genco 0.17.10

A whitespace-aware quasiquoter for beautiful code generation.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

# genco

[<img alt="github" src="https://img.shields.io/badge/github-udoprog/genco-8da0cb?style=for-the-badge&logo=github" height="20">](https://github.com/udoprog/genco)
[<img alt="crates.io" src="https://img.shields.io/crates/v/genco.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/genco)
[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-genco-66c2a5?style=for-the-badge&logoColor=white&logo=data:image/svg+xml;base64,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" height="20">](https://docs.rs/genco)
[<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/udoprog/genco/ci.yml?branch=main&style=for-the-badge" height="20">](https://github.com/udoprog/genco/actions?query=branch%3Amain)

A whitespace-aware quasiquoter for beautiful code generation.

Central to genco are the [quote!] and [quote_in!] procedural macros which
ease the construction of [token streams].

This project solves the following language-specific concerns:

* **Imports** — Generates and groups [import statements] as they are used.
  So you only import what you use, with no redundancy. We also do our best
  to [solve namespace conflicts].

* **String Quoting** — genco knows how to [quote strings]. And can even
  [interpolate] values *into* the quoted string if it's supported by the
  language.

* **Structural Indentation** — The quoter relies on intuitive
  [whitespace detection] to structurally sort out spacings and indentation.
  Allowing genco to generate beautiful readable code with minimal effort.
  This is also a requirement for generating correctly behaving code in
  languages like Python where [indentation is meaningful].

* **Language Customization** — Building support for new languages is a
  piece of cake with the help of the [impl_lang!] macro.

<br>

To support line changes during [whitespace detection], we depend on the
nightly [`proc_macro_span` feature]. On stable we can only detect column
changes.

*Until this is stabilized* and you want fully functional whitespace
detection you must build and run projects using genco with a `nightly`
compiler. This is important for whitespace-sensitive languages like python.

You can try the difference between:

```bash
cargo run --example rust
```

And:

```bash
cargo +nightly run --example rust
```

[`proc_macro_span` feature]: https://github.com/rust-lang/rust/issues/54725

<br>

## Supported Languages

The following are languages which have built-in support in genco.

* [🦀 <b>Rust</b>][rust]<br>
  <small>[Example][rust-example]</small>

* [☕ <b>Java</b>][java]<br>
  <small>[Example][java-example]</small>

* [🎼 <b>C#</b>][c#]<br>
  <small>[Example][c#-example]</small>

* [🐿️ <b>Go</b>][go]<br>
  <small>[Example][go-example]</small>

* [🎯 <b>Dart</b>][dart]<br>
  <small>[Example][dart-example]</small>

* [🌐 <b>JavaScript</b>][js]<br>
  <small>[Example][js-example]</small>

* [🇨 <b>C</b>][c]<br>
  <small>[Example][c-example]</small>

* [🐍 <b>Python</b>][python]<br>
  <small>[Example][python-example]</small><br>
  **Requires a `nightly` compiler**

<small>Is your favorite language missing? <b>[Open an issue!]</b></small>

You can run one of the examples by:

```bash
cargo +nightly run --example rust
```

<br>

## Rust Example

The following is a simple program producing Rust code to stdout with custom
configuration:

```rust
use genco::prelude::*;

let hash_map = rust::import("std::collections", "HashMap");

let tokens: rust::Tokens = quote! {
    fn main() {
        let mut m = $hash_map::new();
        m.insert(1u32, 2u32);
    }
};

println!("{}", tokens.to_file_string()?);
```

This would produce:

```rust,no_test
use std::collections::HashMap;

fn main() {
    let mut m = HashMap::new();
    m.insert(1u32, 2u32);
}
```

<br>

[c-example]: https://github.com/udoprog/genco/blob/master/examples/c.rs
[c]: https://docs.rs/genco/latest/genco/lang/c/index.html
[c#-example]: https://github.com/udoprog/genco/blob/master/examples/csharp.rs
[c#]: https://docs.rs/genco/latest/genco/lang/csharp/index.html
[dart-example]: https://github.com/udoprog/genco/blob/master/examples/dart.rs
[dart]: https://docs.rs/genco/latest/genco/lang/dart/index.html
[go-example]: https://github.com/udoprog/genco/blob/master/examples/go.rs
[go]: https://docs.rs/genco/latest/genco/lang/go/index.html
[impl_lang!]: https://docs.rs/genco/latest/genco/macro.impl_lang.html
[import statements]: https://docs.rs/genco/latest/genco/macro.quote.html#imports
[indentation is meaningful]: https://docs.python.org/3/faq/design.html#why-does-python-use-indentation-for-grouping-of-statements
[interpolate]: https://docs.rs/genco/latest/genco/macro.quote.html#quoted-string-interpolation
[java-example]: https://github.com/udoprog/genco/blob/master/examples/java.rs
[java]: https://docs.rs/genco/latest/genco/lang/java/index.html
[js-example]: https://github.com/udoprog/genco/blob/master/examples/js.rs
[js]: https://docs.rs/genco/latest/genco/lang/js/index.html
[Open an issue!]: https://github.com/udoprog/genco/issues/new
[python-example]: https://github.com/udoprog/genco/blob/master/examples/python.rs
[python]: https://docs.rs/genco/latest/genco/lang/python/index.html
[quote strings]: https://docs.rs/genco/latest/genco/macro.quote.html#string-quoting
[quote_in!]: https://docs.rs/genco/latest/genco/macro.quote_in.html
[quote!]: https://docs.rs/genco/latest/genco/macro.quote.html
[quoted()]: https://docs.rs/genco/latest/genco/tokens/fn.quoted.html
[rust-example]: https://github.com/udoprog/genco/blob/master/examples/rust.rs
[rust]: https://docs.rs/genco/latest/genco/lang/rust/index.html
[solve namespace conflicts]: https://docs.rs/genco/latest/genco/lang/csharp/fn.import.html
[token streams]: https://docs.rs/genco/latest/genco/tokens/struct.Tokens.html
[whitespace detection]: https://docs.rs/genco/latest/genco/macro.quote.html#whitespace-detection