mirror of
https://github.com/quickwit-oss/tantivy.git
synced 2026-05-23 11:40:40 +00:00
90 lines
9.2 KiB
HTML
90 lines
9.2 KiB
HTML
<!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="API documentation for the Rust `value` mod in crate `serde_json`."><meta name="keywords" content="rust, rustlang, rust-lang, value"><title>serde_json::value - Rust</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script src="../../storage.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="shortcut icon" href="../../favicon.ico"><style type="text/css">#crate-search{background-image:url("../../down-arrow.svg");}</style></head><body class="rustdoc mod"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../serde_json/index.html'><img src='../../rust-logo.png' alt='logo' width='100'></a><p class='location'>Module value</p><div class="sidebar-elems"><div class="block items"><ul><li><a href="#reexports">Re-exports</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#traits">Traits</a></li><li><a href="#functions">Functions</a></li></ul></div><p class='location'><a href='../index.html'>serde_json</a></p><script>window.sidebarCurrent = {name: 'value', ty: 'mod', relpath: '../'};</script><script defer src="../sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../../settings.html"><img src="../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>−</span>]</a></span><a class='srclink' href='../../src/serde_json/value/mod.rs.html#1-1011' title='goto source code'>[src]</a></span><span class='in-band'>Module <a href='../index.html'>serde_json</a>::<wbr><a class="mod" href=''>value</a></span></h1><div class='docblock'><p>The Value enum, a loosely typed way of representing any valid JSON value.</p>
|
||
<h1 id="constructing-json" class="section-header"><a href="#constructing-json">Constructing JSON</a></h1>
|
||
<p>Serde JSON provides a <a href="https://docs.serde.rs/serde_json/macro.json.html"><code>json!</code> macro</a> to build <code>serde_json::Value</code>
|
||
objects with very natural JSON syntax. In order to use this macro,
|
||
<code>serde_json</code> needs to be imported with the <code>#[macro_use]</code> attribute.</p>
|
||
<pre><code class="language-edition2018">use serde_json::json;
|
||
|
||
fn main() {
|
||
// The type of `john` is `serde_json::Value`
|
||
let john = json!({
|
||
"name": "John Doe",
|
||
"age": 43,
|
||
"phones": [
|
||
"+44 1234567",
|
||
"+44 2345678"
|
||
]
|
||
});
|
||
|
||
println!("first phone number: {}", john["phones"][0]);
|
||
|
||
// Convert to a string of JSON and print it out
|
||
println!("{}", john.to_string());
|
||
}
|
||
</code></pre>
|
||
<p>The <code>Value::to_string()</code> function converts a <code>serde_json::Value</code> into a
|
||
<code>String</code> of JSON text.</p>
|
||
<p>One neat thing about the <code>json!</code> macro is that variables and expressions can
|
||
be interpolated directly into the JSON value as you are building it. Serde
|
||
will check at compile time that the value you are interpolating is able to
|
||
be represented as JSON.</p>
|
||
<pre><code class="language-edition2018"># use serde_json::json;
|
||
#
|
||
# fn random_phone() -> u16 { 0 }
|
||
#
|
||
let full_name = "John Doe";
|
||
let age_last_year = 42;
|
||
|
||
// The type of `john` is `serde_json::Value`
|
||
let john = json!({
|
||
"name": full_name,
|
||
"age": age_last_year + 1,
|
||
"phones": [
|
||
format!("+44 {}", random_phone())
|
||
]
|
||
});
|
||
</code></pre>
|
||
<p>A string of JSON data can be parsed into a <code>serde_json::Value</code> by the
|
||
<a href="https://docs.serde.rs/serde_json/de/fn.from_str.html"><code>serde_json::from_str</code></a> function. There is also
|
||
<a href="https://docs.serde.rs/serde_json/de/fn.from_slice.html"><code>from_slice</code></a> for parsing from a byte slice <code>&[u8]</code> and
|
||
<a href="https://docs.serde.rs/serde_json/de/fn.from_reader.html"><code>from_reader</code></a> for parsing from any <code>io::Read</code> like a File or
|
||
a TCP stream.</p>
|
||
<pre><code class="language-edition2018">use serde_json::{json, Value, Error};
|
||
|
||
fn untyped_example() -> Result<(), Error> {
|
||
// Some JSON input data as a &str. Maybe this comes from the user.
|
||
let data = r#"
|
||
{
|
||
"name": "John Doe",
|
||
"age": 43,
|
||
"phones": [
|
||
"+44 1234567",
|
||
"+44 2345678"
|
||
]
|
||
}"#;
|
||
|
||
// Parse the string of data into serde_json::Value.
|
||
let v: Value = serde_json::from_str(data)?;
|
||
|
||
// Access parts of the data by indexing with square brackets.
|
||
println!("Please call {} at the number {}", v["name"], v["phones"][0]);
|
||
|
||
Ok(())
|
||
}
|
||
#
|
||
# fn main() {
|
||
# untyped_example().unwrap();
|
||
# }
|
||
</code></pre>
|
||
</div><h2 id='reexports' class='section-header'><a href="#reexports">Re-exports</a></h2>
|
||
<table><tr><td><code>pub use map::<a class="struct" href="../../serde_json/map/struct.Map.html" title="struct serde_json::map::Map">Map</a>;</code></td></tr></table><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
|
||
<table><tr class='module-item'><td><a class="struct" href="struct.Number.html" title='serde_json::value::Number struct'>Number</a></td><td class='docblock-short'><p>Represents a JSON number, whether integer or floating point.</p>
|
||
</td></tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
|
||
<table><tr class='module-item'><td><a class="enum" href="enum.Value.html" title='serde_json::value::Value enum'>Value</a></td><td class='docblock-short'><p>Represents any valid JSON value.</p>
|
||
</td></tr></table><h2 id='traits' class='section-header'><a href="#traits">Traits</a></h2>
|
||
<table><tr class='module-item'><td><a class="trait" href="trait.Index.html" title='serde_json::value::Index trait'>Index</a></td><td class='docblock-short'><p>A type that can be used to index into a <code>serde_json::Value</code>.</p>
|
||
</td></tr></table><h2 id='functions' class='section-header'><a href="#functions">Functions</a></h2>
|
||
<table><tr class='module-item'><td><a class="fn" href="fn.from_value.html" title='serde_json::value::from_value fn'>from_value</a></td><td class='docblock-short'><p>Interpret a <code>serde_json::Value</code> as an instance of type <code>T</code>.</p>
|
||
</td></tr><tr class='module-item'><td><a class="fn" href="fn.to_value.html" title='serde_json::value::to_value fn'>to_value</a></td><td class='docblock-short'><p>Convert a <code>T</code> into <code>serde_json::Value</code> which is an enum that can represent
|
||
any valid JSON data.</p>
|
||
</td></tr></table></section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../../";window.currentCrate = "serde_json";</script><script src="../../aliases.js"></script><script src="../../main.js"></script><script defer src="../../search-index.js"></script></body></html> |