From 92cc395e2eee1e0d7e051775a795e5f83e45c5e9 Mon Sep 17 00:00:00 2001
From: Kai Stevenson <kai@kaistevenson.com>
Date: Sun, 9 Nov 2025 13:29:28 -0800
Subject: wip error handling

---
 src/lang/ts-lang/core/common.ts |  5 +++++
 src/lang/ts-lang/core/eval.ts   | 17 ++++++++++-------
 src/lang/ts-lang/core/lexer.ts  |  5 ++++-
 src/lang/ts-lang/core/parser.ts | 30 +++++++++++++++++++-----------
 4 files changed, 38 insertions(+), 19 deletions(-)

(limited to 'src')

diff --git a/src/lang/ts-lang/core/common.ts b/src/lang/ts-lang/core/common.ts
index 0287eec..8d08e05 100644
--- a/src/lang/ts-lang/core/common.ts
+++ b/src/lang/ts-lang/core/common.ts
@@ -68,3 +68,8 @@ export type MergeStackFrames<
     ? NewFrame["bindings"][K]
     : OldFrame["bindings"][K];
 }>;
+
+export type KSError<Message extends string = string> = {
+  __KS_ERROR: true;
+  message: Message;
+};
diff --git a/src/lang/ts-lang/core/eval.ts b/src/lang/ts-lang/core/eval.ts
index ebc58e7..fa11f3c 100644
--- a/src/lang/ts-lang/core/eval.ts
+++ b/src/lang/ts-lang/core/eval.ts
@@ -1,3 +1,4 @@
+import { AnySoaRecord } from "dns";
 import {
   BUILTIN_Add,
   BUILTIN_Arr,
@@ -13,11 +14,15 @@ import { ToString } from "../util";
 import {
   ASTNode,
   EmptyStackFrame,
+  KSError,
   MergeStackFrames,
   NodeType,
   StackFrame,
 } from "./common";
 
+export type EvalError<Message extends string> =
+  KSError<`Eval error: ${Message}`>;
+
 export type RECURSION_DEPTH_LIMIT = 7;
 
 export type SENTINEL_NO_BUILTIN = "__NO_BUILTIN__";
@@ -51,8 +56,6 @@ export type MapBuiltins<
     : SENTINEL_NO_BUILTIN
   : never;
 
-export type EvalError<T extends string> = `Eval error: ${T}`;
-
 export type FindInStack<
   Frame extends StackFrame,
   NameToFind
@@ -168,8 +171,8 @@ export type GetEvaluatedChildren<
     }
   : never;
 
-export type Evaluate<Node extends ASTNode> = _Evaluate<
-  Node,
-  EmptyStackFrame,
-  []
->;
+export type Evaluate<Node> = Node extends ASTNode
+  ? _Evaluate<Node, EmptyStackFrame, []>
+  : Node extends KSError<infer E>
+  ? E
+  : EvalError<`Cannot evaluate ${ToString<Node>}`>;
diff --git a/src/lang/ts-lang/core/lexer.ts b/src/lang/ts-lang/core/lexer.ts
index bcd5785..71a63a6 100644
--- a/src/lang/ts-lang/core/lexer.ts
+++ b/src/lang/ts-lang/core/lexer.ts
@@ -1,4 +1,7 @@
-import { LexerCtx, Token, TokenType } from "./common";
+import { KSError, LexerCtx, Token, TokenType } from "./common";
+
+export type LexerError<Message extends string = string> =
+  KSError<`Lexer error: ${Message}`>;
 
 export type IsWhitespace<T extends string> = T extends `${TokenType.SPACE}`
   ? true
diff --git a/src/lang/ts-lang/core/parser.ts b/src/lang/ts-lang/core/parser.ts
index 3a497a2..fd40e63 100644
--- a/src/lang/ts-lang/core/parser.ts
+++ b/src/lang/ts-lang/core/parser.ts
@@ -1,11 +1,14 @@
-import { ASTNode, NodeType, ParserCtx, Token, TokenType } from "./common";
+import {
+  ASTNode,
+  KSError,
+  NodeType,
+  ParserCtx,
+  Token,
+  TokenType,
+} from "./common";
 
-export type Error<T extends string> = ASTNode<
-  NodeType.PARSER_ERROR,
-  "Error",
-  T,
-  []
->;
+export type ParserError<Message extends string> =
+  KSError<`Parser error: ${Message}`>;
 
 export type PushChild<Node extends ASTNode, Child extends ASTNode> = {
   type: Node["type"];
@@ -129,7 +132,7 @@ export type _Parse<Ctx extends ParserCtx> = Ctx["remainingTokens"] extends [
           remainingTokens: Tail;
           stack: [...Ctx["stack"], ResolveNodeFromToken<Ctx["lastToken"]>];
         }>
-      : Ctx & Error<`Was not expecting ${Head["type"]}`>
+      : ParserError<`Was not expecting ${Head["type"]}`>
     : // expect nextToken to be a name or close paren
     Head["type"] extends TokenType.NAME
     ? // lastToken = nextToken
@@ -152,8 +155,7 @@ export type _Parse<Ctx extends ParserCtx> = Ctx["remainingTokens"] extends [
           >
         >;
       }>
-    : Ctx &
-        Error<`Expected nextToken to be a name or close paren at ${Head["type"]}`>
+    : ParserError<`Expected nextToken to be a name or close paren at ${Head["type"]}`>
   : Ctx["lastToken"] extends Token
   ? // case where we ended with a name
     _Parse<{
@@ -170,4 +172,10 @@ export type Parse<Raw extends readonly Token[]> = _Parse<{
   lastToken: null;
   remainingTokens: Raw;
   stack: [ASTNode<NodeType.EXT, "arr", null, []>];
-}>;
+}> extends infer P
+  ? P extends ASTNode
+    ? P
+    : P extends KSError<infer E>
+    ? E
+    : never
+  : never;
-- 
cgit v1.2.3-70-g09d2