_precision_star {source}
+    | Tok_fstring_precision {source; _}
+    | Tok_fstring_radix {source; _}
+    | Tok_fstring_notation {source; _}
+    | Tok_fstring_pretty {source}
+    | Tok_fstring_fmt {source; _}
+    | Tok_fstring_sep {source; _}
+    | Tok_fstring_label {source; _}
+    | Tok_fstring_lparen_caret {source}
+    | Tok_fstring_caret_rparen {source}
+    | Tok_fstring_rditto {source}
+    | Tok_r32 {source; _}
+    | Tok_r64 {source; _}
+    | Tok_u8 {source; _}
+    | Tok_i8 {source; _}
+    | Tok_u16 {source; _}
+    | Tok_i16 {source; _}
+    | Tok_u32 {source; _}
+    | Tok_i32 {source; _}
+    | Tok_u64 {source; _}
+    | Tok_i64 {source; _}
+    | Tok_u128 {source; _}
+    | Tok_i128 {source; _}
+    | Tok_u256 {source; _}
+    | Tok_i256 {source; _}
+    | Tok_u512 {source; _}
+    | Tok_i512 {source; _}
+    | Tok_nat {source; _}
+    | Tok_zint {source; _}
+    | Tok_end_of_input {source}
+    | Tok_misaligned {source}
+    | Tok_error {source; _}
+      -> source
+
   let malformations = function
     (* Keywords. *)
     | Tok_and _ | Tok_also _ | Tok_as _ | Tok_conceal _ | Tok_effect _ | Tok_else _ | Tok_expose _
@@ -1842,7 +1979,7 @@ let pp_line_state line_state formatter =
  * completing specifier scanning the state transition to `Fstring_body`, which is capable of
  * initiating the scan of a subsequent specifier. *)
 type fstring_state =
-  | Fstring_spec_pct_seen of ConcreteToken.t list
+  | Fstring_spec_pct_seen of Token.t list
   | Fstring_spec_pad_seen
   | Fstring_spec_just_seen
   | Fstring_spec_sign_seen
@@ -1863,14 +2000,14 @@ type fstring_state =
   | Fstring_spec_fmt_seen
   | Fstring_spec_sep_seen
   | Fstring_expr_value of Source.Cursor.t option (* Cursor is start of captured value expression. *)
-  | Fstring_value_seen of ConcreteToken.t
+  | Fstring_value_seen of Token.t
   | Fstring_body
-  | Fstring_rditto_seen of ConcreteToken.t
+  | Fstring_rditto_seen of Token.t
 
 let pp_fstring_state fstring_state formatter =
   match fstring_state with
   | Fstring_spec_pct_seen ctoks ->
-    formatter |> Fmt.fmt "Fstring_spec_pct " |> (List.pp ConcreteToken.pp) ctoks
+    formatter |> Fmt.fmt "Fstring_spec_pct " |> (List.pp Token.pp) ctoks
   | Fstring_spec_pad_seen -> formatter |> Fmt.fmt "Fstring_spec_pad_seen"
   | Fstring_spec_just_seen -> formatter |> Fmt.fmt "Fstring_spec_just_seen"
   | Fstring_spec_sign_seen -> formatter |> Fmt.fmt "Fstring_spec_sign_seen"
@@ -1892,9 +2029,9 @@ let pp_fstring_state fstring_state formatter =
   | Fstring_spec_sep_seen -> formatter |> Fmt.fmt "Fstring_spec_sep_seen"
   | Fstring_expr_value cursor_opt ->
     formatter |> Fmt.fmt "Fstring_exp_value " |> (Option.pp Source.Cursor.pp) cursor_opt
-  | Fstring_value_seen ctok -> formatter |> Fmt.fmt "Fstring_spec_pct " |> ConcreteToken.pp ctok
+  | Fstring_value_seen ctok -> formatter |> Fmt.fmt "Fstring_spec_pct " |> Token.pp ctok
   | Fstring_body -> formatter |> Fmt.fmt "Fstring_body"
-  | Fstring_rditto_seen ctok -> formatter |> Fmt.fmt "Fstring_spec_pct " |> ConcreteToken.pp ctok
+  | Fstring_rditto_seen ctok -> formatter |> Fmt.fmt "Fstring_spec_pct " |> Token.pp ctok
 
 type t = {
   tok_base: Source.Cursor.t;
@@ -1947,10 +2084,10 @@ let in_fstring t =
  * Convenience routines for reporting malformations. *)
 
 let malformation ~base ~past description =
-  AbstractToken.Rendition.Malformation.init ~base ~past ~description
+  Token.Rendition.Malformation.init ~base ~past ~description
 
 let malformed malformation =
-  AbstractToken.Rendition.of_mals [malformation]
+  Token.Rendition.of_mals [malformation]
 
 let unexpected_codepoint_source_directive base past =
   malformation ~base ~past "Unexpected codepoint in source directive"
@@ -2023,7 +2160,7 @@ module State = struct
         m: Realer.t;
         point_shift: sint;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2034,7 +2171,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m =
       R {m; point_shift=Sint.zero}
@@ -2083,7 +2220,7 @@ module State = struct
         m: real;
         ds: real; (* (ds * digit) scales digit to its fractional value. *)
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2094,7 +2231,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m =
       R {m; ds=1. /. 10.}
@@ -2120,7 +2257,7 @@ module State = struct
       | R of {
         m: Realer.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2130,7 +2267,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m =
       R {m}
@@ -2148,7 +2285,7 @@ module State = struct
       | R of {
         m: real;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2158,7 +2295,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m =
       R {m}
@@ -2177,7 +2314,7 @@ module State = struct
         m: Realer.t;
         exp_sign: Sign.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2188,7 +2325,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m ~exp_sign =
       R {m; exp_sign}
@@ -2207,7 +2344,7 @@ module State = struct
         m: real;
         exp_sign: Sign.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2218,7 +2355,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m ~exp_sign =
       R {m; exp_sign}
@@ -2238,7 +2375,7 @@ module State = struct
         exp_sign: Sign.t;
         exp: Nat.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2250,7 +2387,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m ~exp_sign ~exp =
       R {m; exp_sign; exp}
@@ -2286,7 +2423,7 @@ module State = struct
         exp_sign: Sign.t;
         exp: Nat.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2298,7 +2435,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~m ~exp_sign ~exp =
       R {m; exp_sign; exp}
@@ -2332,7 +2469,7 @@ module State = struct
       | R of {
         r: Realer.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2342,7 +2479,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~r =
       R {r}
@@ -2360,7 +2497,7 @@ module State = struct
       | R of {
         r: real;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2370,7 +2507,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~r =
       R {r}
@@ -2389,7 +2526,7 @@ module State = struct
         r: Realer.t;
         bitwidth: Nat.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2400,7 +2537,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~r ~bitwidth =
       R {r; bitwidth}
@@ -2423,7 +2560,7 @@ module State = struct
         r: real;
         bitwidth: Nat.t;
       }
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2434,7 +2571,7 @@ module State = struct
         |> Fmt.fmt "}"
       | Malformations mals ->
         formatter
-        |> Fmt.fmt "Malformations " |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+        |> Fmt.fmt "Malformations " |> (List.pp Token.Rendition.Malformation.pp) mals
 
     let init ~r ~bitwidth =
       R {r; bitwidth}
@@ -2562,13 +2699,13 @@ module State = struct
 
   module Src_directive_path = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
     }
 
     let pp {mals; path} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "}"
 
@@ -2585,14 +2722,14 @@ module State = struct
 
   module Src_directive_path_bslash = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       bslash_cursor: Source.Cursor.t;
     }
 
     let pp {mals; path; bslash_cursor} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; bslash_cursor=" |> Text.Pos.pp (Source.Cursor.pos bslash_cursor)
       |> Fmt.fmt "}"
@@ -2610,14 +2747,14 @@ module State = struct
 
   module Src_directive_path_bslash_u_lcurly = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       bslash_cursor: Source.Cursor.t;
     }
 
     let pp {mals; path; bslash_cursor} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; bslash_cursor=" |> Text.Pos.pp (Source.Cursor.pos bslash_cursor)
       |> Fmt.fmt "}"
@@ -2631,7 +2768,7 @@ module State = struct
 
   module Src_directive_path_bslash_u_lcurly_hex = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       bslash_cursor: Source.Cursor.t;
       hex: Nat.t;
@@ -2639,7 +2776,7 @@ module State = struct
 
     let pp {mals; path; bslash_cursor; hex} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; bslash_cursor=" |> Text.Pos.pp (Source.Cursor.pos bslash_cursor)
       |> Fmt.fmt "; hex=" |> Nat.fmt ~alt:true ~radix:Radix.Hex ~pretty:true hex
@@ -2666,7 +2803,7 @@ module State = struct
 
   module Src_directive_line = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line_cursor: Source.Cursor.t;
       line: Nat.t option;
@@ -2674,7 +2811,7 @@ module State = struct
 
     let pp {mals; path; line_cursor; line} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line_cursor=" |> Text.Pos.pp (Source.Cursor.pos line_cursor)
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
@@ -2689,14 +2826,14 @@ module State = struct
 
   module Src_directive_line_colon = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line: Nat.t option;
     }
 
     let pp {mals; path; line} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
       |> Fmt.fmt "}"
@@ -2710,7 +2847,7 @@ module State = struct
 
   module Src_directive_indent = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line: Nat.t option;
       indent_cursor: Source.Cursor.t;
@@ -2719,7 +2856,7 @@ module State = struct
 
     let pp {mals; path; line; indent_cursor; indent} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
       |> Fmt.fmt "; indent_cursor=" |> Text.Pos.pp (Source.Cursor.pos indent_cursor)
@@ -2738,14 +2875,14 @@ module State = struct
 
   module Src_directive_indent_0 = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line: Nat.t option;
     }
 
     let pp {mals; path; line} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
       |> Fmt.fmt "}"
@@ -2759,7 +2896,7 @@ module State = struct
 
   module Src_directive_indent_plus = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line: Nat.t option;
       indent: Nat.t option;
@@ -2767,7 +2904,7 @@ module State = struct
 
     let pp {mals; path; line; indent} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
       |> Fmt.fmt "; indent=" |> (Option.pp Nat.pp) indent
@@ -2782,7 +2919,7 @@ module State = struct
 
   module Src_directive_omit = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       path: codepoint list option;
       line: Nat.t option;
       indent: Nat.t option;
@@ -2792,7 +2929,7 @@ module State = struct
 
     let pp {mals; path; line; indent; omit_cursor; omit} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; path=" |> (Option.pp (List.pp Codepoint.pp)) path
       |> Fmt.fmt "; line=" |> (Option.pp Nat.pp) line
       |> Fmt.fmt "; indent=" |> (Option.pp Nat.pp) indent
@@ -2864,12 +3001,12 @@ module State = struct
 
   module Codepoint_mal = struct
     type t = {
-      mal: AbstractToken.Rendition.Malformation.t;
+      mal: Token.Rendition.Malformation.t;
     }
 
     let pp {mal} formatter =
       formatter
-      |> Fmt.fmt "{mal=" |> AbstractToken.Rendition.Malformation.pp mal |> Fmt.fmt "}"
+      |> Fmt.fmt "{mal=" |> Token.Rendition.Malformation.pp mal |> Fmt.fmt "}"
 
     let init ~mal =
       {mal}
@@ -2877,13 +3014,13 @@ module State = struct
 
   module Rstring_ltag = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       ltag_base: Source.Cursor.t;
     }
 
     let pp {mals; ltag_base} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; ltag_base=" |> Source.Cursor.pp ltag_base
       |> Fmt.fmt "}"
 
@@ -2896,14 +3033,14 @@ module State = struct
 
   module Rstring_body = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       ltag: Source.Slice.t;
       body_base: Source.Cursor.t;
     }
 
     let pp {mals; ltag; body_base} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; ltag=" |> Source.Slice.pp ltag
       |> Fmt.fmt "; body_base=" |> Source.Cursor.pp body_base
       |> Fmt.fmt "}"
@@ -2917,7 +3054,7 @@ module State = struct
 
   module Rstring_rtag = struct
     type t = {
-      mals: AbstractToken.Rendition.Malformation.t list;
+      mals: Token.Rendition.Malformation.t list;
       ltag: Source.Slice.t;
       body: Source.Slice.t;
       ltag_cursor: Source.Cursor.t;
@@ -2925,7 +3062,7 @@ module State = struct
 
     let pp {mals; ltag; ltag_cursor; body} formatter =
       formatter
-      |> Fmt.fmt "{mals=" |> (List.pp AbstractToken.Rendition.Malformation.pp) mals
+      |> Fmt.fmt "{mals=" |> (List.pp Token.Rendition.Malformation.pp) mals
       |> Fmt.fmt "; ltag=" |> Source.Slice.pp ltag
       |> Fmt.fmt "; body=" |> Source.Slice.pp body
       |> Fmt.fmt "; ltag_cursor=" |> Source.Cursor.pp ltag_cursor
@@ -2944,7 +3081,7 @@ module State = struct
   module CodepointAccum = struct
     type t =
       | Codepoints of codepoint list
-      | Malformations of AbstractToken.Rendition.Malformation.t list
+      | Malformations of Token.Rendition.Malformation.t list
 
     let pp t formatter =
       match t with
@@ -2952,7 +3089,7 @@ module State = struct
         formatter |> Fmt.fmt "(Codepoints " |> (List.pp Codepoint.pp) cps |> Fmt.fmt ")"
       | Malformations mals ->
         formatter |> Fmt.fmt "(Malformations "
-        |> (List.pp AbstractToken.Rendition.Malformation.pp) mals |> Fmt.fmt ")"
+        |> (List.pp Token.Rendition.Malformation.pp) mals |> Fmt.fmt ")"
 
     let empty = Codepoints []
 
@@ -2964,6 +3101,7 @@ module State = struct
       | Codepoints _ -> Malformations [mal]
       | Malformations mals -> Malformations (mal :: mals)
 
+(* XXX
     let to_atok_istring = function
       | Codepoints cps -> AbstractToken.Tok_istring (Constant (String.of_list_rev cps))
       | Malformations mals -> AbstractToken.Tok_istring (AbstractToken.Rendition.of_mals mals)
@@ -2972,6 +3110,14 @@ module State = struct
       | Codepoints cps -> AbstractToken.Tok_fstring_interpolated (Constant (String.of_list_rev cps))
       | Malformations mals ->
         AbstractToken.Tok_fstring_interpolated (AbstractToken.Rendition.of_mals mals)
+*)
+    let to_istring = function
+      | Codepoints cps -> Token.Rendition.Constant (String.of_list_rev cps)
+      | Malformations mals -> Token.Rendition.of_mals mals
+
+    let to_fstring_interpolated = function
+      | Codepoints cps -> Token.Rendition.Constant (String.of_list_rev cps)
+      | Malformations mals -> Token.Rendition.of_mals mals
   end
 
   module Istring_body = struct
@@ -3448,7 +3594,7 @@ module Dfa = struct
   type transition =
     | Advance of View.t * State.t
     | Retry of State.t
-    | Accept of ConcreteToken.t
+    | Accept of Token.t
 
   type action0 = View.t -> t -> t * transition
   and node0 = {
@@ -3514,6 +3660,7 @@ module Dfa = struct
     let t', transition = action1 state_payload view' t in
     t', transition
 
+(* XXX Remove.
   let accept_ctok ctok cursor t =
     {t with tok_base=cursor}, Accept ctok
 
@@ -3528,8 +3675,24 @@ module Dfa = struct
 
   let accept_pexcl atok View.{ppcursor; _} t =
     accept atok ppcursor t
+*)
+
+  let accept_tok tok cursor t =
+    {t with tok_base=cursor}, Accept tok
+
+  let source_at cursor t =
+    Source.Slice.of_cursors ~base:t.tok_base ~past:cursor
+
+  let source_incl View.{cursor; _} t =
+    source_at cursor t
+
+  let source_excl View.{pcursor; _} t =
+    source_at pcursor t
 
-  let accept_source_directive atok View.{cursor; _} t =
+  let source_pexcl {View.ppcursor; _} t =
+    source_at ppcursor t
+
+  let accept_source_directive source_directive View.{cursor; _} t =
     (* Treat the directive as having come from the unbiased source. Rebias the cursors such that
      * they are unbiased. This is different than unbiasing, in that it preserves the cursors' bias
      * chain, which enables recovering source bias when moving leftwards. *)
@@ -3542,13 +3705,13 @@ module Dfa = struct
       end in
       f base cursor
     end in
-    let cursor', level' = match atok with
-      | AbstractToken.Tok_source_directive Constant {path=None; line=None; io=None}
+    let cursor', level' = match source_directive with
+      | Token.Rendition.Constant Token.{path=None; line=None; io=None}
         -> begin
             (* Rebias the source such that it is unbiased. *)
             past, Level.reset t.level
           end
-      | AbstractToken.Tok_source_directive Constant {path; line; io} -> begin
+      | Constant {path; line; io} -> begin
           let source = Source.Cursor.container past in
           let path = match path with
             | None -> Source.path source
@@ -3570,17 +3733,19 @@ module Dfa = struct
           let source' = Source.bias ~path ~line_bias ~col_bias source in
           (Source.Cursor.bias source' past), Level.embed (indent / 4L) t.level
         end
-      | AbstractToken.Tok_source_directive Malformed _ -> past, t.level
-      | _ -> not_reached ()
+      | Malformed _ -> past, t.level
     in
-    {t with tok_base=cursor'; level=level'}, Accept (ConcreteToken.ctok_at ~base ~past atok)
+    let source = Source.Slice.of_cursors ~base ~past in
+    let tok = Token.Tok_source_directive {source; source_directive} in
+    {t with tok_base=cursor'; level=level'}, Accept tok
 
-  let accept_line_break atok cursor t =
+  let accept_whitespace_incl View.{cursor; _} t =
     {t with tok_base=cursor; line_state=Line_begin},
-    Accept (ConcreteToken.ctok_at ~base:t.tok_base ~past:cursor atok)
+    Accept (Token.Tok_whitespace {source=source_at cursor t})
 
-  let accept_line_break_incl atok View.{cursor; _} t =
-    accept_line_break atok cursor t
+  let accept_hash_comment_incl View.{cursor; _} t =
+    {t with tok_base=cursor; line_state=Line_begin},
+    Accept (Token.Tok_hash_comment {source=source_at cursor t})
 
   let fstring_push fstring_state t =
     {t with fstring_states=fstring_state :: t.fstring_states}
@@ -3591,27 +3756,59 @@ module Dfa = struct
   let fstring_trans fstring_state t =
     fstring_push fstring_state (fstring_pop t)
 
+(*
   let accept_fstring_push_ctok fstring_state ctok cursor t =
     accept_ctok ctok cursor (fstring_push fstring_state t)
+*)
 
+  let accept_fstring_push_tok fstring_state ctok cursor t =
+    accept_tok ctok cursor (fstring_push fstring_state t)
+
+(*
   let accept_fstring_push_ctok_incl fstring_state ctok View.{cursor; _} t =
     accept_fstring_push_ctok fstring_state ctok cursor t
+*)
+
+  let accept_fstring_push_tok_incl fstring_state tok View.{cursor; _} t =
+    accept_fstring_push_tok fstring_state tok cursor t
 
+(*
   let accept_fstring_pop_ctok ctok cursor t =
     accept_ctok ctok cursor (fstring_pop t)
+*)
+
+  let accept_fstring_pop_tok tok cursor t =
+    accept_tok tok cursor (fstring_pop t)
 
+(*
   let accept_fstring_pop atok cursor t =
     accept_fstring_pop_ctok (ConcreteToken.ctok_at ~base:t.tok_base ~past:cursor atok) cursor t
+*)
 
+(*
   let accept_fstring_trans_ctok fstring_state ctok cursor t =
     accept_ctok ctok cursor (fstring_trans fstring_state t)
+*)
 
+  let accept_fstring_trans_tok fstring_state tok cursor t =
+    accept_tok tok cursor (fstring_trans fstring_state t)
+
+(*
   let accept_fstring_trans_ctok_incl fstring_state ctok View.{cursor; _} t =
     accept_fstring_trans_ctok fstring_state ctok cursor t
+*)
+
+  let accept_fstring_trans_tok_incl fstring_state tok View.{cursor; _} t =
+    accept_fstring_trans_tok fstring_state tok cursor t
 
+(*
   let accept_fstring_trans fstring_state atok cursor t =
     accept_fstring_trans_ctok fstring_state (ConcreteToken.ctok_at ~base:t.tok_base ~past:cursor
         atok) cursor t
+*)
+
+  let accept_fstring_trans fstring_state tok cursor t =
+    accept_fstring_trans_tok fstring_state tok cursor t
 
   let accept_fstring_trans_incl trans atok View.{cursor; _} t =
     accept_fstring_trans trans atok cursor t
@@ -3637,18 +3834,27 @@ module Dfa = struct
   let node0_start =
     {
       edges0=map_of_cps_alist [
-        (",", accept_incl Tok_comma);
-        (";", accept_incl Tok_semi);
+        (",", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_comma {source=source_incl view t}) cursor t);
+        (";", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_semi {source=source_incl view t}) cursor t);
         ("(", advance State_lparen);
-        (")", accept_incl Tok_rparen);
+        (")", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_rparen {source=source_incl view t}) cursor t);
         ("[", advance State_lbrack);
-        ("]", accept_incl Tok_rbrack);
-        ("{", accept_incl Tok_lcurly);
-        ("}", accept_incl Tok_rcurly);
-        ("\\", accept_incl Tok_bslash);
-        ("&", accept_incl Tok_amp);
-        ("!", accept_incl Tok_xmark);
-        ("\n", accept_line_break_incl Tok_whitespace);
+        ("]", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_rbrack {source=source_incl view t}) cursor t);
+        ("{", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_lcurly {source=source_incl view t}) cursor t);
+        ("}", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_rcurly {source=source_incl view t}) cursor t);
+        ("\\", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_bslash {source=source_incl view t}) cursor t);
+        ("&", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_amp {source=source_incl view t}) cursor t);
+        ("!", fun (View.{cursor; _} as view) t ->
+          accept_tok (Tok_xmark {source=source_incl view t}) cursor t);
+        ("\n", accept_whitespace_incl);
         ("~", advance State_tilde);
         ("?", advance State_qmark);
         ("*", advance State_star);
@@ -3682,16 +3888,18 @@ module Dfa = struct
       ];
       default0=(fun (View.{cursor; _} as view) t ->
         let mal = malformation ~base:t.tok_base ~past:cursor "Unsupported codepoint" in
-        accept_incl (Tok_error [mal]) view t
+        accept_tok (Tok_error {source=source_incl view t; error=[mal]}) cursor t
       );
-      eoi0=(fun view t ->
-        let accept_dentation atok View.{cursor; _} t = begin
-          accept atok cursor {t with line_state=Line_body}
-        end in
+      eoi0=(fun (View.{cursor; _} as view) t ->
         match Level.level t.level, t.line_state with
-        | 0L, Line_begin -> accept_dentation Tok_line_delim view t
-        | 0L, _ -> accept_incl Tok_end_of_input view t
-        | _ -> accept_dentation (Tok_dedent (Constant ())) view {t with level=Level.pred t.level}
+        | 0L, Line_begin -> accept_tok (Tok_line_delim {source=source_incl view t}) cursor t
+        | 0L, _ ->  accept_tok (Tok_end_of_input {source=source_incl view t}) cursor t
+        | _ -> begin
+          accept_tok (Tok_dedent {
+            source=source_incl view t;
+            dedent=(Constant ())
+          }) cursor {t with level=Level.pred t.level}
+        end
       );
     }
 
@@ -4630,7 +4838,10 @@ module Dfa = struct
             advance (State_real_dec_dot (State.Real_dec_dot.mals ~mals:[mal])) view t
         );
       ];
+      default0=(fun view t -> Token.Tok_r64 {source=source_excl view t; r64=(Constant 0.)})
+(*XXX
       default0=accept_excl (AbstractToken.Tok_r64 (Constant 0.));
+*)
       eoi0=accept_incl (AbstractToken.Tok_r64 (Constant 0.));
     }
 
@@ -5197,9 +5408,9 @@ module Dfa = struct
             | Some _, None
             | None, Some _ -> not_reached ()
           in
-          AbstractToken.Tok_source_directive (Constant {path; line; io})
+          Token.Rendition.Constant Token.{path; line; io}
         end
-      | _ :: _ -> AbstractToken.Tok_source_directive (AbstractToken.Rendition.of_mals mals)
+      | _ :: _ -> Token.Rendition.of_mals mals
 
     let node0_colon = {
       edges0=map_of_cps_alist [
@@ -5798,7 +6009,7 @@ module Dfa = struct
             match t.line_state with
             | Line_begin -> accept_incl Tok_whitespace view t
             | Line_whitespace
-            | Line_start_col _ -> accept_line_break_incl Tok_whitespace view t
+            | Line_start_col _ -> accept_whitespace_incl view t
             | Line_body -> not_reached ()
         );
       ];
@@ -5835,7 +6046,7 @@ module Dfa = struct
     let node0_space = {
       edges0=map_of_cps_alist [
         (" ", advance State_dentation_space);
-        ("\n", accept_line_break_incl Tok_whitespace);
+        ("\n", accept_whitespace_incl);
       ];
       default0=accept_whitespace_excl;
       eoi0=accept_whitespace_incl;
@@ -5845,7 +6056,7 @@ module Dfa = struct
   let node0_whitespace = {
     edges0=map_of_cps_alist [
       (" ", advance State_whitespace);
-      ("\n", accept_line_break_incl Tok_whitespace);
+      ("\n", accept_whitespace_incl);
     ];
     default0=accept_excl Tok_whitespace;
     eoi0=accept_incl Tok_whitespace;
@@ -5853,10 +6064,10 @@ module Dfa = struct
 
   let node0_hash_comment = {
     edges0=map_of_cps_alist [
-      ("\n", accept_line_break_incl Tok_hash_comment);
+      ("\n", accept_hash_comment_incl);
     ];
     default0=advance State_hash_comment;
-    eoi0=accept_line_break_incl Tok_hash_comment;
+    eoi0=accept_hash_comment_incl;
   }
 
   module Codepoint_ = struct
@@ -6183,29 +6394,33 @@ module Dfa = struct
               match in_fstring t with
               | false -> begin
                   let interpolated_base = Source.Cursor.succ t.tok_base in
-                  let lditto_ctok = ConcreteToken.ctok_at ~base:t.tok_base ~past:interpolated_base
-                      Tok_fstring_lditto in
-                  let pct_ctok = ConcreteToken.ctok_at ~base:pcursor ~past:cursor Tok_fstring_pct in
+                  let lditto_tok =
+                    Token.Tok_fstring_lditto {source=source_at interpolated_base t} in
+                  let pct_tok = Token.Tok_fstring_pct {source=Source.Slice.of_cursors
+                    ~base:pcursor ~past:cursor} in
                   let fstring_state = match Source.Cursor.(interpolated_base = pcursor) with
-                    | true -> Fstring_spec_pct_seen [pct_ctok]
+                    | true -> Fstring_spec_pct_seen [pct_tok]
                     | false -> begin
-                        let interpolated_ctok = ConcreteToken.ctok_at ~base:interpolated_base
-                            ~past:pcursor (State.CodepointAccum.to_atok_fstring_interpolated accum)
-                        in
-                        Fstring_spec_pct_seen [interpolated_ctok; pct_ctok]
+                        let interpolated_tok = Token.Tok_fstring_interpolated {
+                          source=Source.Slice.of_cursors ~base:interpolated_base ~past:pcursor;
+                          fstring_interpolated=State.CodepointAccum.to_fstring_interpolated accum
+                        } in
+                        Fstring_spec_pct_seen [interpolated_tok; pct_tok]
                       end
                   in
-                  accept_fstring_push_ctok_incl fstring_state lditto_ctok view t
+                  accept_fstring_push_ctok_incl fstring_state lditto_tok view t
                 end
               | true -> begin
-                  let pct_ctok = ConcreteToken.ctok_at ~base:pcursor ~past:cursor Tok_fstring_pct in
+                  let pct_tok = Token.Tok_fstring_pct {source=Source.Slice.of_cursors ~base:pcursor
+                    ~past:cursor} in
                   let fstring_state, ctok = match Source.Cursor.(t.tok_base = pcursor) with
-                    | true -> Fstring_spec_pct_seen [], pct_ctok
+                    | true -> Fstring_spec_pct_seen [], pct_tok
                     | false -> begin
-                        let interpolated_ctok = ConcreteToken.ctok_at ~base:t.tok_base
-                            ~past:pcursor (State.CodepointAccum.to_atok_fstring_interpolated accum)
-                        in
-                        Fstring_spec_pct_seen [pct_ctok], interpolated_ctok
+                        let interpolated_tok = Token.Tok_fstring_interpolated {
+                          source=source_excl view t;
+                          fstring_interpolated=State.CodepointAccum.to_fstring_interpolated accum
+                        } in
+                        Fstring_spec_pct_seen [pct_tok], interpolated_tok
                       end
                   in
                   accept_fstring_trans_ctok_incl fstring_state ctok view t
@@ -6214,17 +6429,19 @@ module Dfa = struct
           ("\"", fun {accum} (View.{pcursor; cursor; _} as view) t ->
               match in_fstring t with
               | true -> begin
-                  let rditto_ctok = ConcreteToken.ctok_at ~base:pcursor ~past:cursor
-                      Tok_fstring_rditto in
+                  let rditto_tok = Token.Tok_fstring_rditto {source=Source.Slice.of_cursors
+                    ~base:pcursor ~past:cursor} in
                   let fstring_states' = List.tl t.fstring_states in
                   match Source.Cursor.(t.tok_base = pcursor) with
                   | true ->
-                    {t with tok_base=cursor; fstring_states=fstring_states'}, Accept rditto_ctok
+                    {t with tok_base=cursor; fstring_states=fstring_states'}, Accept rditto_tok
                   | false -> begin
-                      let interpolated_ctok = ConcreteToken.ctok_at ~base:t.tok_base
-                          ~past:pcursor (State.CodepointAccum.to_atok_fstring_interpolated accum) in
-                      accept_fstring_trans_ctok_incl (Fstring_rditto_seen rditto_ctok)
-                        interpolated_ctok view t
+                      let interpolated_tok = Token.Tok_fstring_interpolated {
+                        source=source_excl view t;
+                        fstring_interpolated=State.CodepointAccum.to_fstring_interpolated accum
+                      } in
+                      accept_fstring_trans_ctok_incl (Fstring_rditto_seen rditto_tok)
+                        interpolated_tok view t
                     end
                 end
               | false -> accept_istring_incl accum view t
diff --git a/bootstrap/src/hmc/scan.mli b/bootstrap/src/hmc/scan.mli
index a1b99d63..ff26cbed 100644
--- a/bootstrap/src/hmc/scan.mli
+++ b/bootstrap/src/hmc/scan.mli
@@ -461,6 +461,8 @@ module Token : sig
 
   val pp: t -> (module Fmt.Formatter) -> (module Fmt.Formatter)
 
+  val source: t -> Source.Slice.t
+
   val malformations: t -> Rendition.Malformation.t list
   (** [malformations t] returns a list of malformations associated with [t], or an empty list if
       there are no malformations. This function can be used on any token variant, even if no
@@ -481,7 +483,7 @@ val cursor: t -> Source.Cursor.t
 (** [cursor t] returns the cursor at the scanner's current position. This cursor is equivalent to
     the base of the token returned by [next t]. *)
 
-val next: t -> t * ConcreteToken.t
+val next: t -> t * Token.t
 (** [next t] scans the next token past the tokens scanned by [t]'s predecessor state(s) and returns
     the scanner's successor state along with a token. If [t] is at the end of input, there is no
     successor state, and [t, EndOfInput] is returned. *)