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
|
use crate::kw;
use crate::parser::{Cursor, Parse, Parser, Peek, Result};
use crate::token::{Float32, Float64};
/// Expression that can be used inside of `invoke` expressions for core wasm
/// functions.
#[derive(Debug)]
#[allow(missing_docs)]
pub enum WastVal<'a> {
Bool(bool),
U8(u8),
S8(i8),
U16(u16),
S16(i16),
U32(u32),
S32(i32),
U64(u64),
S64(i64),
Float32(Float32),
Float64(Float64),
Char(char),
String(&'a str),
List(Vec<WastVal<'a>>),
Record(Vec<(&'a str, WastVal<'a>)>),
Tuple(Vec<WastVal<'a>>),
Variant(&'a str, Option<Box<WastVal<'a>>>),
Enum(&'a str),
Option(Option<Box<WastVal<'a>>>),
Result(Result<Option<Box<WastVal<'a>>>, Option<Box<WastVal<'a>>>>),
Flags(Vec<&'a str>),
}
static CASES: &[(&str, fn(Parser<'_>) -> Result<WastVal<'_>>)] = {
use WastVal::*;
&[
("bool.const", |p| {
let mut l = p.lookahead1();
if l.peek::<kw::true_>()? {
p.parse::<kw::true_>()?;
Ok(Bool(true))
} else if l.peek::<kw::false_>()? {
p.parse::<kw::false_>()?;
Ok(Bool(false))
} else {
Err(l.error())
}
}),
("u8.const", |p| Ok(U8(p.parse()?))),
("s8.const", |p| Ok(S8(p.parse()?))),
("u16.const", |p| Ok(U16(p.parse()?))),
("s16.const", |p| Ok(S16(p.parse()?))),
("u32.const", |p| Ok(U32(p.parse()?))),
("s32.const", |p| Ok(S32(p.parse()?))),
("u64.const", |p| Ok(U64(p.parse()?))),
("s64.const", |p| Ok(S64(p.parse()?))),
("f32.const", |p| Ok(Float32(p.parse()?))),
("f64.const", |p| Ok(Float64(p.parse()?))),
("char.const", |p| {
let s = p.parse::<&str>()?;
let mut ch = s.chars();
let ret = match ch.next() {
Some(c) => c,
None => return Err(p.error("empty string")),
};
if ch.next().is_some() {
return Err(p.error("more than one character"));
}
Ok(Char(ret))
}),
("str.const", |p| Ok(String(p.parse()?))),
("list.const", |p| {
let mut ret = Vec::new();
while !p.is_empty() {
ret.push(p.parens(|p| p.parse())?);
}
Ok(List(ret))
}),
("record.const", |p| {
let mut ret = Vec::new();
while !p.is_empty() {
ret.push(p.parens(|p| {
p.parse::<kw::field>()?;
Ok((p.parse()?, p.parse()?))
})?);
}
Ok(Record(ret))
}),
("tuple.const", |p| {
let mut ret = Vec::new();
while !p.is_empty() {
ret.push(p.parens(|p| p.parse())?);
}
Ok(Tuple(ret))
}),
("variant.const", |p| {
let name = p.parse()?;
let payload = if p.is_empty() {
None
} else {
Some(Box::new(p.parens(|p| p.parse())?))
};
Ok(Variant(name, payload))
}),
("enum.const", |p| Ok(Enum(p.parse()?))),
("option.none", |_| Ok(Option(None))),
("option.some", |p| {
Ok(Option(Some(Box::new(p.parens(|p| p.parse())?))))
}),
("result.ok", |p| {
Ok(Result(Ok(if p.is_empty() {
None
} else {
Some(Box::new(p.parens(|p| p.parse())?))
})))
}),
("result.err", |p| {
Ok(Result(Err(if p.is_empty() {
None
} else {
Some(Box::new(p.parens(|p| p.parse())?))
})))
}),
("flags.const", |p| {
let mut ret = Vec::new();
while !p.is_empty() {
ret.push(p.parse()?);
}
Ok(Flags(ret))
}),
]
};
impl<'a> Parse<'a> for WastVal<'a> {
fn parse(parser: Parser<'a>) -> Result<Self> {
parser.depth_check()?;
let parse = parser.step(|c| {
if let Some((kw, rest)) = c.keyword()? {
if let Some(i) = CASES.iter().position(|(name, _)| *name == kw) {
return Ok((CASES[i].1, rest));
}
}
Err(c.error("expected a [type].const expression"))
})?;
parse(parser)
}
}
impl Peek for WastVal<'_> {
fn peek(cursor: Cursor<'_>) -> Result<bool> {
let kw = match cursor.keyword()? {
Some((kw, _)) => kw,
None => return Ok(false),
};
Ok(CASES.iter().any(|(name, _)| *name == kw))
}
fn display() -> &'static str {
"core wasm argument"
}
}
|
