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authorAleksey Kladov <[email protected]>2018-07-31 21:38:19 +0100
committerAleksey Kladov <[email protected]>2018-07-31 21:44:31 +0100
commit7912189ec304b28c4df0030b5282cf3d21074154 (patch)
tree03a0a1b128439fdefbd1d012b392995ca8a6e264 /src/grammar/items/use_item.rs
parentd1400e95d7ad701fcba1191cb00968c2eae8b394 (diff)
reorganize
Diffstat (limited to 'src/grammar/items/use_item.rs')
-rw-r--r--src/grammar/items/use_item.rs66
1 files changed, 66 insertions, 0 deletions
diff --git a/src/grammar/items/use_item.rs b/src/grammar/items/use_item.rs
new file mode 100644
index 000000000..a3f7f0da8
--- /dev/null
+++ b/src/grammar/items/use_item.rs
@@ -0,0 +1,66 @@
1use super::*;
2
3pub(super) fn use_item(p: &mut Parser) {
4 assert!(p.at(USE_KW));
5 p.bump();
6 use_tree(p);
7 p.expect(SEMI);
8}
9
10fn use_tree(p: &mut Parser) {
11 let la = p.nth(1);
12 let m = p.start();
13 match (p.current(), la) {
14 (STAR, _) => p.bump(),
15 (COLONCOLON, STAR) => {
16 p.bump();
17 p.bump();
18 }
19 (L_CURLY, _) | (COLONCOLON, L_CURLY) => {
20 if p.at(COLONCOLON) {
21 p.bump();
22 }
23 nested_trees(p);
24 }
25 _ if paths::is_path_start(p) => {
26 paths::use_path(p);
27 match p.current() {
28 AS_KW => {
29 alias(p);
30 }
31 COLONCOLON => {
32 p.bump();
33 match p.current() {
34 STAR => {
35 p.bump();
36 }
37 L_CURLY => nested_trees(p),
38 _ => {
39 // is this unreachable?
40 p.error("expected `{` or `*`");
41 }
42 }
43 }
44 _ => (),
45 }
46 }
47 _ => {
48 m.abandon(p);
49 p.err_and_bump("expected one of `*`, `::`, `{`, `self`, `super`, `indent`");
50 return;
51 }
52 }
53 m.complete(p, USE_TREE);
54}
55
56fn nested_trees(p: &mut Parser) {
57 assert!(p.at(L_CURLY));
58 p.bump();
59 while !p.at(EOF) && !p.at(R_CURLY) {
60 use_tree(p);
61 if !p.at(R_CURLY) {
62 p.expect(COMMA);
63 }
64 }
65 p.expect(R_CURLY);
66}