Add C support

README.md

@@ -77,6 +77,9 @@ The following are languages which have built-in support in genco.
 * [🌐 <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**
@@ -136,6 +139,8 @@ fn main() {
 [dart-example]: https://github.com/udoprog/genco/blob/master/examples/dart.rs
 [js]: https://docs.rs/genco/latest/genco/lang/js/index.html
 [js-example]: https://github.com/udoprog/genco/blob/master/examples/js.rs
+[c]: https://docs.rs/genco/latest/genco/lang/c/index.html
+[c-example]: https://github.com/udoprog/genco/blob/master/examples/c.rs
 [python]: https://docs.rs/genco/latest/genco/lang/python/index.html
 [python-example]: https://github.com/udoprog/genco/blob/master/examples/python.rs
 [solve namespace conflicts]: https://docs.rs/genco/latest/genco/lang/csharp/fn.import.html

examples/c.rs

@@ -0,0 +1,30 @@
+use genco::fmt;
+use genco::prelude::*;
+
+fn main() -> anyhow::Result<()> {
+    let printf = &c::include_system("stdio.h", "printf");
+
+    let day = "tuesday";
+    let name = "George";
+
+    let tokens = quote! {
+        const char* greet_user() {
+            return $(quoted(format!("Hello {}!", name)));
+        }
+
+        int main() {
+            const char* current_day = $(quoted(day));
+            $printf("%s\n", current_day);
+            $printf("%s\n", greet_user());
+        }
+    };
+
+    let stdout = std::io::stdout();
+    let mut w = fmt::IoWriter::new(stdout.lock());
+
+    let fmt = fmt::Config::from_lang::<C>();
+    let config = c::Config::default().with_package("main");
+
+    tokens.format_file(&mut w.as_formatter(&fmt), &config)?;
+    Ok(())
+}

src/lang/c.rs

@@ -0,0 +1,178 @@
+//! Specialization for C code generation.
+
+use crate as genco;
+use crate::fmt;
+use crate::quote_in;
+use crate::tokens::{quoted, ItemStr};
+use std::collections::BTreeSet;
+use std::fmt::Write as _;
+
+/// Tokens container specialization for C.
+pub type Tokens = crate::Tokens<C>;
+
+impl_lang! {
+    /// Language specialization for C.
+    pub C {
+        type Config = Config;
+        type Format = Format;
+        type Item = Import;
+
+        fn write_quoted(out: &mut fmt::Formatter<'_>, input: &str) -> fmt::Result {
+            super::c_family_write_quoted(out, input)
+        }
+
+        fn format_file(
+            tokens: &Tokens,
+            out: &mut fmt::Formatter<'_>,
+            config: &Self::Config,
+        ) -> fmt::Result {
+            let mut header = Tokens::new();
+
+            if let Some(package) = &config.package {
+                quote_in!(header => package $package);
+                header.line();
+            }
+
+            Self::imports(&mut header, tokens);
+            let format = Format::default();
+            header.format(out, config, &format)?;
+            tokens.format(out, config, &format)?;
+            Ok(())
+        }
+    }
+
+    Import {
+        fn format(&self, out: &mut fmt::Formatter<'_>, _: &Config, _: &Format) -> fmt::Result {
+            out.write_str(&self.item)?;
+            Ok(())
+        }
+    }
+}
+
+/// The include statement for a C header file such as `#include "foo/bar.h"` or
+/// `#include <stdio.h>`.
+///
+/// Created using the [include()] function.
+#[derive(Debug, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
+pub struct Import {
+    /// Path to included file.
+    path: ItemStr,
+    /// Item declared in the included file.
+    item: ItemStr,
+    /// True if the include is specified as a system header using `<>`, false if a local header using `""`.
+    system: bool,
+}
+
+/// Format for C.
+#[derive(Debug, Default)]
+pub struct Format {}
+
+/// Config data for C.
+#[derive(Debug, Default)]
+pub struct Config {
+    package: Option<ItemStr>,
+}
+
+impl Config {
+    /// Configure the specified package.
+    pub fn with_package<P: Into<ItemStr>>(self, package: P) -> Self {
+        Self {
+            package: Some(package.into()),
+        }
+    }
+}
+
+impl C {
+    fn imports(out: &mut Tokens, tokens: &Tokens) {
+        let mut includes = BTreeSet::new();
+
+        for include in tokens.walk_imports() {
+            includes.insert((&include.path, include.system));
+        }
+
+        if includes.is_empty() {
+            return;
+        }
+
+        for (file, system_header) in includes {
+            if system_header {
+                quote_in!(*out => #include <$(file)>);
+            } else {
+                quote_in!(*out => #include $(quoted(file)));
+            }
+            out.push();
+        }
+
+        out.line();
+    }
+}
+
+/// Include an item declared in a local C header file such as `#include "foo/bar.h"`
+///
+/// # Examples
+///
+/// ```
+/// use genco::prelude::*;
+///
+/// let fizzbuzz = c::include("foo/bar.h", "fizzbuzz");
+///
+/// let fizzbuzz_toks = quote! {
+///     $fizzbuzz
+/// };
+///
+/// assert_eq!(
+///     vec![
+///        "#include \"foo/bar.h\"",
+///        "",
+///        "fizzbuzz",
+///     ],
+///     fizzbuzz_toks.to_file_vec()?
+/// );
+/// # Ok::<_, genco::fmt::Error>(())
+/// ```
+pub fn include<M, N>(path: M, item: N) -> Import
+where
+    M: Into<ItemStr>,
+    N: Into<ItemStr>,
+{
+    Import {
+        path: path.into(),
+        item: item.into(),
+        system: false,
+    }
+}
+
+/// Include an item declared in a C system header such as `#include <stdio.h>`.
+///
+/// # Examples
+///
+/// ```
+/// use genco::prelude::*;
+///
+/// let printf = c::include_system("stdio.h", "printf");
+///
+/// let printf_toks = quote! {
+///     $printf
+/// };
+///
+/// assert_eq!(
+///     vec![
+///        "#include <stdio.h>",
+///        "",
+///        "printf",
+///     ],
+///     printf_toks.to_file_vec()?
+/// );
+/// # Ok::<_, genco::fmt::Error>(())
+/// ```
+pub fn include_system<M, N>(path: M, item: N) -> Import
+where
+    M: Into<ItemStr>,
+    N: Into<ItemStr>,
+{
+    Import {
+        path: path.into(),
+        item: item.into(),
+        system: true,
+    }
+}

src/lang/mod.rs

@@ -17,6 +17,7 @@
 //! # }
 //! ```
 
+pub mod c;
 pub mod csharp;
 pub mod dart;
 pub mod go;
@@ -26,6 +27,7 @@ pub mod python;
 pub mod rust;
 pub mod swift;
 
+pub use self::c::C;
 pub use self::csharp::Csharp;
 pub use self::dart::Dart;
 pub use self::go::Go;

src/lib.rs

@@ -74,6 +74,9 @@
 //! * [🌐 <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**
@@ -134,6 +137,8 @@
 //! [dart-example]: https://github.com/udoprog/genco/blob/master/examples/dart.rs
 //! [js]: https://docs.rs/genco/latest/genco/lang/js/index.html
 //! [js-example]: https://github.com/udoprog/genco/blob/master/examples/js.rs
+//! [c]: https://docs.rs/genco/latest/genco/lang/c/index.html
+//! [c-example]: https://github.com/udoprog/genco/blob/master/examples/c.rs
 //! [python]: https://docs.rs/genco/latest/genco/lang/python/index.html
 //! [python-example]: https://github.com/udoprog/genco/blob/master/examples/python.rs
 //! [solve namespace conflicts]: https://docs.rs/genco/latest/genco/lang/csharp/fn.import.html