7 to compute a needle hash and zip through the haystack when compared to
45 /// a pre-computed needle hash.
55     let mut hash = Hash::from_bytes_fwd(&haystack[..needle.len()]);  in find_with()  localVariable
59         if nhash.eq(hash) && is_prefix(haystack, needle) {  in find_with()
65         hash.roll(&nhash, haystack[0], haystack[needle.len()]);  in find_with()
76 /// a pre-computed needle hash.
85     let mut hash =  in rfind_with()  localVariable
86         Hash::from_bytes_rev(&haystack[haystack.len() - needle.len()..]);  in rfind_with()
88         if nhash.eq(hash) && is_suffix(haystack, needle) {  in rfind_with()
94         hash.roll(  in rfind_with()
103 /// A hash derived from a needle.
106     /// The actual hash.
107     hash: Hash,  field
109     /// the hash. It is defined to be 2^(n-1) (using wrapping exponentiation),
111     /// from the hash once the hash window rolls past it.
116     /// Create a new Rabin-Karp hash for the given needle for use in forward
119         let mut nh = NeedleHash { hash: Hash::new(), hash_2pow: 1 };  in forward()
123         nh.hash.add(needle[0]);  in forward()
125             nh.hash.add(b);  in forward()
131     /// Create a new Rabin-Karp hash for the given needle for use in reverse
134         let mut nh = NeedleHash { hash: Hash::new(), hash_2pow: 1 };  in reverse()
138         nh.hash.add(needle[needle.len() - 1]);  in reverse()
140             nh.hash.add(b);  in reverse()
147     fn eq(&self, hash: Hash) -> bool {  in eq()
148         self.hash == hash  in eq()
152 /// A Rabin-Karp hash. This might represent the hash of a needle, or the hash
155 pub(crate) struct Hash(u32);  struct
157 impl Hash {  impl
158     /// Create a new hash that represents the empty string.
159     pub(crate) fn new() -> Hash {  in new()
160         Hash(0)  in new()
163     /// Create a new hash from the bytes given for use in forward searches.
164     pub(crate) fn from_bytes_fwd(bytes: &[u8]) -> Hash {  in from_bytes_fwd()  argument
165         let mut hash = Hash::new();  in from_bytes_fwd()  localVariable
167             hash.add(b);  in from_bytes_fwd()
169         hash  in from_bytes_fwd()
172     /// Create a new hash from the bytes given for use in reverse searches.
173     fn from_bytes_rev(bytes: &[u8]) -> Hash {  in from_bytes_rev()  argument
174         let mut hash = Hash::new();  in from_bytes_rev()  localVariable
176             hash.add(b);  in from_bytes_rev()
178         hash  in from_bytes_rev()
181     /// Add 'new' and remove 'old' from this hash. The given needle hash should
182     /// correspond to the hash computed for the needle being searched for.
191     /// Add a byte to this hash.
196     /// Remove a byte from this hash. The given needle hash should correspond
197     /// to the hash computed for the needle being searched for.