Add font-family parser.

src/aspect_ratio.rs

@@ -54,7 +54,7 @@ impl std::str::FromStr for AspectRatio {
         }
 
         let start = s.pos();
-        let align = s.consume_ident();
+        let align = s.consume_ascii_ident();
         let align = match align {
             "none" => Align::None,
             "xMinYMin" => Align::XMinYMin,
@@ -74,7 +74,7 @@ impl std::str::FromStr for AspectRatio {
         let mut slice = false;
         if !s.at_end() {
             let start = s.pos();
-            let v = s.consume_ident();
+            let v = s.consume_ascii_ident();
             match v {
                 "meet" => {}
                 "slice" => slice = true,

src/color.rs

@@ -164,7 +164,7 @@ impl<'a> Stream<'a> {
             }
         } else {
             // TODO: remove allocation
-            let name = self.consume_ident().to_ascii_lowercase();
+            let name = self.consume_ascii_ident().to_ascii_lowercase();
             if name == "rgb" || name == "rgba" {
                 self.consume_byte(b'(')?;
 

src/error.rs

@@ -1,5 +1,5 @@
 /// List of all errors.
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum Error {
     /// An input data ended earlier than expected.
     ///
@@ -18,6 +18,13 @@ pub enum Error {
     /// then we will get `InvalidNumber`, because at least some data is valid.
     InvalidValue,
 
+    /// An invalid ident.
+    ///
+    /// CSS idents have certain rules with regard to the characters they may contain.
+    /// For example, they may not start with a number. If an invalid ident is encountered,
+    /// this error will be returned.
+    InvalidIdent,
+
     /// An invalid/unexpected character.
     ///
     /// The first byte is an actual one, others - expected.
@@ -48,6 +55,9 @@ impl std::fmt::Display for Error {
             Error::InvalidValue => {
                 write!(f, "invalid value")
             }
+            Error::InvalidIdent => {
+                write!(f, "invalid ident")
+            }
             Error::InvalidChar(ref chars, pos) => {
                 // Vec<u8> -> Vec<String>
                 let list: Vec<String> = chars

src/filter_functions.rs

@@ -161,7 +161,7 @@ impl<'a> FilterValueListParser<'a> {
         let s = &mut self.stream;
 
         let start = s.pos();
-        let name = s.consume_ident();
+        let name = s.consume_ascii_ident();
         s.skip_spaces();
         s.consume_byte(b'(')?;
         s.skip_spaces();

src/font.rs

@@ -0,0 +1,171 @@
+use crate::stream::Stream;
+use crate::Error;
+use std::fmt::Display;
+
+/// Parses a list of font families and generic families from a string.
+pub fn parse_font_families(text: &str) -> Result<Vec<FontFamily>, Error> {
+    let mut s = Stream::from(text);
+    let font_families = s.parse_font_families()?;
+
+    s.skip_spaces();
+    if !s.at_end() {
+        return Err(Error::UnexpectedData(s.calc_char_pos()));
+    }
+
+    Ok(font_families)
+}
+
+/// A type of font family.
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub enum FontFamily {
+    /// A serif font.
+    Serif,
+    /// A sans-serif font.
+    SansSerif,
+    /// A cursive font.
+    Cursive,
+    /// A fantasy font.
+    Fantasy,
+    /// A monospace font.
+    Monospace,
+    /// A custom named font.
+    Named(String),
+}
+
+impl Display for FontFamily {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let str = match self {
+            FontFamily::Monospace => "monospace".to_string(),
+            FontFamily::Serif => "serif".to_string(),
+            FontFamily::SansSerif => "sans-serif".to_string(),
+            FontFamily::Cursive => "cursive".to_string(),
+            FontFamily::Fantasy => "fantasy".to_string(),
+            FontFamily::Named(s) => format!("\"{}\"", s),
+        };
+        write!(f, "{}", str)
+    }
+}
+
+impl<'a> Stream<'a> {
+    pub fn parse_font_families(&mut self) -> Result<Vec<FontFamily>, Error> {
+        let mut families = vec![];
+
+        while !self.at_end() {
+            self.skip_spaces();
+
+            let family = {
+                let ch = self.curr_byte()?;
+                if ch == b'\'' || ch == b'\"' {
+                    let res = self.parse_quoted_string()?;
+                    FontFamily::Named(res.to_string())
+                } else {
+                    let mut idents = vec![];
+
+                    while let Some(c) = self.chars().next() {
+                        if c != ',' {
+                            idents.push(self.parse_ident()?.to_string());
+                            self.skip_spaces();
+                        } else {
+                            break;
+                        }
+                    }
+
+                    let joined = idents.join(" ");
+
+                    // TODO: No CSS keyword must be matched as a family name...
+                    match joined.as_str() {
+                        "serif" => FontFamily::Serif,
+                        "sans-serif" => FontFamily::SansSerif,
+                        "cursive" => FontFamily::Cursive,
+                        "fantasy" => FontFamily::Fantasy,
+                        "monospace" => FontFamily::Monospace,
+                        _ => FontFamily::Named(joined),
+                    }
+                }
+            };
+
+            families.push(family);
+
+            if let Ok(b) = self.curr_byte() {
+                if b == b',' {
+                    self.advance(1);
+                } else {
+                    break;
+                }
+            }
+        }
+
+        let families = families
+            .into_iter()
+            .filter(|f| match f {
+                FontFamily::Named(s) => !s.is_empty(),
+                _ => true,
+            })
+            .collect();
+
+        Ok(families)
+    }
+}
+
+#[rustfmt::skip]
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    macro_rules! test {
+        ($name:ident, $text:expr, $result:expr) => (
+            #[test]
+            fn $name() {
+                assert_eq!(parse_font_families($text).unwrap(), $result);
+            }
+        )
+    }
+
+    macro_rules! named {
+        ($text:expr) => (
+            FontFamily::Named($text.to_string())
+        )
+    }
+
+    const SERIF: FontFamily = FontFamily::Serif;
+    const SANS_SERIF: FontFamily = FontFamily::SansSerif;
+    const FANTASY: FontFamily = FontFamily::Fantasy;
+    const MONOSPACE: FontFamily = FontFamily::Monospace;
+    const CURSIVE: FontFamily = FontFamily::Cursive;
+
+    test!(font_family_1, "Times New Roman", vec![named!("Times New Roman")]);
+    test!(font_family_2, "serif", vec![SERIF]);
+    test!(font_family_3, "sans-serif", vec![SANS_SERIF]);
+    test!(font_family_4, "cursive", vec![CURSIVE]);
+    test!(font_family_5, "fantasy", vec![FANTASY]);
+    test!(font_family_6, "monospace", vec![MONOSPACE]);
+    test!(font_family_7, "'Times New Roman'", vec![named!("Times New Roman")]);
+    test!(font_family_8, "'Times New Roman', sans-serif", vec![named!("Times New Roman"), SANS_SERIF]);
+    test!(font_family_9, "'Times New Roman', sans-serif", vec![named!("Times New Roman"), SANS_SERIF]);
+    test!(font_family_10, "Arial, sans-serif, 'fantasy'", vec![named!("Arial"), SANS_SERIF, named!("fantasy")]);
+    test!(font_family_11, "    Arial  , monospace  , 'fantasy'", vec![named!("Arial"), MONOSPACE, named!("fantasy")]);
+    test!(font_family_12, "Times    New Roman", vec![named!("Times New Roman")]);
+    test!(font_family_13, "\"Times New Roman\", sans-serif, sans-serif, \"Arial\"",
+        vec![named!("Times New Roman"), SANS_SERIF, SANS_SERIF, named!("Arial")]
+    );
+    test!(font_family_14, "Times New Roman,,,Arial", vec![named!("Times New Roman"), named!("Arial")]);
+    test!(font_family_15, "简体中文,sans-serif  , ,\"日本語フォント\",Arial",
+        vec![named!("简体中文"), SANS_SERIF, named!("日本語フォント"), named!("Arial")]);
+
+    test!(font_family_16, "", vec![]);
+
+    macro_rules! font_family_err {
+        ($name:ident, $text:expr, $result:expr) => (
+            #[test]
+            fn $name() {
+                assert_eq!(parse_font_families($text).unwrap_err().to_string(), $result);
+            }
+        )
+    }
+    font_family_err!(font_family_err_1, "Red/Black, sans-serif", "invalid ident");
+    font_family_err!(font_family_err_2, "\"Lucida\" Grande, sans-serif", "unexpected data at position 10");
+    font_family_err!(font_family_err_3, "Ahem!, sans-serif", "invalid ident");
+    font_family_err!(font_family_err_4, "test@foo, sans-serif", "invalid ident");
+    font_family_err!(font_family_err_5, "#POUND, sans-serif", "invalid ident");
+    font_family_err!(font_family_err_6, "Hawaii 5-0, sans-serif", "invalid ident");
+}

src/lib.rs

@@ -70,6 +70,7 @@ mod directional_position;
 mod enable_background;
 mod error;
 mod filter_functions;
+mod font;
 mod funciri;
 mod length;
 mod number;
@@ -91,6 +92,7 @@ pub use crate::directional_position::*;
 pub use crate::enable_background::*;
 pub use crate::error::*;
 pub use crate::filter_functions::*;
+pub use crate::font::*;
 pub use crate::funciri::*;
 pub use crate::length::*;
 pub use crate::number::*;

src/paint_order.rs

@@ -60,7 +60,7 @@ impl std::str::FromStr for PaintOrder {
         let mut s = Stream::from(text);
         while !s.at_end() && order.len() < 3 {
             s.skip_spaces();
-            let name = s.consume_ident();
+            let name = s.consume_ascii_ident();
             s.skip_spaces();
             let name = match name {
                 // `normal` is the special value that should short-circuit.