Initial project import

tools/v/vlib/x/json2/attr_utils.v

@@ -0,0 +1,54 @@
+module json2
+
+@[inline]
+fn unquote_attr_value(value string) string {
+	mut unquoted := value.trim_space()
+	if unquoted.len > 1 {
+		if (unquoted[0] == `'` && unquoted[unquoted.len - 1] == `'`)
+			|| (unquoted[0] == `"` && unquoted[unquoted.len - 1] == `"`) {
+			unquoted = unquoted[1..unquoted.len - 1]
+		}
+	}
+	return unquoted
+}
+
+@[inline]
+fn json_attr_value(attr string) ?string {
+	if !attr.starts_with('json:') {
+		return none
+	}
+	return unquote_attr_value(attr[5..])
+}
+
+@[markused]
+fn json_attr_value_range(attr string) ?(int, int) {
+	if !attr.starts_with('json:') {
+		return none
+	}
+	mut start := 5
+	for start < attr.len && attr[start] in [` `, `\t`, `\n`, `\r`] {
+		start++
+	}
+	mut end := attr.len
+	for end > start && attr[end - 1] in [` `, `\t`, `\n`, `\r`] {
+		end--
+	}
+	if end - start > 1 {
+		if (attr[start] == `'` && attr[end - 1] == `'`)
+			|| (attr[start] == `"` && attr[end - 1] == `"`) {
+			start++
+			end--
+		}
+	}
+	return start, end
+}
+
+@[inline]
+fn enum_uses_json_as_number[T]() bool {
+	$for attr in T.attributes {
+		if attr.name == 'json_as_number' {
+			return true
+		}
+	}
+	return false
+}