skyscraper 0.7.0

XPath for HTML web scraping
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

//! <https://www.w3.org/TR/2017/REC-xpath-31-20170321/#id-literals>

use std::fmt::Display;

use nom::{branch::alt, error::context};

use crate::xpath::grammar::{
    data_model::AnyAtomicType,
    recipes::Res,
    terminal_symbols::{
        decimal_literal, double_literal, integer_literal, string_literal, StringLiteral,
    },
};

pub fn literal(input: &str) -> Res<&str, Literal> {
    // https://www.w3.org/TR/2017/REC-xpath-31-20170321/#prod-xpath31-Literal

    fn numeric_literal_map(input: &str) -> Res<&str, Literal> {
        numeric_literal(input).map(|(next_input, res)| (next_input, Literal::NumericLiteral(res)))
    }

    fn string_literal_map(input: &str) -> Res<&str, Literal> {
        string_literal(input).map(|(next_input, res)| (next_input, Literal::StringLiteral(res)))
    }

    context("literal", alt((numeric_literal_map, string_literal_map)))(input)
}

#[derive(PartialEq, Debug, Clone)]
pub enum Literal {
    NumericLiteral(NumericLiteral),
    StringLiteral(StringLiteral),
}

impl Display for Literal {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Literal::NumericLiteral(x) => write!(f, "{}", x),
            Literal::StringLiteral(x) => write!(f, "{}", x),
        }
    }
}

impl Literal {
    pub(crate) fn value(&self) -> AnyAtomicType {
        match self {
            Literal::NumericLiteral(numeric) => numeric.value(),
            Literal::StringLiteral(x) => AnyAtomicType::String(x.value.clone()),
        }
    }
}

pub fn numeric_literal(input: &str) -> Res<&str, NumericLiteral> {
    // https://www.w3.org/TR/2017/REC-xpath-31-20170321/#prod-xpath31-NumericLiteral

    fn integer_literal_map(input: &str) -> Res<&str, NumericLiteral> {
        integer_literal(input).map(|(next_input, res)| (next_input, NumericLiteral::Integer(res)))
    }

    fn decimal_literal_map(input: &str) -> Res<&str, NumericLiteral> {
        decimal_literal(input).map(|(next_input, res)| (next_input, NumericLiteral::Decimal(res)))
    }

    fn double_literal_map(input: &str) -> Res<&str, NumericLiteral> {
        double_literal(input).map(|(next_input, res)| (next_input, NumericLiteral::Double(res)))
    }

    context(
        "numeric_literal",
        alt((double_literal_map, decimal_literal_map, integer_literal_map)),
    )(input)
}

#[derive(PartialEq, Debug, Clone, Copy)]
pub enum NumericLiteral {
    Integer(u32),
    Decimal(f32),
    Double(f64),
}

impl Display for NumericLiteral {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            NumericLiteral::Integer(x) => write!(f, "{}", x),
            NumericLiteral::Decimal(x) => write!(f, "{}", x),
            NumericLiteral::Double(x) => write!(f, "{}", x),
        }
    }
}

impl NumericLiteral {
    pub(crate) fn value(&self) -> AnyAtomicType {
        match self {
            NumericLiteral::Integer(x) => AnyAtomicType::Integer((*x).into()),
            NumericLiteral::Decimal(x) => AnyAtomicType::Float(ordered_float::OrderedFloat(*x)),
            NumericLiteral::Double(x) => AnyAtomicType::Double(ordered_float::OrderedFloat(*x)),
        }
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn numeric_literal_should_match_decimal() {
        // arrange
        let input = "0.25";

        // act
        let (next_input, res) = numeric_literal(input).unwrap();

        // assert
        assert_eq!(next_input, "");
        assert_eq!(res.to_string(), "0.25");
    }

    #[test]
    fn numeric_literal_should_match_double() {
        // arrange
        let input = "1e+2";

        // act
        let (next_input, res) = numeric_literal(input).unwrap();

        // assert
        assert_eq!(next_input, "");
        assert_eq!(res.to_string(), "100");
    }

    #[test]
    fn numeric_literal_should_match_integer() {
        // arrange
        let input = "1";

        // act
        let (next_input, res) = numeric_literal(input).unwrap();

        // assert
        assert_eq!(next_input, "");
        assert_eq!(res.to_string(), "1");
    }
}