rizzoo 0.6.7

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
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226

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>,
    },
    ForBlock {
        var_name: String,
        collection: String,
        body: Vec<TemplateNode>,
    },
}

#[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 })
}

fn for_block_header(input: &mut &str) -> ModalResult<(String, String)> {
    let _ = literal("{{#").parse_next(input)?;
    let _ = take_while(0.., |c: char| c.is_whitespace()).parse_next(input)?;
    let _ = literal("for").parse_next(input)?;
    let _ = take_while(1.., |c: char| c.is_whitespace()).parse_next(input)?;
    let var_name = identifier.parse_next(input)?;
    let _ = take_while(1.., |c: char| c.is_whitespace()).parse_next(input)?;
    let _ = literal("in").parse_next(input)?;
    let _ = take_while(1.., |c: char| c.is_whitespace()).parse_next(input)?;
    let collection = identifier.parse_next(input)?;
    let _ = take_while(0.., |c: char| c.is_whitespace()).parse_next(input)?;
    let _ = literal("}}").parse_next(input)?;
    Ok((var_name, collection))
}

// 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))
}

// Checks whether the text at `pos` matches a for-block close tag `{{/ var_name }}`.
// Handles arbitrary whitespace between `{{/`, the variable name, and `}}`.
fn match_close_tag(text: &str, var_name: &str, pos: usize) -> bool {
    let rest = &text[pos..];
    if !rest.starts_with("{{/") {
        return false;
    }
    let after_slash = &rest[3..];
    let trimmed = after_slash.trim_start();
    if let Some(stripped) = trimmed.strip_prefix(var_name) {
        stripped.trim_start().starts_with("}}")
    } else {
        false
    }
}

// Parses `{{# for <var> in <collection> }}...{{/ <var> }}` blocks.
// Uses depth tracking to handle nested for blocks — increments on `{{#`,
// decrements on matching `{{/ <var> }}`, and only closes when depth reaches 0.
// This means nested blocks with the same variable name will incorrectly close
// the outer block first; real nesting with different variables works correctly.
//
// depth-based close tag matching works for distinct vars but fails
// for same-variable nesting. Add full stack tracking if that pattern is needed.
fn for_block(input: &mut &str) -> ModalResult<TemplateNode> {
    let (var_name, collection) = for_block_header.parse_next(input)?;

    let mut depth = 0i32;
    let mut close_pos = None;
    let bytes = input.as_bytes();

    for (i, _) in input.char_indices() {
        if i + 2 < bytes.len() && &input[i..i + 3] == "{{#" {
            depth += 1;
        } else if match_close_tag(input, &var_name, i) {
            if depth == 0 {
                close_pos = Some(i);
                break;
            }
            depth -= 1;
        }
    }

    let close_pos = close_pos
        .ok_or_else(|| winnow::error::ErrMode::Backtrack(winnow::error::ContextError::new()))?;

    let body_text = &input[..close_pos];
    let body = TemplateParser::parse(body_text).unwrap_or_default();

    let after_slash = &input[close_pos + 3..];
    let after_id = after_slash
        .trim_start()
        .strip_prefix(&var_name)
        .ok_or_else(|| winnow::error::ErrMode::Backtrack(winnow::error::ContextError::new()))?;
    let after_id = after_id.trim_start();
    let offset = after_id
        .find("}}")
        .ok_or_else(|| winnow::error::ErrMode::Backtrack(winnow::error::ContextError::new()))?;

    *input = &after_id[offset + 2..];

    Ok(TemplateNode::ForBlock {
        var_name,
        collection,
        body,
    })
}

fn template_node(input: &mut &str) -> ModalResult<TemplateNode> {
    alt((for_block, 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}")
            },
        )
    }
}