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silverbullet/common/markdown_parser/parse_tree.ts
2023-01-01 11:28:25 -08:00

67 lines
1.6 KiB
TypeScript

import type { ParseTree } from "$sb/lib/tree.ts";
import type { Language, SyntaxNode } from "../deps.ts";
export function lezerToParseTree(
text: string,
n: SyntaxNode,
offset = 0,
): ParseTree {
let children: ParseTree[] = [];
let nodeText: string | undefined;
let child = n.firstChild;
while (child) {
children.push(lezerToParseTree(text, child));
child = child.nextSibling;
}
if (children.length === 0) {
children = [
{
from: n.from + offset,
to: n.to + offset,
text: text.substring(n.from, n.to),
},
];
} else {
const newChildren: ParseTree[] = [];
let index = n.from;
for (const child of children) {
const s = text.substring(index, child.from);
if (s) {
newChildren.push({
from: index + offset,
to: child.from! + offset,
text: s,
});
}
newChildren.push(child);
index = child.to!;
}
const s = text.substring(index, n.to);
if (s) {
newChildren.push({ from: index + offset, to: n.to + offset, text: s });
}
children = newChildren;
}
const result: ParseTree = {
type: n.name,
from: n.from + offset,
to: n.to + offset,
};
if (children.length > 0) {
result.children = children;
}
if (nodeText) {
result.text = nodeText;
}
return result;
}
export function parse(language: Language, text: string): ParseTree {
// Remove \r for Windows before parsing
text = text.replaceAll("\r", "");
const tree = lezerToParseTree(text, language.parser.parse(text).topNode);
return tree;
}