| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/regex-syntax-0.7.2/src/parser.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>parser.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../regex_syntax/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../regex_syntax/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use crate</span>::{ast, hir, Error}; |
| |
| <span class="doccomment">/// A convenience routine for parsing a regex using default options. |
| /// |
| /// This is equivalent to `Parser::new().parse(pattern)`. |
| /// |
| /// If you need to set non-default options, then use a [`ParserBuilder`]. |
| /// |
| /// This routine returns an [`Hir`](hir::Hir) value. Namely, it automatically |
| /// parses the pattern as an [`Ast`](ast::Ast) and then invokes the translator |
| /// to convert the `Ast` into an `Hir`. If you need access to the `Ast`, then |
| /// you should use a [`ast::parse::Parser`]. |
| </span><span class="kw">pub fn </span>parse(pattern: <span class="kw-2">&</span>str) -> <span class="prelude-ty">Result</span><hir::Hir, Error> { |
| Parser::new().parse(pattern) |
| } |
| |
| <span class="doccomment">/// A builder for a regular expression parser. |
| /// |
| /// This builder permits modifying configuration options for the parser. |
| /// |
| /// This type combines the builder options for both the [AST |
| /// `ParserBuilder`](ast::parse::ParserBuilder) and the [HIR |
| /// `TranslatorBuilder`](hir::translate::TranslatorBuilder). |
| </span><span class="attribute">#[derive(Clone, Debug, Default)] |
| </span><span class="kw">pub struct </span>ParserBuilder { |
| ast: ast::parse::ParserBuilder, |
| hir: hir::translate::TranslatorBuilder, |
| } |
| |
| <span class="kw">impl </span>ParserBuilder { |
| <span class="doccomment">/// Create a new parser builder with a default configuration. |
| </span><span class="kw">pub fn </span>new() -> ParserBuilder { |
| ParserBuilder::default() |
| } |
| |
| <span class="doccomment">/// Build a parser from this configuration with the given pattern. |
| </span><span class="kw">pub fn </span>build(<span class="kw-2">&</span><span class="self">self</span>) -> Parser { |
| Parser { ast: <span class="self">self</span>.ast.build(), hir: <span class="self">self</span>.hir.build() } |
| } |
| |
| <span class="doccomment">/// Set the nesting limit for this parser. |
| /// |
| /// The nesting limit controls how deep the abstract syntax tree is allowed |
| /// to be. If the AST exceeds the given limit (e.g., with too many nested |
| /// groups), then an error is returned by the parser. |
| /// |
| /// The purpose of this limit is to act as a heuristic to prevent stack |
| /// overflow for consumers that do structural induction on an `Ast` using |
| /// explicit recursion. While this crate never does this (instead using |
| /// constant stack space and moving the call stack to the heap), other |
| /// crates may. |
| /// |
| /// This limit is not checked until the entire Ast is parsed. Therefore, |
| /// if callers want to put a limit on the amount of heap space used, then |
| /// they should impose a limit on the length, in bytes, of the concrete |
| /// pattern string. In particular, this is viable since this parser |
| /// implementation will limit itself to heap space proportional to the |
| /// length of the pattern string. |
| /// |
| /// Note that a nest limit of `0` will return a nest limit error for most |
| /// patterns but not all. For example, a nest limit of `0` permits `a` but |
| /// not `ab`, since `ab` requires a concatenation, which results in a nest |
| /// depth of `1`. In general, a nest limit is not something that manifests |
| /// in an obvious way in the concrete syntax, therefore, it should not be |
| /// used in a granular way. |
| </span><span class="kw">pub fn </span>nest_limit(<span class="kw-2">&mut </span><span class="self">self</span>, limit: u32) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.ast.nest_limit(limit); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Whether to support octal syntax or not. |
| /// |
| /// Octal syntax is a little-known way of uttering Unicode codepoints in |
| /// a regular expression. For example, `a`, `\x61`, `\u0061` and |
| /// `\141` are all equivalent regular expressions, where the last example |
| /// shows octal syntax. |
| /// |
| /// While supporting octal syntax isn't in and of itself a problem, it does |
| /// make good error messages harder. That is, in PCRE based regex engines, |
| /// syntax like `\0` invokes a backreference, which is explicitly |
| /// unsupported in Rust's regex engine. However, many users expect it to |
| /// be supported. Therefore, when octal support is disabled, the error |
| /// message will explicitly mention that backreferences aren't supported. |
| /// |
| /// Octal syntax is disabled by default. |
| </span><span class="kw">pub fn </span>octal(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.ast.octal(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// When disabled, translation will permit the construction of a regular |
| /// expression that may match invalid UTF-8. |
| /// |
| /// When enabled (the default), the translator is guaranteed to produce an |
| /// expression that, for non-empty matches, will only ever produce spans |
| /// that are entirely valid UTF-8 (otherwise, the translator will return an |
| /// error). |
| /// |
| /// Perhaps surprisingly, when UTF-8 is enabled, an empty regex or even |
| /// a negated ASCII word boundary (uttered as `(?-u:\B)` in the concrete |
| /// syntax) will be allowed even though they can produce matches that split |
| /// a UTF-8 encoded codepoint. This only applies to zero-width or "empty" |
| /// matches, and it is expected that the regex engine itself must handle |
| /// these cases if necessary (perhaps by suppressing any zero-width matches |
| /// that split a codepoint). |
| </span><span class="kw">pub fn </span>utf8(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.utf8(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable verbose mode in the regular expression. |
| /// |
| /// When enabled, verbose mode permits insignificant whitespace in many |
| /// places in the regular expression, as well as comments. Comments are |
| /// started using `#` and continue until the end of the line. |
| /// |
| /// By default, this is disabled. It may be selectively enabled in the |
| /// regular expression by using the `x` flag regardless of this setting. |
| </span><span class="kw">pub fn </span>ignore_whitespace(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.ast.ignore_whitespace(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the case insensitive flag by default. |
| /// |
| /// By default this is disabled. It may alternatively be selectively |
| /// enabled in the regular expression itself via the `i` flag. |
| </span><span class="kw">pub fn </span>case_insensitive(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.case_insensitive(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the multi-line matching flag by default. |
| /// |
| /// By default this is disabled. It may alternatively be selectively |
| /// enabled in the regular expression itself via the `m` flag. |
| </span><span class="kw">pub fn </span>multi_line(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.multi_line(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the "dot matches any character" flag by default. |
| /// |
| /// By default this is disabled. It may alternatively be selectively |
| /// enabled in the regular expression itself via the `s` flag. |
| </span><span class="kw">pub fn </span>dot_matches_new_line(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.dot_matches_new_line(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the CRLF mode flag by default. |
| /// |
| /// By default this is disabled. It may alternatively be selectively |
| /// enabled in the regular expression itself via the `R` flag. |
| /// |
| /// When CRLF mode is enabled, the following happens: |
| /// |
| /// * Unless `dot_matches_new_line` is enabled, `.` will match any character |
| /// except for `\r` and `\n`. |
| /// * When `multi_line` mode is enabled, `^` and `$` will treat `\r\n`, |
| /// `\r` and `\n` as line terminators. And in particular, neither will |
| /// match between a `\r` and a `\n`. |
| </span><span class="kw">pub fn </span>crlf(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.crlf(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the "swap greed" flag by default. |
| /// |
| /// By default this is disabled. It may alternatively be selectively |
| /// enabled in the regular expression itself via the `U` flag. |
| </span><span class="kw">pub fn </span>swap_greed(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.swap_greed(yes); |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Enable or disable the Unicode flag (`u`) by default. |
| /// |
| /// By default this is **enabled**. It may alternatively be selectively |
| /// disabled in the regular expression itself via the `u` flag. |
| /// |
| /// Note that unless `utf8` is disabled (it's enabled by default), a |
| /// regular expression will fail to parse if Unicode mode is disabled and a |
| /// sub-expression could possibly match invalid UTF-8. |
| </span><span class="kw">pub fn </span>unicode(<span class="kw-2">&mut </span><span class="self">self</span>, yes: bool) -> <span class="kw-2">&mut </span>ParserBuilder { |
| <span class="self">self</span>.hir.unicode(yes); |
| <span class="self">self |
| </span>} |
| } |
| |
| <span class="doccomment">/// A convenience parser for regular expressions. |
| /// |
| /// This parser takes as input a regular expression pattern string (the |
| /// "concrete syntax") and returns a high-level intermediate representation |
| /// (the HIR) suitable for most types of analysis. In particular, this parser |
| /// hides the intermediate state of producing an AST (the "abstract syntax"). |
| /// The AST is itself far more complex than the HIR, so this parser serves as a |
| /// convenience for never having to deal with it at all. |
| /// |
| /// If callers have more fine grained use cases that need an AST, then please |
| /// see the [`ast::parse`] module. |
| /// |
| /// A `Parser` can be configured in more detail via a [`ParserBuilder`]. |
| </span><span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub struct </span>Parser { |
| ast: ast::parse::Parser, |
| hir: hir::translate::Translator, |
| } |
| |
| <span class="kw">impl </span>Parser { |
| <span class="doccomment">/// Create a new parser with a default configuration. |
| /// |
| /// The parser can be run with `parse` method. The parse method returns |
| /// a high level intermediate representation of the given regular |
| /// expression. |
| /// |
| /// To set configuration options on the parser, use [`ParserBuilder`]. |
| </span><span class="kw">pub fn </span>new() -> Parser { |
| ParserBuilder::new().build() |
| } |
| |
| <span class="doccomment">/// Parse the regular expression into a high level intermediate |
| /// representation. |
| </span><span class="kw">pub fn </span>parse(<span class="kw-2">&mut </span><span class="self">self</span>, pattern: <span class="kw-2">&</span>str) -> <span class="prelude-ty">Result</span><hir::Hir, Error> { |
| <span class="kw">let </span>ast = <span class="self">self</span>.ast.parse(pattern)<span class="question-mark">?</span>; |
| <span class="kw">let </span>hir = <span class="self">self</span>.hir.translate(pattern, <span class="kw-2">&</span>ast)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(hir) |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="regex_syntax" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
