rsass 0.29.2

Sass implementation in pure rust (not complete yet)
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
158
159
160
161
162
163
164
165

use super::super::util::ignore_comments;
use super::{opt_spacelike, spacelike, strings, values, PResult, Span};
use crate::css::{MediaArgs, Value};
use crate::value::{ListSeparator, Operator};
use nom::branch::alt;
use nom::bytes::complete::{tag, tag_no_case};
use nom::combinator::{map, value};
use nom::multi::{fold_many0, fold_many1, separated_list1};
use nom::sequence::{delimited, pair, preceded, terminated};
use nom::Parser as _;
use std::str::from_utf8;

pub fn args(input: Span) -> PResult<MediaArgs> {
    map(
        separated_list1(
            delimited(opt_spacelike, tag(","), spacelike),
            media_args_and,
        ),
        |v| {
            if v.len() == 1 {
                v.into_iter().next().unwrap()
            } else {
                MediaArgs::Comma(v)
            }
        },
    )
    .parse(input)
}
fn media_args_and(input: Span) -> PResult<MediaArgs> {
    map(
        separated_list1(
            delimited(opt_spacelike, tag_no_case("and"), ignore_comments),
            media_args_or,
        ),
        |v| {
            if v.len() == 1 {
                v.into_iter().next().unwrap()
            } else {
                MediaArgs::And(v)
            }
        },
    )
    .parse(input)
}

fn media_args_or(input: Span) -> PResult<MediaArgs> {
    map(
        separated_list1(
            delimited(opt_spacelike, tag_no_case("or"), ignore_comments),
            media_args_one,
        ),
        |v| {
            if v.len() == 1 {
                v.into_iter().next().unwrap()
            } else {
                MediaArgs::Or(v)
            }
        },
    )
    .parse(input)
}

fn media_args_one(input: Span) -> PResult<MediaArgs> {
    alt((
        map(
            pair(
                terminated(
                    alt((tag_no_case("not"), tag_no_case("only"))),
                    ignore_comments,
                ),
                media_args_one,
            ),
            |(op, a)| {
                MediaArgs::UnaryOp(
                    from_utf8(&op).unwrap().into(),
                    Box::new(a),
                )
            },
        ),
        map(strings::css_string, MediaArgs::Name),
        delimited(
            tag("("),
            alt((
                map(
                    pair(
                        terminated(strings::css_string, tag(": ")),
                        values::any,
                    ),
                    |(k, v)| MediaArgs::Condition(k, v),
                ),
                map(media_relation, MediaArgs::Range),
                map(args, |v| MediaArgs::Paren(Box::new(v))),
            )),
            preceded(opt_spacelike, tag(")")),
        ),
        delimited(
            tag("["),
            map(media_args_one, |v| MediaArgs::Bracket(Box::new(v))),
            tag("]"),
        ),
    ))
    .parse(input)
}

fn media_relation(input: Span) -> PResult<Vec<(Operator, Value)>> {
    let (rest, first) = media_value(input)?;
    fold_many1(
        pair(
            delimited(opt_spacelike, relational_operator, opt_spacelike),
            media_value,
        ),
        move || vec![(Operator::Equal, first.clone())],
        |mut acc, item| {
            acc.push(item);
            acc
        },
    )
    .parse(rest)
}

pub fn relational_operator(input: Span) -> PResult<Operator> {
    alt((
        value(Operator::Equal, tag("==")),
        value(Operator::EqualSingle, tag("=")),
        value(Operator::NotEqual, tag("!=")),
        value(Operator::GreaterE, tag(">=")),
        value(Operator::Greater, tag(">")),
        value(Operator::LesserE, tag("<=")),
        value(Operator::Lesser, tag("<")),
    ))
    .parse(input)
}

/// Any css value that is allowd in a media relation / range.
fn media_value(input: Span) -> PResult<Value> {
    alt((
        media_slash_list_no_space,
        delimited(
            terminated(tag("("), opt_spacelike),
            media_value,
            preceded(opt_spacelike, tag(")")),
        ),
    ))
    .parse(input)
}
pub fn media_slash_list_no_space(input: Span) -> PResult<Value> {
    let (input, first) = values::single(input)?;
    let (input, list) = fold_many0(
        preceded(tag("/"), values::single),
        move || vec![first.clone()],
        |mut list: Vec<Value>, item| {
            list.push(item);
            list
        },
    )
    .parse(input)?;
    Ok((
        input,
        if list.len() == 1 {
            list.into_iter().next().unwrap()
        } else {
            Value::List(list, Some(ListSeparator::SlashNoSpace), false)
        },
    ))
}