grass/src/style.rs
2020-01-25 09:58:53 -05:00

67 lines
2.0 KiB
Rust

use crate::common::{Scope, Symbol};
use crate::utils::{devour_whitespace_or_comment, eat_interpolation};
use crate::value::Value;
use crate::{Token, TokenKind};
use std::fmt::{self, Display};
use std::iter::Peekable;
use std::vec::IntoIter;
/// A style: `color: red`
#[derive(Clone, Debug, Eq, PartialEq)]
pub(crate) struct Style {
property: String,
value: Value,
}
impl Display for Style {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}: {};", self.property, self.value)
}
}
impl Style {
pub fn from_tokens(tokens: Vec<Token>, scope: &Scope) -> Result<Self, ()> {
Ok(StyleParser::new(tokens, scope)?.parse())
}
}
struct StyleParser<'a> {
tokens: Peekable<IntoIter<Token>>,
scope: &'a Scope,
}
impl<'a> StyleParser<'a> {
fn new(tokens: Vec<Token>, scope: &'a Scope) -> Result<Self, ()> {
if tokens.is_empty() {
return Err(());
}
let tokens = tokens.into_iter().peekable();
Ok(StyleParser { tokens, scope })
}
fn parse(&mut self) -> Style {
let mut property = String::new();
// read property until `:`
while let Some(Token { kind, .. }) = self.tokens.next() {
match kind {
TokenKind::Whitespace(_) | TokenKind::MultilineComment(_) => continue,
TokenKind::Ident(ref s) => property.push_str(s),
TokenKind::Interpolation => property.push_str(
&eat_interpolation(&mut self.tokens, self.scope)
.iter()
.map(|x| x.kind.to_string())
.collect::<String>(),
),
TokenKind::Symbol(Symbol::Colon) => break,
_ => property.push_str(&kind.to_string()),
};
}
devour_whitespace_or_comment(&mut self.tokens);
let value = Value::from_tokens(&mut self.tokens, self.scope).unwrap();
Style { property, value }
}
}