Match.named

Declaration and parameters

Доступность

Включено по умолчанию · Не определено

Import std.regex in language mode 5.21.

The current compiler selects std/regex.tpz for this language mode. Availability in other released editions and inclusion in each installed distribution are Pending.

Получатель

Match

Ограничения параметров

Дополнительные контракты не определены.

Match.start and Match.end are read-only nonnegative UTF-8 byte offsets in the original input. They follow the inclusive start and exclusive end of byte intervals. Both are scalar boundaries and the end does not exceed the UTF-8 byte length of the input.

Match.text is the matched substring. An empty match has equal start and end and an empty text value. The offsets are not string grapheme indexes. A match may select a combining mark inside a grapheme.

Encoding the original input with encodeUtf8, slicing its bytes from start to end, and calling decodeUtf8 returns Ok containing Match.text. This relationship also holds for non-ASCII input.

Match.groups returns an independent array indexed by capture number. Entry zero is Some containing the entire match. Capturing parentheses are numbered from one in opening-parenthesis order. Named groups participate in the same numbering and noncapturing groups do not.

A nonparticipating capture has value None(). A participating empty capture has value Some containing an empty string. A repeated capture retains the last participating capture in the selected match.

Match.named returns an independent map from capture names to captured strings. A nonparticipating named capture is absent. A participating empty named capture is present with an empty string. Names are inserted in ascending ASCII order.

Reading a Match field evaluates its receiver once and does not modify the Match or input. Mutating a groups array or named map does not affect a later field read. Field access cannot fail for a Match value.

Связанное правило · Read match boundaries and capture snapshots →

Результат

Дополнительные контракты не определены.

The declared result type is Map<string, string>.

Эффекты

Не определено

Ошибки

Не определено

Result and effects

Ссылка

Select this field from a value of its named type without call parentheses.

An independent map of participating named captures, including captured empty strings.

Resolved contracts

Ссылка

std.regex →

Read match boundaries and capture snapshots

Ссылка

Правилоtopaz.stdlib.contract.regex-match.rule

Read match boundaries and capture snapshots

Match.start and Match.end are read-only nonnegative UTF-8 byte offsets in the original input. They follow the inclusive start and exclusive end of byte intervals. Both are scalar boundaries and the end does not exceed the UTF-8 byte length of the input.

Match.text is the matched substring. An empty match has equal start and end and an empty text value. The offsets are not string grapheme indexes. A match may select a combining mark inside a grapheme.

Encoding the original input with encodeUtf8, slicing its bytes from start to end, and calling decodeUtf8 returns Ok containing Match.text. This relationship also holds for non-ASCII input.

Match.groups returns an independent array indexed by capture number. Entry zero is Some containing the entire match. Capturing parentheses are numbered from one in opening-parenthesis order. Named groups participate in the same numbering and noncapturing groups do not.

A nonparticipating capture has value None(). A participating empty capture has value Some containing an empty string. A repeated capture retains the last participating capture in the selected match.

Match.named returns an independent map from capture names to captured strings. A nonparticipating named capture is absent. A participating empty named capture is present with an empty string. Names are inserted in ascending ASCII order.

Reading a Match field evaluates its receiver once and does not modify the Match or input. Mutating a groups array or named map does not affect a later field read. Field access cannot fail for a Match value.

Причина

Byte offsets identify every exact match even when a pattern selects part of a grapheme. The byte-slice relationship makes those offsets usable without confusing them with text indexing. Optional numbered captures and omitted named entries distinguish absence from a captured empty string.

Примеры Report UTF-8 byte offsets for non-ASCII matches →Recover a match through the byte slice identified by its offsets →Keep capture zero and distinguish missing and empty captures →Omit absent named captures and retain a captured empty string →

Report UTF-8 byte offsets for non-ASCII matches

Ссылка

run · running · Проверка · Не выполнялось

main.tpzReport UTF-8 byte offsets for non-ASCII matchesОткрыть песочницу →

import std.regex { Regex }
import std.io
function show(patternText: string, text: string) -> () {
match (Regex.compile(patternText)) {
case Ok(pattern) => {
match (pattern.find(text)) {
case Some(found) => io.writeLine("{found.start}:{found.end}:{found.text}")
case None() => io.writeLine("no match")
}
}
case Err(_) => io.writeLine("compile failed")
}
}
show("한", "é한🙂")
show("́", "éx")

Ожидаемый выводКод завершения 0

2:5:한
1:3:́

$ topaz run main.tpz · Целевой продукт 5.21.3

Ожидаемый результат

Выполнение завершается. Код завершения 0.

Нет вывода ошибок.

Ожидаемый стандартный вывод

2:5:한
1:3:́

Этот пример ещё не выполнялся.

Recover a match through the byte slice identified by its offsets

Ссылка

run · running · Проверка · Не выполнялось

main.tpzRecover a match through the byte slice identified by its offsetsОткрыть песочницу →

import std.regex { Regex }
import std.io
let text = "한x"
match (Regex.compile("한")) {
case Ok(pattern) => {
match (pattern.find(text)) {
case Some(found) => {
let bytes = text.encodeUtf8().slice(found.start, found.end)
match (bytes.decodeUtf8()) {
case Ok(decoded) => io.writeLine(decoded)
case Err(_) => io.writeLine("invalid UTF-8 slice")
}
}
case None() => io.writeLine("no match")
}
}
case Err(_) => io.writeLine("compile failed")
}

Ожидаемый выводКод завершения 0

한

$ topaz run main.tpz · Целевой продукт 5.21.3

Ожидаемый результат

Выполнение завершается. Код завершения 0.

Нет вывода ошибок.

Ожидаемый стандартный вывод

한

Этот пример ещё не выполнялся.

Keep capture zero and distinguish missing and empty captures

Ссылка

run · running · Проверка · Не выполнялось

main.tpzKeep capture zero and distinguish missing and empty capturesОткрыть песочницу →

import std.regex { Regex }
import std.io
match (Regex.compile("(?<word>a)(b)?()")) {
case Ok(pattern) => {
match (pattern.find("a")) {
case Some(found) => {
io.writeLine("{found.groups.length}")
for group in (found.groups) {
match (group) {
case Some(text) => io.writeLine("some={text}")
case None() => io.writeLine("none")
}
}
}
case None() => io.writeLine("no match")
}
}
case Err(_) => io.writeLine("compile failed")
}

Ожидаемый выводКод завершения 0

4
some=a
some=a
none
some=

$ topaz run main.tpz · Целевой продукт 5.21.3

Ожидаемый результат

Выполнение завершается. Код завершения 0.

Нет вывода ошибок.

Ожидаемый стандартный вывод

4
some=a
some=a
none
some=

Этот пример ещё не выполнялся.

Omit absent named captures and retain a captured empty string

Ссылка

run · running · Проверка · Не выполнялось

main.tpzOmit absent named captures and retain a captured empty stringОткрыть песочницу →

import std.regex { Regex }
import std.io
match (Regex.compile("(?<z>a)?(?<a>b*)")) {
case Ok(pattern) => {
match (pattern.find("")) {
case Some(found) => {
let mut snapshot = found.named
let hasOptional = snapshot.containsKey("z")
io.writeLine("{hasOptional}")
match (snapshot.get("a")) {
case Some(text) => io.writeLine("some={text}")
case None() => io.writeLine("none")
}
snapshot.insert("a", "changed")
match (found.named.get("a")) {
case Some(text) => io.writeLine("again={text}")
case None() => io.writeLine("none")
}
}
case None() => io.writeLine("no match")
}
}
case Err(_) => io.writeLine("compile failed")
}

Ожидаемый выводКод завершения 0

false
some=
again=

$ topaz run main.tpz · Целевой продукт 5.21.3

Ожидаемый результат

Выполнение завершается. Код завершения 0.

Нет вывода ошибок.

Ожидаемый стандартный вывод

false
some=
again=

Этот пример ещё не выполнялся.

Поиск в документации

Declaration and parameters

Доступность

Получатель

Ограничения параметров

Результат

Эффекты

Ошибки

Result and effects

Resolved contracts

Read match boundaries and capture snapshots

Read match boundaries and capture snapshots

Причина

Report UTF-8 byte offsets for non-ASCII matches

Ожидаемый результат

Recover a match through the byte slice identified by its offsets

Ожидаемый результат

Keep capture zero and distinguish missing and empty captures

Ожидаемый результат

Omit absent named captures and retain a captured empty string

Ожидаемый результат

Меню

Declaration and parameters

Доступность

Получатель

Ограничения параметров

Результат

Эффекты

Ошибки

Result and effects

Resolved contracts

Related entries

Read match boundaries and capture snapshots

Read match boundaries and capture snapshots

Причина

Report UTF-8 byte offsets for non-ASCII matches

Ожидаемый результат

Recover a match through the byte slice identified by its offsets

Ожидаемый результат

Keep capture zero and distinguish missing and empty captures

Ожидаемый результат

Omit absent named captures and retain a captured empty string

Ожидаемый результат