Better errors!

src/ast.ts

@@ -5,16 +5,25 @@ import type { Value } from './types';
 export type Literal = {
     kind: 'literal'
     value: Value
+    line: number
+    column: number
+    start: number
 }
 
 export type Variable = {
     kind: 'variable'
     name: string
+    line: number
+    column: number
+    start: number
 }
 
 export type Constructor = {
     kind: 'constructor'
     name: string
+    line: number
+    column: number
+    start: number
 }
 
 // Functions
@@ -23,12 +32,18 @@ export type Lambda = {
     kind: 'lambda'
     params: string[]
     body: AST
+    line: number
+    column: number
+    start: number
 }
 
 export type Apply = {
     kind: 'apply'
     func: AST
     args: AST[]
+    line: number
+    column: number
+    start: number
 }
 
 // Bindings
@@ -38,6 +53,9 @@ export type Let = {
     name: string
     value: AST
     body: AST
+    line: number
+    column: number
+    start: number
 }
 
 // Matching
@@ -46,11 +64,17 @@ export type Match = {
     kind: 'match'
     expr: AST
     cases: MatchCase[]
+    line: number
+    column: number
+    start: number
 }
 
 export type MatchCase = {
     pattern: Pattern
     result: AST
+    line: number
+    column: number
+    start: number
 }
 
 export type Pattern =
@@ -64,26 +88,46 @@ export type Pattern =
 
 // Data Structures
 
+export type ListSpread = {
+    kind: 'list-spread'
+    spread: AST;
+    line: number;
+    column: number;
+    start: number;
+}
+
 export type List = {
     kind: 'list'
-    elements: (AST | { spread: AST })[]
+    elements: (AST | ListSpread)[]
+    line: number
+    column: number
+    start: number
 }
 
 export type Record = {
     kind: 'record'
     fields: { [key: string]: AST }
+    line: number
+    column: number
+    start: number
 }
 
 export type RecordAccess = {
     kind: 'record-access'
     record: AST
     field: string
+    line: number
+    column: number
+    start: number
 }
 
 export type RecordUpdate = {
     kind: 'record-update'
     record: AST
     updates: { [key: string]: AST }
+    line: number
+    column: number
+    start: number
 }
 
 // Top-level constructs
@@ -92,19 +136,27 @@ export type Definition = {
     kind: 'definition'
     name: string
     body: AST
-    // type?: string // TODO
+    line: number
+    column: number
+    start: number
 }
 
 export type TypeDef = {
     kind: 'typedef'
     name: string
     variants: Array<{ name: string, args: string[] }>
+    line: number
+    column: number
+    start: number
 }
 
 export type Import = {
     kind: 'import'
     module: string
     items: string[] | 'all'
+    line: number
+    column: number
+    start: number
 }
 
 export type AST =
@@ -119,6 +171,7 @@ export type AST =
     | RecordAccess
     | RecordUpdate
     | List
+    | ListSpread
     | Definition
     | TypeDef
     | Import
@@ -183,7 +236,7 @@ export function prettyPrint(ast: AST, indent = 0): string {
             return `${i}match ${expr}\n${cases}`;
 
         default:
-            return `${i}${ast.kind}`
+            return `Unknown AST kind: ${i}${(ast as any).kind}`
     }
 }
 
@@ -215,5 +268,7 @@ function prettyPrintPattern(pattern: Pattern): string {
                 .join(', ');
 
             return `{${fields}}`;
+        default:
+            return `Unknown AST kind: ${(pattern as any).kind}`
     }
 }