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-rw-r--r--crates/ra_syntax/src/lexer/numbers.rs67
1 files changed, 67 insertions, 0 deletions
diff --git a/crates/ra_syntax/src/lexer/numbers.rs b/crates/ra_syntax/src/lexer/numbers.rs
new file mode 100644
index 000000000..22e7d4e99
--- /dev/null
+++ b/crates/ra_syntax/src/lexer/numbers.rs
@@ -0,0 +1,67 @@
1use lexer::classes::*;
2use lexer::ptr::Ptr;
3
4use SyntaxKind::{self, *};
5
6pub(crate) fn scan_number(c: char, ptr: &mut Ptr) -> SyntaxKind {
7 if c == '0' {
8 match ptr.current().unwrap_or('\0') {
9 'b' | 'o' => {
10 ptr.bump();
11 scan_digits(ptr, false);
12 }
13 'x' => {
14 ptr.bump();
15 scan_digits(ptr, true);
16 }
17 '0'...'9' | '_' | '.' | 'e' | 'E' => {
18 scan_digits(ptr, true);
19 }
20 _ => return INT_NUMBER,
21 }
22 } else {
23 scan_digits(ptr, false);
24 }
25
26 // might be a float, but don't be greedy if this is actually an
27 // integer literal followed by field/method access or a range pattern
28 // (`0..2` and `12.foo()`)
29 if ptr.at('.') && !(ptr.at_str("..") || ptr.nth_is_p(1, is_ident_start)) {
30 // might have stuff after the ., and if it does, it needs to start
31 // with a number
32 ptr.bump();
33 scan_digits(ptr, false);
34 scan_float_exponent(ptr);
35 return FLOAT_NUMBER;
36 }
37 // it might be a float if it has an exponent
38 if ptr.at('e') || ptr.at('E') {
39 scan_float_exponent(ptr);
40 return FLOAT_NUMBER;
41 }
42 INT_NUMBER
43}
44
45fn scan_digits(ptr: &mut Ptr, allow_hex: bool) {
46 while let Some(c) = ptr.current() {
47 match c {
48 '_' | '0'...'9' => {
49 ptr.bump();
50 }
51 'a'...'f' | 'A'...'F' if allow_hex => {
52 ptr.bump();
53 }
54 _ => return,
55 }
56 }
57}
58
59fn scan_float_exponent(ptr: &mut Ptr) {
60 if ptr.at('e') || ptr.at('E') {
61 ptr.bump();
62 if ptr.at('-') || ptr.at('+') {
63 ptr.bump();
64 }
65 scan_digits(ptr, false);
66 }
67}