drt-sc-derive 0.0.2

Dharitri smart contract API procedural macros
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

const OPEN_BRACE: u8 = b'{';
const CLOSED_BRACE: u8 = b'}';
const TWO_DOTS: u8 = b':';
const X_LETTER: u8 = b'x';
const B_LETTER: u8 = b'b';
const C_LETTER: u8 = b'c';

const UNMATCHED_BRACE_ERR_MSG: &str = "Unmatched `{` in the format string";

#[derive(Debug, PartialEq, Eq)]
pub enum FormatPartType {
    StaticAscii(String),
    LowerHex,
    Display,
    Codec,
    Bytes,
}

pub fn parse_format_string(raw_string: &str) -> Vec<FormatPartType> {
    if !raw_string.is_ascii() {
        panic!("Only ASCII strings allowed");
    }

    let ascii_bytes = raw_string.as_bytes();
    let mut parts = Vec::new();
    let mut start_index = 1;
    let mut format_byte;

    // starting from 1 and up to len - 1 to skip the ""
    let str_len = ascii_bytes.len() - 1;
    for i in 1..str_len {
        if ascii_bytes[i] != OPEN_BRACE {
            continue;
        }

        match ascii_bytes.get(i + 1) {
            Some(byte) => match *byte {
                CLOSED_BRACE => {
                    if i > 1 {
                        let end_index = i - 1;
                        if start_index <= end_index {
                            let static_part = &ascii_bytes[start_index..=end_index];
                            let as_str = String::from_utf8(static_part.to_vec()).unwrap();
                            parts.push(FormatPartType::StaticAscii(as_str));
                        }
                    }

                    parts.push(FormatPartType::Display);

                    start_index = i + 2;
                },
                TWO_DOTS => {
                    match ascii_bytes.get(i + 2) {
                        Some(letter) => {
                            if *letter != X_LETTER && *letter != B_LETTER && *letter != C_LETTER {
                                panic!("{}", UNMATCHED_BRACE_ERR_MSG);
                            }
                            format_byte = letter;
                        },
                        None => panic!("{}", UNMATCHED_BRACE_ERR_MSG),
                    }
                    match ascii_bytes.get(i + 3) {
                        Some(closed_brace) => {
                            if *closed_brace != CLOSED_BRACE {
                                panic!("{}", UNMATCHED_BRACE_ERR_MSG);
                            }
                        },
                        None => panic!("{}", UNMATCHED_BRACE_ERR_MSG),
                    }

                    if i > 1 {
                        let end_index = i - 1;
                        if start_index != end_index {
                            let static_part = &ascii_bytes[start_index..=end_index];
                            let as_str = String::from_utf8(static_part.to_vec()).unwrap();
                            parts.push(FormatPartType::StaticAscii(as_str));
                        }
                    }
                    if *format_byte == X_LETTER {
                        parts.push(FormatPartType::LowerHex);
                    } else if *format_byte == B_LETTER {
                        parts.push(FormatPartType::Bytes);
                    } else if *format_byte == C_LETTER {
                        parts.push(FormatPartType::Codec);
                    }

                    start_index = i + 4;
                },
                _ => panic!("{}", UNMATCHED_BRACE_ERR_MSG),
            },
            None => panic!("{}", UNMATCHED_BRACE_ERR_MSG),
        }
    }

    if start_index < str_len {
        let static_part = &ascii_bytes[start_index..str_len];
        let as_str = String::from_utf8(static_part.to_vec()).unwrap();
        parts.push(FormatPartType::StaticAscii(as_str));
    }

    parts
}

pub(crate) fn count_args(format_types: &[FormatPartType]) -> usize {
    let mut nr_args = 0;
    for f in format_types {
        match *f {
            FormatPartType::Display => nr_args += 1,
            FormatPartType::LowerHex => nr_args += 1,
            FormatPartType::Codec => nr_args += 1,
            FormatPartType::Bytes => nr_args += 1,
            FormatPartType::StaticAscii(_) => {},
        }
    }

    nr_args
}

#[test]
fn test_format_parts_single_char_delimiter() {
    assert_eq!(
        parse_format_string("\"test{}/{}.json\""),
        vec![
            FormatPartType::StaticAscii("test".to_string()),
            FormatPartType::Display,
            FormatPartType::StaticAscii("/".to_string()),
            FormatPartType::Display,
            FormatPartType::StaticAscii(".json".to_string())
        ]
    );
}

#[test]
fn test_format_parts_no_delimiter() {
    assert_eq!(
        parse_format_string("\"{}{}.txt\""),
        vec![
            FormatPartType::Display,
            FormatPartType::Display,
            FormatPartType::StaticAscii(".txt".to_string())
        ]
    );
}

#[test]
fn test_format_parts_multiple_chars_between_displays() {
    assert_eq!(
        parse_format_string("\"{}test{}\""),
        vec![
            FormatPartType::Display,
            FormatPartType::StaticAscii("test".to_string()),
            FormatPartType::Display
        ]
    );
}