Implemented basic-tree

source/data/string-utilities.mjs

@@ -0,0 +1,51 @@
+import * as CF from '@efforting.tech/data/field-configuration-factories';
+
+
+export const Indention_Mode = new CF.symbol_set({
+	AUTO: 'Automatic detection of indention mode',
+	SPACES: 'Indention is based on spaces',
+	TABULATORS: 'Indention is based on tabulators',
+}, 'Indention mode');
+
+
+// BUG: Current implementation of CF.symbol_set doesn't support default value
+export const Text_Settings = new CF.Schema({
+	indention_mode: Indention_Mode,
+	indention_tabulator_width: CF.cardinal_value(4, 'Width of a tabulator in spaces'),
+	first_line: CF.natural_value(1, 'First line number'),
+}, 'Text settings');
+
+
+export function string_has_contents(str) {
+	return /\S/.test(str);
+}
+
+
+export function *indented_line_iterator(settings, text) {
+	let line_no = settings.first_line;
+	let index = 0;
+	const { indention_tabulator_width } = settings;
+
+	switch (settings.indention_mode) {
+		case Indention_Mode.symbols.TABULATORS: {
+			for (const line of text.matchAll(/^(\t*)(.*)$/gm)) {
+				const [raw, tabs, remaining] = line;
+				yield { raw, indent: tabs.length, line: remaining, line_no: line_no++, index: index++};
+			}
+			break;
+		}
+		case Indention_Mode.symbols.SPACES: {
+			for (const line of text.matchAll(/^([ ]*)(.*)$/gm)) {
+				const [raw, spaces, remaining] = line;
+
+				if ((spaces.length % indention_tabulator_width) !== 0) {
+					throw new Error('Unaligned indention');	//TODO - proper error
+				}
+				yield { raw, indent: Math.floor(spaces.length / indention_tabulator_width), line: remaining, line_no: line_no++, index: index++};
+			}
+			break;
+		}
+		default:
+			throw new Error('Unsupported indention mode');	//TODO - proper error
+	}
+}