rizzoo 0.6.9

a cross platform color generation tool implementing Material 3 Expressive
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

use winnow::combinator::{alt, delimited, opt, preceded, repeat, separated};
use winnow::prelude::*;
use winnow::token::{literal, take_while};

#[derive(Debug, Clone, PartialEq)]
pub enum TemplateNode {
    Text(String),
    Variable {
        name: String,
        filters: Vec<FilterCall>,
    },
}

#[derive(Debug, Clone, PartialEq)]
pub struct FilterCall {
    pub name: String,
    pub args: Vec<FilterArg>,
}

#[derive(Debug, Clone, PartialEq)]
pub enum FilterArg {
    Number(f64),
    String(String),
    Variable(String),
}

fn identifier(input: &mut &str) -> ModalResult<String> {
    take_while(1.., |c: char| c.is_alphanumeric() || c == '_')
        .map(|s: &str| s.to_string())
        .parse_next(input)
}

fn number_arg(input: &mut &str) -> ModalResult<FilterArg> {
    winnow::ascii::float
        .map(FilterArg::Number)
        .parse_next(input)
}

fn string_arg(input: &mut &str) -> ModalResult<FilterArg> {
    delimited(
        literal("\""),
        take_while(0.., |c: char| c != '"').map(|s: &str| s.to_string()),
        literal("\""),
    )
    .map(FilterArg::String)
    .parse_next(input)
}

fn bare_arg(input: &mut &str) -> ModalResult<FilterArg> {
    preceded(literal("%"), identifier.map(FilterArg::Variable)).parse_next(input)
}

fn filter_arg(input: &mut &str) -> ModalResult<FilterArg> {
    alt((
        number_arg,
        string_arg,
        bare_arg,
        identifier.map(FilterArg::String),
    ))
    .parse_next(input)
}

fn filter_args(input: &mut &str) -> ModalResult<Vec<FilterArg>> {
    delimited(
        literal("("),
        separated(
            0..,
            filter_arg,
            take_while(1.., |c: char| c.is_whitespace() || c == ','),
        ),
        literal(")"),
    )
    .parse_next(input)
}

fn filter_call(input: &mut &str) -> ModalResult<FilterCall> {
    let _ = literal(":").parse_next(input)?;
    let name = identifier.parse_next(input)?;
    let args = opt(filter_args).parse_next(input)?.unwrap_or_default();
    Ok(FilterCall { name, args })
}

fn variable_node(input: &mut &str) -> ModalResult<TemplateNode> {
    let _ = literal("{{").parse_next(input)?;
    let _ = take_while(0.., |c: char| c.is_whitespace()).parse_next(input)?;
    let name = identifier.parse_next(input)?;
    let filters = repeat(0.., filter_call).parse_next(input)?;
    let _ = take_while(0.., |c: char| c.is_whitespace()).parse_next(input)?;
    let _ = literal("}}").parse_next(input)?;
    Ok(TemplateNode::Variable { name, filters })
}

// Hand-rolled character scanner for raw text between template tags.
// Consumes characters until it finds `{{`, tracking byte positions manually
// so the remaining input slice is correctly positioned after extraction.
fn text_node(input: &mut &str) -> ModalResult<TemplateNode> {
    let original = *input;
    let mut consumed = 0usize;

    for c in input.chars() {
        if c == '{' {
            let rest = &input[consumed + 1..];
            if rest.starts_with('{') {
                break;
            }
        }
        consumed += c.len_utf8();
    }

    if consumed == 0 {
        return Err(winnow::error::ErrMode::Backtrack(
            winnow::error::ContextError::new(),
        ));
    }

    let text: String = original.chars().take(consumed).collect();
    *input = &original[consumed..];
    Ok(TemplateNode::Text(text))
}

fn template_node(input: &mut &str) -> ModalResult<TemplateNode> {
    alt((variable_node, text_node)).parse_next(input)
}

pub struct TemplateParser;

impl TemplateParser {
    pub fn parse(input: &str) -> Result<Vec<TemplateNode>, String> {
        if input.is_empty() {
            return Ok(vec![TemplateNode::Text(String::new())]);
        }
        repeat(1.., template_node).parse(input).map_err(
            |e: winnow::error::ParseError<&str, winnow::error::ContextError>| {
                format!("parse error: {e}")
            },
        )
    }
}