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mentioned matches_maybe

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Steve Donovan 2017-04-20 16:18:50 +02:00
parent 8681bb5f8c
commit 2480294ad5
1 changed files with 16 additions and 7 deletions
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readme.md
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@ -54,16 +54,25 @@ the first match and works from there. The 0 capture always exists
> There is an obvious limitation: "%a" refers specifically to a single byte
> representing a letter according to the C locale. Lua people will often
> look for 'sequence of non-spaces' ("%S+"), etc - that is, identify maybe-UTF-8
> sequences using surronding punctionation or spaces.
> sequences using surronding punctuation or spaces.
If you want your captures as strings, then there are several options. Grab them
as a vector (it will be empty if the match fails.)
If you want your captures as strings, then there are several options. If there's
just one, then `match_maybe` is useful:
```rust
let mut m = LuaPattern::new("OK%s+(%d+)");
let res = m.match_maybe("and that's OK 400 to you");
assert_eq!(res, Some("400"));
```
You can grab them as a vector (it will be empty if the match fails.)
```rust
let mut m = LuaPattern::new("(%a+) one");
let text = " hello one two";
let v = m.captures(text);
assert_eq!(v, &["hello one","hello"]);
```
This will create a vector - you can avoid excessive allocations with `capture_into`:
This will create a vector. You can avoid excessive allocations with `capture_into`:
```rust
let mut v = Vec::new();
@ -112,9 +121,9 @@ assert_eq!(res, "hellodollyyou'resofine");
let mut m = LuaPattern::new("(%S+)%s*=%s*(%S+);%s*");
let res = m.gsub("a=2; b=3; c = 4;", "'%2':%1 ");
assert_eq!(res, "'2':a '3':b '4':c ");
```
```
The third form of `string.gsub` in Lua does lookup with a table - that is, a map.
But for maps, you usually want to handle the 'not found' case in some special way:
But for maps you really want to handle the 'not found' case in some special way:
```rust
let mut map = HashMap::new();
@ -169,7 +178,7 @@ include one of the special matching characters like `$` (which is 0x24)
and so on. Hence there is `LuaPatternBuilder`:
```rust
let bytes = &[0xFF,0xEE,0x0,0xDE,0x24,0x24,0xBE,0x0,0x0];
let bytes = &[0xFF,0xEE,0x0,0xDE,0x24,0x24,0xBE,0x0,0x0];
let patt = LuaPatternBuilder::new()
.bytes_as_hex("DE24") // less tedious than a byte slice