Match. text: string- 수신자
- Match
- 최소 인자 수
- 0
- 최대 인자 수
- 0
Declaration and parameters
링크사용 조건
기본 포함 · 미정
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.
수신자
Match
매개변수 제약
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.
관련 규칙 · Read match boundaries and capture snapshots →결과
The declared result type is string.
효과
실패
Result and effects
링크Select this field from a value of its named type without call parentheses.
The complete matched substring, including an empty string for an empty match.
Resolved contracts
링크Related entries
링크Read match boundaries and capture snapshots
링크Read 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.
이유
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.
Report UTF-8 byte offsets for non-ASCII matches
링크import std.regex { Regex }import std.iofunction 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")
2:5:한
1:3:́
기대 결과
기대 결과
실행을 마칩니다. 종료 코드 0.
2:5:한1:3:́
Recover a match through the byte slice identified by its offsets
링크import std.regex { Regex }import std.iolet 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")}
한
기대 결과
기대 결과
실행을 마칩니다. 종료 코드 0.
한
Keep capture zero and distinguish missing and empty captures
링크import std.regex { Regex }import std.iomatch (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")}
4
some=a
some=a
none
some=
기대 결과
기대 결과
실행을 마칩니다. 종료 코드 0.
4some=asome=anonesome=
Omit absent named captures and retain a captured empty string
링크import std.regex { Regex }import std.iomatch (Regex.compile("(?<z>a)?(?<a>b*)")) {case Ok(pattern) => {match (pattern.find("")) {case Some(found) => {let mut snapshot = found.namedlet 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")}
false
some=
again=
기대 결과
기대 결과
실행을 마칩니다. 종료 코드 0.
falsesome=again=