https://github.com/sile/textparse

A Rust library to declaratively implement parsers that are based on Packrat Parsing.
https://github.com/sile/textparse

parser rust

Last synced: about 1 year ago
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A Rust library to declaratively implement parsers that are based on Packrat Parsing.

• Host: GitHub
• URL: https://github.com/sile/textparse
• Owner: sile
• License: apache-2.0
• Created: 2022-11-06T03:46:14.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2022-12-25T04:21:15.000Z (over 3 years ago)
• Last Synced: 2024-05-01T23:47:30.744Z (about 2 years ago)
• Topics: parser, rust
• Language: Rust
• Homepage:
• Size: 119 KB
• Stars: 2
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE

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README

          
textparse

=========

[![textparse](https://img.shields.io/crates/v/textparse.svg)](https://crates.io/crates/textparse)

[![Documentation](https://docs.rs/textparse/badge.svg)](https://docs.rs/textparse)

[![Actions Status](https://github.com/sile/textparse/workflows/CI/badge.svg)](https://github.com/sile/textparse/actions)

![License](https://img.shields.io/crates/l/textparse)

A Rust library to declaratively implement parsers that are based on Packrat Parsing.

Examples

--------

The following code implements a parser for a JSON subset format:

```rust

use textparse::{

    components::{AnyChar, Char, Digit, Eos, Items, NonEmpty, Not, Str, While, Whitespace},

    Parse, Parser, Position, Span,

};

#[derive(Clone, Span, Parse)]

struct JsonValue(WithoutWhitespaces);

#[derive(Clone, Span, Parse)]

#[parse(name = "a JSON value")]

enum JsonValueInner {

    Null(JsonNull),

    String(JsonString),

    Number(JsonNumber),

    Array(JsonArray),

    Object(JsonObject),

}

#[derive(Clone, Span, Parse)]

struct JsonNull(Str<'n', 'u', 'l', 'l'>);

#[derive(Clone, Span, Parse)]

#[parse(name = "a JSON string")]

struct JsonString(Char<'"'>, While<(Not>, AnyChar)>, Char<'"'>);

#[derive(Clone, Span, Parse)]

#[parse(name = "a JSON number")]

struct JsonNumber(NonEmpty>);

#[derive(Clone, Span, Parse)]

#[parse(name = "a JSON array")]

struct JsonArray(Char<'['>, Csv, Char<']'>);

#[derive(Clone, Span, Parse)]

#[parse(name = "a JSON object")]

struct JsonObject(Char<'{'>, Csv, Char<'}'>);

#[derive(Clone, Span, Parse)]

struct JsonObjectItem(WithoutWhitespaces, Char<':'>, JsonValue);

#[derive(Clone, Span, Parse)]

struct Csv(Items>);

#[derive(Clone, Span, Parse)]

struct WithoutWhitespaces(While, T, While);

```

You can run the above parser via [examples/check_json.rs](examples/check_json.rs) as follows:

```console

$ echo '["foo",null,{"key": "value"}, 123]' | cargo run --example check_json

OK: the input string is a JSON text.

$ echo '["foo" null]' | cargo run --example check_json

Error: expected one of ',', or ']'

  --> :1:8

  |

1 | ["foo" null]

  |        ^ expected one of ',', or ']'

```