platform/packages/route/lib/src/grammar.dart
2024-09-22 18:46:14 -07:00

327 lines
8.2 KiB
Dart

part of 'router.dart';
class RouteGrammar {
static const String notSlashRgx = r'([^/]+)';
//static final RegExp rgx = RegExp(r'\((.+)\)');
static final Parser<String> notSlash =
match<String>(RegExp(notSlashRgx)).value((r) => r.span?.text ?? '');
static final Parser<Match> regExp =
match<Match>(RegExp(r'\(([^\n)]+)\)([^/]+)?'))
.value((r) => r.scanner.lastMatch!);
static final Parser<Match> parameterName =
match<Match>(RegExp('$notSlashRgx?' r':([A-Za-z0-9_]+)' r'([^(/\n])?'))
.value((r) => r.scanner.lastMatch!);
static final Parser<ParameterSegment> parameterSegment = chain([
parameterName,
match<bool>('?').value((r) => true).opt(),
regExp.opt(),
]).map((r) {
var match = r.value![0] as Match;
var r2 = r.value![2];
Match? rgxMatch;
if (r2 != 'NULL') {
rgxMatch = r2 as Match?;
}
var pre = match[1] ?? '';
var post = match[3] ?? '';
RegExp? rgx;
if (rgxMatch != null) {
rgx = RegExp('(${rgxMatch[1]})');
post = (rgxMatch[2] ?? '') + post;
}
if (pre.isNotEmpty || post.isNotEmpty) {
if (rgx != null) {
var pattern = pre + rgx.pattern + post;
rgx = RegExp(pattern);
} else {
rgx = RegExp('$pre$notSlashRgx$post');
}
}
// TODO: relook at this later
var m2 = match[2] ?? '';
var s = ParameterSegment(m2, rgx);
return r.value![1] == true ? OptionalSegment(s) : s;
});
static final Parser<ParsedParameterSegment> parsedParameterSegment = chain([
match(RegExp(r'(int|num|double)'),
errorMessage: 'Expected "int","double", or "num".')
.map((r) => r.span!.text),
parameterSegment,
]).map((r) {
return ParsedParameterSegment(
r.value![0] as String, r.value![1] as ParameterSegment);
});
static final Parser<WildcardSegment> wildcardSegment =
match<WildcardSegment>(RegExp('$notSlashRgx?' r'\*' '$notSlashRgx?'))
.value((r) {
var m = r.scanner.lastMatch!;
var pre = m[1] ?? '';
var post = m[2] ?? '';
return WildcardSegment(pre, post);
});
static final Parser<ConstantSegment> constantSegment =
notSlash.map<ConstantSegment>((r) => ConstantSegment(r.value));
static final Parser<SlashSegment> slashSegment =
match(SlashSegment.rgx).map((_) => SlashSegment());
static final Parser<RouteSegment> routeSegment = any([
//slashSegment,
parsedParameterSegment,
parameterSegment,
wildcardSegment,
constantSegment
]);
// static final Parser<RouteDefinition> routeDefinition = routeSegment
// .star()
// .map<RouteDefinition>((r) => RouteDefinition(r.value ?? []))
// .surroundedBy(match(RegExp(r'/*')).opt());
static final Parser slashes = match(RegExp(r'/*'));
static final Parser<RouteDefinition> routeDefinition = routeSegment
.separatedBy(slashes)
.map<RouteDefinition>((r) => RouteDefinition(r.value ?? []))
.surroundedBy(slashes.opt());
}
class RouteDefinition {
final List<RouteSegment> segments;
RouteDefinition(this.segments);
Parser<RouteResult>? compile() {
Parser<RouteResult>? out;
for (var i = 0; i < segments.length; i++) {
var s = segments[i];
var isLast = i == segments.length - 1;
if (out == null) {
out = s.compile(isLast);
} else {
out = s.compileNext(
out.then(match('/')).index(0).cast<RouteResult>(), isLast);
}
}
return out;
}
}
abstract class RouteSegment {
Parser<RouteResult> compile(bool isLast);
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast);
}
class SlashSegment implements RouteSegment {
static final RegExp rgx = RegExp(r'/+');
const SlashSegment();
@override
Parser<RouteResult> compile(bool isLast) {
return match(rgx).map((_) => RouteResult({}));
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(compile(isLast)).index(0).cast<RouteResult>();
}
@override
String toString() => 'Slash';
}
class ConstantSegment extends RouteSegment {
final String? text;
ConstantSegment(this.text);
@override
String toString() {
return 'Constant: $text';
}
@override
Parser<RouteResult> compile(bool isLast) {
return match(text!).map((r) => RouteResult({}));
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(compile(isLast)).index(0).cast<RouteResult>();
}
}
class WildcardSegment extends RouteSegment {
final String pre, post;
WildcardSegment(this.pre, this.post);
@override
String toString() {
return 'Wildcard segment';
}
String _symbol(bool isLast) {
if (isLast) return r'.*';
return r'[^/]*';
}
RegExp _compile(bool isLast) {
return RegExp('$pre(${_symbol(isLast)})$post');
// if (isLast) return match(RegExp(r'.*'));
// return match(RegExp(r'[^/]*'));
}
@override
Parser<RouteResult> compile(bool isLast) {
return match(_compile(isLast)).map((r) {
var result = r.scanner.lastMatch;
if (result != null) {
//return RouteResult({}, tail: r.scanner.lastMatch![1])
return RouteResult({}, tail: result[1]);
} else {
return RouteResult({});
}
});
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(compile(isLast)).map((r) {
var items = r.value!.cast<RouteResult>();
var a = items[0], b = items[1];
return a
..addAll(b.params)
.._setTail(b.tail);
});
}
}
class OptionalSegment extends ParameterSegment {
final ParameterSegment parameter;
OptionalSegment(this.parameter) : super(parameter.name, parameter.regExp);
@override
String toString() {
return 'Optional: $parameter';
}
@override
Parser<RouteResult> compile(bool isLast) {
return super.compile(isLast).opt();
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(_compile().opt()).map((r) {
// Return an empty RouteResult if null
if (r.value == null) {
return RouteResult({});
}
var v = r.value!;
if (v[1] == null) {
return v[0] as RouteResult;
}
return (v[0] as RouteResult)
..addAll({name: Uri.decodeComponent(v as String)});
});
}
}
class ParameterSegment extends RouteSegment {
final String name;
final RegExp? regExp;
ParameterSegment(this.name, this.regExp);
@override
String toString() {
if (regExp != null) {
return 'Param: $name (${regExp?.pattern})';
}
return 'Param: $name';
}
Parser<String> _compile() {
if (regExp != null) {
return match<String>(regExp!).value((r) {
var result = r.scanner.lastMatch;
if (result != null) {
// TODO: Invalid method
//return r.scanner.lastMatch![1];
return result.toString();
} else {
return '';
}
});
} else {
return RouteGrammar.notSlash;
}
}
@override
Parser<RouteResult> compile(bool isLast) {
return _compile()
.map((r) => RouteResult({name: Uri.decodeComponent(r.value!)}));
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(_compile()).map((r) {
return (r.value![0] as RouteResult)
..addAll({name: Uri.decodeComponent(r.value![1] as String)});
});
}
}
class ParsedParameterSegment extends RouteSegment {
final String type;
final ParameterSegment parameter;
ParsedParameterSegment(this.type, this.parameter);
num getValue(String s) {
switch (type) {
case 'int':
return int.parse(s);
case 'double':
return double.parse(s);
default:
return num.parse(s);
}
}
@override
Parser<RouteResult> compile(bool isLast) {
return parameter._compile().map((r) => RouteResult(
{parameter.name: getValue(Uri.decodeComponent(r.span!.text))}));
}
@override
Parser<RouteResult> compileNext(Parser<RouteResult> p, bool isLast) {
return p.then(parameter._compile()).map((r) {
return (r.value![0] as RouteResult)
..addAll({
parameter.name: getValue(Uri.decodeComponent(r.value![1] as String))
});
});
}
}