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Change record syntax, fix a few bugs

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This commit is contained in:
Yura Dupyn 2026-02-06 21:52:32 +01:00
parent 13a66f2d16
commit e389e46852
7 changed files with 212 additions and 114 deletions
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70
src/parser/scanner.ts
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@ -47,7 +47,7 @@ const DELIMITER_CHARS = ["(", ")", "{", "}", ".", ",", "@", "$", "#", '"', "\\"]
export type Delimiter = typeof DELIMITER_CHARS[number];
const DELIMITER_SET: Set<CodePoint> = new Set(DELIMITER_CHARS.map(c => char(c)));
const KEYWORD_LIST = ["let" , "fn" , "match" , "apply" , "=" , "|" , "!"] as const;
const KEYWORD_LIST = ["let" , "fn" , "match" , "apply" , "=" , "|" , "!", ":"] as const;
export type Keyword = typeof KEYWORD_LIST[number];
const KEYWORD_SET: Set<string> = new Set(KEYWORD_LIST);
@ -61,13 +61,14 @@ export type ExprScanError =
// What kind of identifier were we trying to parse?
export type IdentifierKind =
| "identifier"
| "variable_use"
| "field_name"
| "tag_construction"
| "function_call"
| "pattern_binding";
export type IdentifierErrorReason =
| { tag: "Empty" }
| { tag: "StartsWithDigit" }
| { tag: "IsKeyword", kw: Keyword }
@ -80,7 +81,6 @@ export type ExprStartToken =
| { tag: "variable_use", name: string, span: Span }
| { tag: "tag", name: string, span: Span }
| { tag: "tuple_start", span: Span }
| { tag: "record_start", span: Span }
| { tag: "keyword", kw: Keyword, span: Span }
// TODO: ger rid of EOF
| { tag: "EOF", span: Span }
@ -89,7 +89,7 @@ export type PatternStartToken =
| { tag: "pattern_binding", name: string, span: Span }
| { tag: "tag", name: string, span: Span }
| { tag: "tuple_start", span: Span }
| { tag: "record_start", span: Span }
| { tag: "keyword", kw: Keyword, span: Span }
// TODO: ger rid of EOF
| { tag: "EOF", span: Span };
@ -116,7 +116,7 @@ function rawIdentifier(cursor: Cursor): string {
// Scans raw identifier,
// checks if it is a keyword,
// if it ain't, validates it into a proper identifier.
function identifierOrKeyword(
function identifierOrKeywordScanner(
cursor: Cursor,
kind: IdentifierKind,
): { tag: "keyword", kw: Keyword, span: Span }
@ -124,6 +124,15 @@ function identifierOrKeyword(
const start = cursor.currentLocation();
const text = rawIdentifier(cursor);
const span = cursor.makeSpan(start);
if (text.length === 0) {
throw ({
tag: "InvalidIdentifier",
text,
kind,
reason: { tag: "Empty" },
span
} as ExprScanError);
}
if (KEYWORD_SET.has(text)) {
return { tag: "keyword", kw: text as Keyword, span };
@ -142,8 +151,8 @@ function identifierOrKeyword(
return { tag: "identifier", name: text, span };
}
export function identifier(cursor: Cursor, kind: IdentifierKind): { name: string, span: Span } {
const res = identifierOrKeyword(cursor, kind);
export function identifierScanner(cursor: Cursor, kind: IdentifierKind): { name: string, span: Span } {
const res = identifierOrKeywordScanner(cursor, kind);
if (res.tag === "keyword") {
throw ({
@ -201,14 +210,14 @@ export function exprStart(cursor: Cursor): ExprStartToken {
// === variable use ===
if (c === char('$')) {
cursor.next();
const { name } = identifier(cursor, 'variable_use');
const { name } = identifierScanner(cursor, 'variable_use');
return { tag: "variable_use", name, span: cursor.makeSpan(start) };
}
// === tags ===
if (c === char('#')) {
cursor.next();
const { name } = identifier(cursor, 'tag_construction');
const { name } = identifierScanner(cursor, 'tag_construction');
return { tag: "tag", name, span: cursor.makeSpan(start) };
}
@ -219,15 +228,9 @@ export function exprStart(cursor: Cursor): ExprStartToken {
return { tag: "tuple_start", span: cursor.makeSpan(start) };
}
// === records ===
if (c === char('{')) {
cursor.next();
return { tag: "record_start", span: cursor.makeSpan(start) };
}
// === keywords & identifiers ===
// Fallthrough: it must be a keyword or a function call
const result = identifierOrKeyword(cursor, 'function_call');
const result = identifierOrKeywordScanner(cursor, 'function_call');
switch (result.tag) {
case "keyword":
return result;
@ -250,16 +253,10 @@ export function patternStart(cursor: Cursor): PatternStartToken {
return { tag: "tuple_start", span: cursor.makeSpan(start) };
}
// === record ===
if (c === char('{')) {
cursor.next();
return { tag: "record_start", span: cursor.makeSpan(start) };
}
// === tag ===
if (c === char('#')) {
cursor.next();
const { name } = identifier(cursor, 'tag_construction');
const { name } = identifierScanner(cursor, 'tag_construction');
return { tag: "tag", name, span: cursor.makeSpan(start) };
}
@ -274,8 +271,14 @@ export function patternStart(cursor: Cursor): PatternStartToken {
}
// === pattern binding ===
const { name } = identifier(cursor, 'pattern_binding');
return { tag: "pattern_binding", name, span: cursor.makeSpan(start) };
// Fallthrough: it must be a keyword or a pattern-variable
const result = identifierOrKeywordScanner(cursor, 'function_call');
switch (result.tag) {
case "keyword":
return result;
case "identifier":
return { tag: "pattern_binding", name: result.name, span: result.span };
}
}
export function isNextTokenExprStart(cursor: Cursor): boolean {
@ -289,7 +292,6 @@ export function isNextTokenExprStart(cursor: Cursor): boolean {
case "variable_use":
case "tag":
case "tuple_start":
case "record_start":
case "function_name": // e.g. my_func(x)
return true;
@ -299,6 +301,7 @@ export function isNextTokenExprStart(cursor: Cursor): boolean {
case "fn":
case "match":
case "apply":
case ":":
return true;
case "=":
case "|":
@ -327,8 +330,21 @@ export function isNextTokenProductPatternStart(cursor: Cursor): boolean {
switch (token.tag) {
case "pattern_binding":
case "tuple_start":
case "record_start":
return true;
case "keyword":
switch (token.kw) {
case ":":
return true;
case "let":
case "fn":
case "match":
case "apply":
case "=":
case "|":
case "!":
return false;
}
default:
return false;
}