Insert grammar: Form C type-awareness via lookahead (ADR-0024 §Phase D)

Form C (`insert into T (vals)`) shared the `(` opener with Form A,
so its paren was an untyped Repeated(Choice(literal, ident)) — values
weren't type- or count-checked at parse time (handoff-12 §2.2).

New Node::Lookahead variant: a factory that peeks the source. The
insert first-paren factory inspects the first token — a value literal
routes the contents through the typed column_value_list (Form B
dispatch contract: per-non-auto-column typed slots); an identifier or
empty paren routes to a Form A column-name list. So Form C now gets
the same per-column typed slots, hints, and parse-time type/count
checking Form B has.

The explicit-Choice-branch split is impossible here (committed-choice
semantics commit after `(` matches); lookahead is the only route, and
DynamicSubgrammar factories couldn't see the source. Node::Lookahead
is not memoized — its output depends on source — but it returns only
a small node (a Repeated, or a thin DynamicSubgrammar wrapper that
delegates to the memoized column_value_list).

`insert into T (` now cleanly shows Form A column candidates instead
of mixed Form-A/C suggestions. Form C matrix tests updated for the
type-aware behaviour.

src/dsl/grammar/data.rs

@@ -18,9 +18,10 @@
 
 use crate::dsl::command::{Command, RowFilter};
 use crate::dsl::grammar::{
-    CommandNode, HintMode, IdentSource, Node, ValidationError, Word,
+    CommandNode, IdentSource, Node, ValidationError, Word,
     shared::{column_value_list, current_column_value},
 };
+use crate::dsl::walker::context::WalkContext;
 use crate::dsl::value::Value;
 use crate::dsl::walker::outcome::{MatchedItem, MatchedKind, MatchedPath};
 
@@ -52,25 +53,6 @@ const TABLE_NAME_INSERT: Node = Node::Ident {
         writes_user_listed_column: false,
 };
 
-// `value_literal` — null / true / false / number / string. The
-// chumsky-side equivalent (`value_literal()` in dsl/parser.rs).
-const VALUE_LITERAL_CHOICES: &[Node] = &[
-    Node::Word(Word::keyword("null")),
-    Node::Word(Word::keyword("true")),
-    Node::Word(Word::keyword("false")),
-    Node::NumberLit { validator: None },
-    Node::StringLit,
-];
-const VALUE_LITERAL_INNER: Node = Node::Choice(VALUE_LITERAL_CHOICES);
-/// Value-literal slot with the `ProseOnly` HintMode
-/// (ADR-0024 §HintMode-per-node) — the hint resolver surfaces
-/// the generic "Type a value: …" prose rather than the
-/// misleading `null`/`true`/`false` candidate trio.
-const VALUE_LITERAL: Node = Node::Hinted {
-    mode: HintMode::ProseOnly("hint.value_literal_slot"),
-    inner: &VALUE_LITERAL_INNER,
-};
-
 // =================================================================
 // show — `show (data|table) <T>`
 // =================================================================
@@ -97,43 +79,85 @@ const SHOW_SHAPE: Node = Node::Choice(SHOW_CHOICES);
 // =================================================================
 //
 // Forms A (with column list) and C (bare value list) both start
-// with `(`. To avoid the walker's "first commit wins" semantics
+// with `(`. The walker's "first commit wins" Choice semantics
-// rejecting Form C when the inner content is values rather than
+// can't pick between them after the `(` matches, so the first
-// column names, the inside of the first paren is parsed as a
+// paren's contents are resolved by a `Node::Lookahead` factory
-// repeated `Choice(Ident, ValueLiteral)`. The AST builder then
+// (`insert_first_paren`): it peeks the first token to decide.
-// disambiguates: if a `values` keyword follows the first paren,
+//
-// the inner content was column names; otherwise it was values.
+// - First token is a value literal (number / string /
+//   null / true / false) → Form C → the typed `column_value_list`
+//   (same dispatch contract as Form B — ADR-0024 §Phase D Form-C
+//   type-awareness). Form C values are now type-checked at parse
+//   time, not only at bind time.
+// - Otherwise (column-name identifier, or an empty paren) →
+//   Form A → a repeated column-name list. The idents write
+//   `WalkContext::user_listed_columns` so the trailing
+//   `values (…)` slots mirror the user's selection.
 
-const INSERT_PAREN_ITEM_CHOICES: &[Node] = &[
+/// Form A's column-name slot. `static` (not `const`) so the
-    // VALUE_LITERAL first so that `true`/`false`/`null` match
+/// `insert_first_paren` factory can take a `&'static` reference
-    // their Word branch rather than the broader Ident{Columns}
+/// to it when building the repeated list at walk time.
-    // catch-all (consume_ident doesn't filter against the
+static FORM_A_COLUMN: Node = Node::Ident {
-    // keyword set; without this ordering, `(true)` would lex
-    // as a column-name list).
-    VALUE_LITERAL,
-    Node::Ident {
     source: IdentSource::Columns,
     role: "insert_first_item",
     validator: None,
     highlight_override: None,
     writes_table: false,
     writes_column: false,
-        // Form A signal: when the user lists explicit columns
-        // in `insert into <T> (col1, col2, …)`, the walker
-        // appends each matched name to
-        // `WalkContext::user_listed_columns`. The inner
-        // `values (…)` slot list then mirrors that user
-        // selection instead of the auto-filtered default
-        // (ADR-0024 §Phase D §column_value_list).
     writes_user_listed_column: true,
-    },
-];
-const INSERT_PAREN_ITEM: Node = Node::Choice(INSERT_PAREN_ITEM_CHOICES);
-const INSERT_PAREN_LIST: Node = Node::Repeated {
-    inner: &INSERT_PAREN_ITEM,
-    separator: Some(&Node::Punct(',')),
-    min: 1,
 };
+static INSERT_COMMA: Node = Node::Punct(',');
+
+/// First-paren resolver (ADR-0024 §Phase D Form-C type-awareness).
+/// Peeks the first token after `(` to route to Form A's
+/// column-name list or Form C's typed value list.
+fn insert_first_paren(_ctx: &WalkContext, source: &str, pos: usize) -> Node {
+    if first_paren_item_is_value_literal(source, pos) {
+        // Form C — bare value list. `column_value_list` with no
+        // user-listed columns dispatches per non-auto-generated
+        // column, exactly as Form B does.
+        Node::DynamicSubgrammar(column_value_list)
+    } else {
+        // Form A (or Form A in progress / empty paren).
+        Node::Repeated {
+            inner: &FORM_A_COLUMN,
+            separator: Some(&INSERT_COMMA),
+            min: 1,
+        }
+    }
+}
+
+/// True when the first token after the insert `(` is a
+/// value literal — the signal that the paren is a Form C value
+/// list rather than a Form A column-name list. An empty paren
+/// or an identifier-shaped token (a column name) returns false.
+fn first_paren_item_is_value_literal(source: &str, pos: usize) -> bool {
+    use crate::dsl::walker::lex_helpers::{
+        consume_ident, consume_number_literal, consume_string_literal,
+        skip_whitespace,
+    };
+    let p = skip_whitespace(source, pos);
+    if p >= source.len() {
+        return false; // empty paren — treat as Form A
+    }
+    if consume_string_literal(source, p).is_some() {
+        return true;
+    }
+    if consume_number_literal(source, p).is_some() {
+        return true;
+    }
+    if let Some((s, e)) = consume_ident(source, p) {
+        let word = &source[s..e];
+        // `null` / `true` / `false` are value literals; any
+        // other identifier is a column name (Form A).
+        return word.eq_ignore_ascii_case("null")
+            || word.eq_ignore_ascii_case("true")
+            || word.eq_ignore_ascii_case("false");
+    }
+    false // punctuation (e.g. `)`) — treat as Form A
+}
+
+const INSERT_PAREN_LIST: Node = Node::Lookahead(insert_first_paren);
 
 /// Schema-aware value list: when the walker has a populated
 /// `current_table_columns`, unfolds to a `Seq` of typed slots

src/dsl/grammar/mod.rs

@@ -286,9 +286,20 @@ pub enum Node {
         min: usize,
     },
     /// Resolves at walk time using the active `WalkContext`.
-    /// Phase D+ uses this for `column_value_list`.
+    /// Phase D+ uses this for `column_value_list`. The factory
+    /// is pure in `ctx`, so the walker memoizes the resolution
+    /// (one leak per distinct schema shape).
     #[allow(dead_code)]
     DynamicSubgrammar(fn(&WalkContext) -> Self),
+    /// Like `DynamicSubgrammar` but the factory also sees the
+    /// source and the current byte position, so it can look
+    /// ahead. Used by the insert first-paren to discriminate
+    /// Form A (`(cols) values (...)`) from Form C (`(vals)`)
+    /// before walking the contents — Form C then routes through
+    /// the typed `column_value_list` (ADR-0024 §Phase D, Form C
+    /// type-awareness). Not memoized: the output depends on the
+    /// source, not just `ctx`.
+    Lookahead(fn(&WalkContext, &str, usize) -> Self),
     /// Typed value-literal slot (ADR-0024 §Phase D §typed-value-slots).
     ///
     /// Walks `inner` to consume the literal but records the

src/dsl/walker/driver.rs

@@ -212,6 +212,20 @@ fn walk_node_inner(
             let resolved = resolve_dynamic(*factory, ctx);
             walk_node(source, pos, resolved, ctx, path, per_byte)
         }
+        Node::Lookahead(factory) => {
+            // ADR-0024 §Phase D Form-C type-awareness: the
+            // factory peeks the source at `pos` (e.g. to tell a
+            // Form A column list from a Form C value list) and
+            // returns the shape to walk. Not memoized — the
+            // result depends on the source — but the factory
+            // returns a small node (a Repeated, or a thin
+            // DynamicSubgrammar wrapper that delegates to the
+            // memoized `column_value_list`), so the per-walk
+            // leak is a few bytes, not a whole typed tree.
+            let resolved: &'static Node =
+                Box::leak(Box::new(factory(ctx, source, pos)));
+            walk_node(source, pos, resolved, ctx, path, per_byte)
+        }
         Node::TypedValueSlot {
             ty,
             column_name,

tests/typing_surface/insert_form_c.rs

@@ -1,24 +1,30 @@
 //! Matrix coverage for `insert into T (vals)` (Form C — bare
 //! value list, no `values` keyword).
 //!
-//! Form C shares the `( ... )` opener with Form A but resolves
+//! Form C and Form B produce the identical AST and dispatch
-//! the paren contents as values rather than column names. Per
+//! identically (`Insert { columns: None, … }`). As of the
-//! handoff-12 §2.2 the Form C path is *type-unaware* — its
+//! Form-C type-awareness work (handoff-14), Form C's paren is
-//! grammar uses the schemaless `INSERT_PAREN_LIST` shape, not
+//! resolved by the `insert_first_paren` lookahead: a value
-//! the typed `column_value_list`. Type validation happens at
+//! literal as the first token routes the contents through the
-//! bind time, not parse time.
+//! typed `column_value_list` — the same per-column typed slots
+//! Form B uses. So Form C values are now type-checked and
+//! count-checked at parse time, not only at bind time.
 //!
-//! The previous commit's Form C/A disambiguation means
+//! An identifier (column name) as the first token, or an empty
-//! column-shaped items (idents) inside the parens now flag as
+//! paren, routes to Form A instead — `insert into T (Name)`
-//! "did you mean Form A?". This file pins both the happy-path
+//! still surfaces the "did you mean Form A?" recovery.
-//! (literals only) and the Form-A-recovery (column-shaped
-//! items).
 
 use crate::typing_surface::*;
 use rdbms_playground::input_render::InputState;
 
+// =========================================================
+// Form C happy path: type-correct values parse to Insert.
+// =========================================================
+
 #[test]
-fn form_c_with_text_literals_parses() {
+fn form_c_text_pk_correct_values_parses() {
+    // Items(Code:text, Title:text) — Form C expects two text
+    // values (no auto-gen columns to skip).
     let schema = schema_text_pk();
     let a = assess_at_end(
         "insert into Items ('SKU-1', 'Widget')",
@@ -26,32 +32,128 @@ fn form_c_with_text_literals_parses() {
     );
     assert!(matches!(a.state, InputState::Valid));
     assert_eq!(a.parse_result.as_deref(), Ok("Insert"));
-    crate::snap!("form_c_text_literals", a);
+    crate::snap!("form_c_text_pk_valid", a);
 }
 
 #[test]
-fn form_c_with_mixed_literals_parses() {
+fn form_c_serial_pk_correct_values_parses() {
+    // Customers(id:serial, Name:text, Email:text) — Form C
+    // skips the serial `id`, expects two text values.
     let schema = schema_serial_pk();
     let a = assess_at_end(
-        "insert into Customers (1, 'Alice', 'a@b.c')",
+        "insert into Customers ('Alice', 'a@b.c')",
         &schema,
     );
     assert!(matches!(a.state, InputState::Valid));
     assert_eq!(a.parse_result.as_deref(), Ok("Insert"));
-    crate::snap!("form_c_mixed_literals", a);
+    crate::snap!("form_c_serial_pk_valid", a);
 }
 
 #[test]
-fn form_c_with_null_first_parses() {
+fn form_c_with_null_value_parses() {
+    // null is type-compatible with any slot.
     let schema = schema_serial_pk();
     let a = assess_at_end(
-        "insert into Customers (null, 'Alice', 'a@b.c')",
+        "insert into Customers (null, 'a@b.c')",
         &schema,
     );
     assert!(matches!(a.state, InputState::Valid));
-    crate::snap!("form_c_null_first", a);
+    crate::snap!("form_c_null_value", a);
 }
 
+// =========================================================
+// Form C is now type-aware (the §2.2 limitation is fixed).
+// =========================================================
+
+#[test]
+fn form_c_rejects_number_for_text_column() {
+    // `3.14` lands in the Name(text) slot — the typed slot
+    // rejects it at parse time. Before Form-C type-awareness
+    // this parsed Valid and only failed at bind time.
+    let schema = schema_serial_pk();
+    let a = assess_at_end(
+        "insert into Customers (3.14, 'a@b.c')",
+        &schema,
+    );
+    assert!(
+        !matches!(a.state, InputState::Valid),
+        "Form C should now type-check `3.14` against Name(text), got {:?}",
+        a.state,
+    );
+    crate::snap!("form_c_type_mismatch", a);
+}
+
+#[test]
+fn form_c_wrong_value_count_is_invalid() {
+    // Customers Form C expects exactly two values (id:serial
+    // skipped). Three values is a count mismatch — caught at
+    // parse time now.
+    let schema = schema_serial_pk();
+    let a = assess_at_end(
+        "insert into Customers ('Alice', 'a@b.c', 'extra')",
+        &schema,
+    );
+    assert!(
+        !matches!(a.state, InputState::Valid),
+        "Form C with too many values must be invalid, got {:?}",
+        a.state,
+    );
+    crate::snap!("form_c_wrong_count", a);
+}
+
+// =========================================================
+// Form C typed-slot prose — the per-column hint Form B has
+// is now available in Form C too.
+// =========================================================
+
+#[test]
+fn form_c_second_slot_shows_typed_prose_for_column() {
+    // First token `'Alice'` is a string literal → Form C. At
+    // the second slot the hint names the Email column.
+    let schema = schema_serial_pk();
+    let a = assess_at_end(
+        "insert into Customers ('Alice', ",
+        &schema,
+    );
+    let prose = hint_prose(&a).unwrap_or_else(|| {
+        panic!("expected Prose at Form C second slot, got {:?}", a.hint)
+    });
+    assert!(
+        prose.contains("Email"),
+        "Form C second slot should name `Email`, got prose: {prose:?}",
+    );
+    crate::snap!("form_c_typed_prose", a);
+}
+
+// =========================================================
+// In-progress Form C classifies as IncompleteAtEof.
+// =========================================================
+
+#[test]
+fn form_c_in_progress_after_comma_is_incomplete() {
+    let schema = schema_serial_pk();
+    let a = assess_at_end("insert into Customers ('Alice', ", &schema);
+    assert!(matches!(a.state, InputState::IncompleteAtEof));
+    crate::snap!("form_c_in_progress_after_comma", a);
+}
+
+#[test]
+fn form_c_in_progress_without_close_paren_is_incomplete() {
+    let schema = schema_serial_pk();
+    let a = assess_at_end(
+        "insert into Customers ('Alice', 'a@b.c'",
+        &schema,
+    );
+    assert!(matches!(a.state, InputState::IncompleteAtEof));
+    crate::snap!("form_c_in_progress_no_close", a);
+}
+
+// =========================================================
+// Form A recovery: a column-name identifier as the first
+// paren token routes to Form A — `insert into T (Name)`
+// without `values` flags as Form-A-in-progress.
+// =========================================================
+
 #[test]
 fn form_c_with_column_shaped_item_flags_as_form_a_in_progress() {
     let schema = schema_serial_pk();
@@ -73,37 +175,3 @@ fn form_c_with_two_columns_flags_as_form_a_in_progress() {
     assert_candidate_present(&a, &["values"]);
     crate::snap!("form_c_two_columns_recovery", a);
 }
-
-#[test]
-fn form_c_type_unaware_grammar_accepts_decimal_for_int_column() {
-    // Form C's grammar uses INSERT_PAREN_LIST (the pre-Phase-D
-    // schemaless choice), so type mismatches aren't caught at
-    // parse time. Bind time catches them. Handoff §2.2
-    // documents this as known.
-    let schema = schema_serial_pk();
-    let a = assess_at_end(
-        "insert into Customers (3.14, 'Alice', 'a@b.c')",
-        &schema,
-    );
-    assert!(matches!(a.state, InputState::Valid));
-    crate::snap!("form_c_type_unaware", a);
-}
-
-#[test]
-fn form_c_in_progress_after_comma_is_incomplete() {
-    let schema = schema_serial_pk();
-    let a = assess_at_end("insert into Customers (1, ", &schema);
-    assert!(matches!(a.state, InputState::IncompleteAtEof));
-    crate::snap!("form_c_in_progress_after_comma", a);
-}
-
-#[test]
-fn form_c_in_progress_without_close_paren_is_incomplete() {
-    let schema = schema_serial_pk();
-    let a = assess_at_end(
-        "insert into Customers (1, 'Alice'",
-        &schema,
-    );
-    assert!(matches!(a.state, InputState::IncompleteAtEof));
-    crate::snap!("form_c_in_progress_no_close", a);
-}

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_a__after_open_paren_offers_active_table_columns_only@after_open_paren_multi_table.snap

@@ -8,9 +8,19 @@ Assessment {
     cursor: 23,
     state: IncompleteAtEof,
     hint: Some(
-        Prose(
+        Candidates {
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            items: [
-        ),
+                Candidate {
+                    text: "Name",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "id",
+                    kind: Identifier,
+                },
+            ],
+            selected: None,
+        },
     ),
     completion: Some(
         Completion {
@@ -20,18 +30,6 @@ Assessment {
             ),
             partial_prefix: "",
             candidates: [
-                Candidate {
-                    text: "null",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
                 Candidate {
                     text: "Name",
                     kind: Identifier,

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_a__after_open_paren_serial_pk_offers_all_columns_including_serial@after_open_paren_serial_pk.snap

@@ -8,9 +8,23 @@ Assessment {
     cursor: 23,
     state: IncompleteAtEof,
     hint: Some(
-        Prose(
+        Candidates {
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            items: [
-        ),
+                Candidate {
+                    text: "Email",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "Name",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "id",
+                    kind: Identifier,
+                },
+            ],
+            selected: None,
+        },
     ),
     completion: Some(
         Completion {
@@ -20,18 +34,6 @@ Assessment {
             ),
             partial_prefix: "",
             candidates: [
-                Candidate {
-                    text: "null",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
                 Candidate {
                     text: "Email",
                     kind: Identifier,

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_a__after_open_paren_text_pk_offers_text_pk_columns@after_open_paren_text_pk.snap

@@ -8,9 +8,19 @@ Assessment {
     cursor: 19,
     state: IncompleteAtEof,
     hint: Some(
-        Prose(
+        Candidates {
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            items: [
-        ),
+                Candidate {
+                    text: "Code",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "Title",
+                    kind: Identifier,
+                },
+            ],
+            selected: None,
+        },
     ),
     completion: Some(
         Completion {
@@ -20,18 +30,6 @@ Assessment {
             ),
             partial_prefix: "",
             candidates: [
-                Candidate {
-                    text: "null",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
                 Candidate {
                     text: "Code",
                     kind: Identifier,

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_a__form_a_open_paren_no_leakage_from_other_tables@form_a_open_paren_orders.snap

@@ -8,9 +8,23 @@ Assessment {
     cursor: 20,
     state: IncompleteAtEof,
     hint: Some(
-        Prose(
+        Candidates {
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            items: [
-        ),
+                Candidate {
+                    text: "CustId",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "OrderId",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "Total",
+                    kind: Identifier,
+                },
+            ],
+            selected: None,
+        },
     ),
     completion: Some(
         Completion {
@@ -20,18 +34,6 @@ Assessment {
             ),
             partial_prefix: "",
             candidates: [
-                Candidate {
-                    text: "null",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
                 Candidate {
                     text: "CustId",
                     kind: Identifier,

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_a__mid_column_list_after_comma_offers_remaining_columns@after_comma_in_column_list.snap

@@ -8,9 +8,23 @@ Assessment {
     cursor: 27,
     state: IncompleteAtEof,
     hint: Some(
-        Prose(
+        Candidates {
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            items: [
-        ),
+                Candidate {
+                    text: "Email",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "Name",
+                    kind: Identifier,
+                },
+                Candidate {
+                    text: "id",
+                    kind: Identifier,
+                },
+            ],
+            selected: None,
+        },
     ),
     completion: Some(
         Completion {
@@ -20,18 +34,6 @@ Assessment {
             ),
             partial_prefix: "",
             candidates: [
-                Candidate {
-                    text: "null",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
                 Candidate {
                     text: "Email",
                     kind: Identifier,

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_in_progress_after_comma_is_incomplete@form_c_in_progress_after_comma.snap

@@ -1,22 +1,22 @@
 ---
 source: tests/typing_surface/insert_form_c.rs
-description: "input=\"insert into Customers (1, \" cursor=26"
+description: "input=\"insert into Customers ('Alice', \" cursor=32"
 expression: "& a"
 ---
 Assessment {
-    input: "insert into Customers (1, ",
+    input: "insert into Customers ('Alice', ",
-    cursor: 26,
+    cursor: 32,
     state: IncompleteAtEof,
     hint: Some(
         Prose(
-            "Type a value: number, 'text', true/false, null (dates as 'YYYY-MM-DD', datetimes as 'YYYY-MM-DDTHH:MM:SS')",
+            "for `Email`: Type a quoted string (e.g. 'Alice') or null",
         ),
     ),
     completion: Some(
         Completion {
             replaced_range: (
-                26,
+                32,
-                26,
+                32,
             ),
             partial_prefix: "",
             candidates: [
@@ -24,26 +24,6 @@ Assessment {
                     text: "null",
                     kind: Keyword,
                 },
-                Candidate {
-                    text: "true",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "false",
-                    kind: Keyword,
-                },
-                Candidate {
-                    text: "Email",
-                    kind: Identifier,
-                },
-                Candidate {
-                    text: "Name",
-                    kind: Identifier,
-                },
-                Candidate {
-                    text: "id",
-                    kind: Identifier,
-                },
             ],
         },
     ),

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_in_progress_without_close_paren_is_incomplete@form_c_in_progress_no_close.snap

@@ -1,11 +1,11 @@
 ---
 source: tests/typing_surface/insert_form_c.rs
-description: "input=\"insert into Customers (1, 'Alice'\" cursor=33"
+description: "input=\"insert into Customers ('Alice', 'a@b.c'\" cursor=39"
 expression: "& a"
 ---
 Assessment {
-    input: "insert into Customers (1, 'Alice'",
+    input: "insert into Customers ('Alice', 'a@b.c'",
-    cursor: 33,
+    cursor: 39,
     state: IncompleteAtEof,
     hint: Some(
         Prose(

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_rejects_number_for_text_column@form_c_type_mismatch.snap

@@ -0,0 +1,35 @@
+---
+source: tests/typing_surface/insert_form_c.rs
+description: "input=\"insert into Customers (3.14, 'a@b.c')\" cursor=37"
+expression: "& a"
+---
+Assessment {
+    input: "insert into Customers (3.14, 'a@b.c')",
+    cursor: 37,
+    state: DefiniteErrorAt(
+        23,
+    ),
+    hint: Some(
+        Prose(
+            "for `Name`: Type a quoted string (e.g. 'Alice') or null (`id` auto-generated — skipped here; list columns explicitly, e.g. `insert into T (...) values (...)`, to set it.)",
+        ),
+    ),
+    completion: Some(
+        Completion {
+            replaced_range: (
+                37,
+                37,
+            ),
+            partial_prefix: "",
+            candidates: [
+                Candidate {
+                    text: "null",
+                    kind: Keyword,
+                },
+            ],
+        },
+    ),
+    parse_result: Err(
+        "Invalid(definite)",
+    ),
+}

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_second_slot_shows_typed_prose_for_column@form_c_typed_prose.snap

@@ -0,0 +1,33 @@
+---
+source: tests/typing_surface/insert_form_c.rs
+description: "input=\"insert into Customers ('Alice', \" cursor=32"
+expression: "& a"
+---
+Assessment {
+    input: "insert into Customers ('Alice', ",
+    cursor: 32,
+    state: IncompleteAtEof,
+    hint: Some(
+        Prose(
+            "for `Email`: Type a quoted string (e.g. 'Alice') or null",
+        ),
+    ),
+    completion: Some(
+        Completion {
+            replaced_range: (
+                32,
+                32,
+            ),
+            partial_prefix: "",
+            candidates: [
+                Candidate {
+                    text: "null",
+                    kind: Keyword,
+                },
+            ],
+        },
+    ),
+    parse_result: Err(
+        "Invalid(at_eof)",
+    ),
+}

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_serial_pk_correct_values_parses@form_c_serial_pk_valid.snap

@@ -1,11 +1,11 @@
 ---
 source: tests/typing_surface/insert_form_c.rs
-description: "input=\"insert into Customers (1, 'Alice', 'a@b.c')\" cursor=43"
+description: "input=\"insert into Customers ('Alice', 'a@b.c')\" cursor=40"
 expression: "& a"
 ---
 Assessment {
-    input: "insert into Customers (1, 'Alice', 'a@b.c')",
+    input: "insert into Customers ('Alice', 'a@b.c')",
-    cursor: 43,
+    cursor: 40,
     state: Valid,
     hint: Some(
         Candidates {
@@ -21,8 +21,8 @@ Assessment {
     completion: Some(
         Completion {
             replaced_range: (
-                43,
+                40,
-                43,
+                40,
             ),
             partial_prefix: "",
             candidates: [

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_with_null_first_parses@form_c_null_first.snap

@@ -1,39 +0,0 @@
----
-source: tests/typing_surface/insert_form_c.rs
-description: "input=\"insert into Customers (null, 'Alice', 'a@b.c')\" cursor=46"
-expression: "& a"
----
-Assessment {
-    input: "insert into Customers (null, 'Alice', 'a@b.c')",
-    cursor: 46,
-    state: Valid,
-    hint: Some(
-        Candidates {
-            items: [
-                Candidate {
-                    text: "values",
-                    kind: Keyword,
-                },
-            ],
-            selected: None,
-        },
-    ),
-    completion: Some(
-        Completion {
-            replaced_range: (
-                46,
-                46,
-            ),
-            partial_prefix: "",
-            candidates: [
-                Candidate {
-                    text: "values",
-                    kind: Keyword,
-                },
-            ],
-        },
-    ),
-    parse_result: Ok(
-        "Insert",
-    ),
-}

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_with_null_value_parses@form_c_null_value.snap

@@ -1,11 +1,11 @@
 ---
 source: tests/typing_surface/insert_form_c.rs
-description: "input=\"insert into Customers (3.14, 'Alice', 'a@b.c')\" cursor=46"
+description: "input=\"insert into Customers (null, 'a@b.c')\" cursor=37"
 expression: "& a"
 ---
 Assessment {
-    input: "insert into Customers (3.14, 'Alice', 'a@b.c')",
+    input: "insert into Customers (null, 'a@b.c')",
-    cursor: 46,
+    cursor: 37,
     state: Valid,
     hint: Some(
         Candidates {
@@ -21,8 +21,8 @@ Assessment {
     completion: Some(
         Completion {
             replaced_range: (
-                46,
+                37,
-                46,
+                37,
             ),
             partial_prefix: "",
             candidates: [

tests/typing_surface/snapshots/typing_surface_matrix__typing_surface__insert_form_c__form_c_wrong_value_count_is_invalid@form_c_wrong_count.snap

@@ -0,0 +1,21 @@
+---
+source: tests/typing_surface/insert_form_c.rs
+description: "input=\"insert into Customers ('Alice', 'a@b.c', 'extra')\" cursor=49"
+expression: "& a"
+---
+Assessment {
+    input: "insert into Customers ('Alice', 'a@b.c', 'extra')",
+    cursor: 49,
+    state: DefiniteErrorAt(
+        39,
+    ),
+    hint: Some(
+        Prose(
+            "Submit with Enter",
+        ),
+    ),
+    completion: None,
+    parse_result: Err(
+        "Invalid(definite)",
+    ),
+}