hare-xdg/format/desktop_entry/parse.ha

118 lines
2.9 KiB
Hare

use bufio;
use encoding::utf8;
use io;
use locale;
use memio;
use strings;
// Parses a [[file]]. The result must be freed using [[file_finish]].
export fn file_parse(in: io::stream) !(file | error | io::error | utf8::invalid) = {
let scanner = bufio::newscanner(&in);
defer bufio::finish(&scanner);
let fil = file { ... };
for (true) {
let text = match (bufio::scan_line(&scanner)) {
case let text: const str =>
yield text;
case let err: io::EOF =>
break;
case let err: (io::error | utf8::invalid) =>
file_finish(&fil);
return err;
};
if (text == "") {
// blank line
file_append_line(&fil, blank);
} else if (strings::hasprefix(text, '#')) {
// comment
let text = strings::dup(strings::ltrim(text, '#'));
file_append_line(&fil, text: comment);
} else if (strings::hasprefix(text, '[')) {
// group header
let name = strings::dup(parse_group_header(text)?);
file_append_group(&fil, name);
} else {
// key/value pair
let (key, valu, local) = match (parse_entry(text)) {
case let result: (str, str, (locale::locale | void)) =>
yield result;
case let err: error =>
file_finish(&fil);
return err;
};
file_append_line(&fil, match (local) {
case let local: locale::locale =>
yield localized_entry {
key = key,
value = valu,
locale = local,
};
case void =>
yield entry {
key = key,
value = valu,
};
});
};
};
return fil;
};
fn file_append_line(fil: *file, lin: line) void = {
if (len(fil.groups) > 0) {
append(fil.groups[len(fil.groups) - 1].lines, lin);
} else {
append(fil.preceeding_lines, lin);
};
};
// memory is borrowed from the input
fn parse_group_header(text: str) (str | error) = {
if (!strings::hasprefix(text, '[') || !strings::hassuffix(text, ']')) {
return invalid_group_header;
};
text = strings::rtrim(strings::ltrim(text, '['), ']');
if (strings::contains(text, '[', ']')) {
return invalid_group_header;
};
return text;
};
// memory must be freed by the caller
fn parse_entry(line: str) ((str, str, (locale::locale | void)) | error) = {
if (!strings::contains(line, '=')) return invalid_entry;
let (key, valu) = strings::cut(line, "=");
key = strings::ltrim(strings::rtrim(key));
if (!validate_entry_key(key)) return invalid_entry;
let local: (locale::locale | void) = void;
let (key, local_string) = strings::cut(key, "[");
if (local_string != "") {
local_string = locale(strings::rtrim(local, "]"));
if (!validate_entry_locale(local_string)) return invalid_entry;
local = match(local_string) {
case let local: locale::locale => yield local;
case errors::invalid => return invalid_entry;
};
};
return (strings::dup(key), strings::dup(valu), local);
};
fn validate_entry_key(key: str) bool = {
return strings::contains(key, '[', ']', '=');
};
fn validate_entry_locale(key: str) bool = {
return strings::contains(key, '[', ']', '=');
};