include-postgres-sql 0.2.2

A Yesql inspired macro for using PostgreSQL SQL in Rust
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

pub use ::include_sql::index_of;

#[macro_export]
#[doc(hidden)]
macro_rules! sql_literal {
    ($($name:ident)+ => $text:literal) => {
        $text
    };
    ($($name:ident)+ => $text:literal : $param:ident) => {
        ::std::concat!( $text, '$', $crate::util::index_of!($param in [ $( $name ),+ ] + 1) )
    };
    ($($name:ident)+ => $text:literal : $param:ident $($tail:tt)+) => {
        ::std::concat!(
            $text, '$', $crate::util::index_of!($param in [ $( $name ),+ ] + 1),
            $crate::sql_literal!($($name)+ => $($tail)+)
        )
    };
}

#[macro_export]
#[doc(hidden)]
macro_rules! num_args {
    () => { 0 };
    (: $head:ident $($tail:tt)*) => { 1 + $crate::num_args!($($tail)*) };
    (# $head:ident $($tail:tt)*) => { $head.len() + $crate::num_args!($($tail)*) };
}

#[macro_export]
#[doc(hidden)]
macro_rules! sql_len {
    () => { 0 };
    ($text:literal $($tail:tt)*) => { $text.len() + $crate::sql_len!($($tail)*) };
    (: $head:ident $($tail:tt)*) => { 3 + $crate::sql_len!($($tail)*) };
    (# $head:ident $($tail:tt)*) => { $head.len() * 5 + $crate::sql_len!($($tail)*) };
}

#[macro_export]
#[doc(hidden)]
macro_rules! dynamic_sql {
    ($stmt:ident $args:ident $i:ident) => {};
    ($stmt:ident $args:ident $i:ident $text:literal $($tail:tt)*) => {
        $stmt.push_str($text);
        $crate::dynamic_sql!($stmt $args $i $($tail)*);
    };
    ($stmt:ident $args:ident $i:ident : $param:ident $($tail:tt)*) => {
        $i += 1;
        $stmt.push_str(&::std::format!("${}", $i));
        $args.push(&$param);
        $crate::dynamic_sql!($stmt $args $i $($tail)*);
    };
    ($stmt:ident $args:ident $i:ident # $param:ident $($tail:tt)*) => {
        let mut iter = $param.into_iter();
        if let Some(arg) = iter.next() {
            $i += 1;
            $stmt.push_str(&::std::format!("${}", $i));
            $args.push(arg);
            while let Some(arg) = iter.next() {
                $i += 1;
                $stmt.push_str(&::std::format!(", ${}", $i));
                $args.push(arg);
            }
        } else {
            $stmt.push_str("NULL");
        }
        $crate::dynamic_sql!($stmt $args $i $($tail)*);
    };
}