#
# This file is free software, which comes along with NIT. This software is
# distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE. You can modify it is you want, provided this header
# is kept unaltered, and a notification of the changes is added.
# You are allowed to redistribute it and sell it, alone or is a part of
# another product.
# Basic string search, match and replace.
-package string_search
+module string_search
import string
# Search `self` into `s` from a certain position.
# Return the position of the first character of the matching section.
# Return -1 if not found.
- fun search_index_in(s: String, from: Int): Int is abstract
+ #
+ # assert 'l'.search_index_in("hello world", 0) == 2
+ # assert 'l'.search_index_in("hello world", 3) == 3
+ # assert 'z'.search_index_in("hello world", 0) == -1
+ #
+ # This method is usually faster than `search_in` if what is
+ # required is only the index.
+ # Note: in most implementation, `search_in` is implemented with this method.
+ protected fun search_index_in(s: String, from: Int): Int is abstract
# Search `self` into `s` from a certain position.
# Return null if not found.
- fun search_in(s: String, from: Int): nullable Match is abstract
+ #
+ # assert 'l'.search_in("hello world", 0).from == 2
+ # assert 'l'.search_in("hello world", 3).from == 3
+ # assert 'z'.search_in("hello world", 0) == null
+ #
+ # If only the index of the first character if required, see `search_index_in`.
+ #
+ # Note: Is used by `String::search`, `String::search_from`, and others.
+ protected fun search_in(s: String, from: Int): nullable Match is abstract
# Search all `self` occurrences into `s`.
+ #
+ # assert 'l'.search_all_in("hello world").length == 3
+ # assert 'z'.search_all_in("hello world"),length == 0
+ #
+ # Note: Is used by `String::search_all`.
fun search_all_in(s: String): Array[Match]
do
var res = new Array[Match] # Result
end
# Split `s` using `self` is separator.
+ #
+ # Returns an array of matches that are between each occurence of `self`.
+ # If self is not present, an array with a single match on `s` is retunred.
+ #
+ # assert 'l'.split_in("hello world").join("|") == "he||o wor|d"
+ # assert 'z'.split_in("hello world").join("|") == "hello world"
+ #
+ # Note: is used by `String::split`
fun split_in(s: String): Array[Match]
do
var res = new Array[Match] # Result
# (cf. A Fast String Searching Algorithm, with R.S. Boyer. Communications
# of the Association for Computing Machinery, 20(10), 1977, pp. 762-772.)
# http://www.cs.utexas.edu/users/moore/best-ideas/string-searching/index.html
+#
+# var pat = new BM_Pattern("hello")
+# assert "I say hello to the world!".search(pat).from == 6
+# assert "I say goodbye to the world!".search(pat) == null
class BM_Pattern
super Pattern
var j = from
while j < n - m + 1 do
var i = m - 1 # Cursor in the pattern
- while i >= 0 and _motif[i] == s[i + j] do i -= 1
+ while i >= 0 and _motif.chars[i] == s.chars[i + j] do i -= 1
if i < 0 then
return j
else
var gs = _gs[i] # Good shift
- var bc = bc(s[i+j]) - m + 1 + i # Bad char
+ var bc = bc(s.chars[i+j]) - m + 1 + i # Bad char
# Both are true, do move to the best
if gs > bc then
j += gs
var _length: Int
private fun bc(e: Char): Int
- do
+ do
if _bc_table.has_key(e) then
return _bc_table[e]
else
var m = _length
var i = 0
while i < m - 1 do
- _bc_table[x[i]] = m - i - 1
+ _bc_table[x.chars[i]] = m - i - 1
i += 1
end
end
else
if i < g then g = i
f = i
- while g >= 0 and x[g] == x[g + m - 1 - f] do g -= 1
+ while g >= 0 and x.chars[g] == x.chars[g + m - 1 - f] do g -= 1
suff[i] = f - g
end
i -= 1
i += 1
end
end
+
+ redef fun hash do return _motif.hash
+ redef fun ==(o) do return o isa BM_Pattern and o._motif == _motif
end
-# Matches are a part of a string.
+# Matches are a part of a `String` found ba a `Pattern`.
class Match
# The base string matched
readable var _string: String
do
var stop = s.length
while from < stop do
- if s[from] == self then return from
+ if s.chars[from] == self then return from
from += 1
end
return -1
var stop = s.length - length + 1
while from < stop do
var i = length - 1
- while i >= 0 and self[i] == s[i + from] do i -= 1
+ while i >= 0 and self.chars[i] == s.chars[i + from] do i -= 1
# Test if we found
if i < 0 then return from
# Not found so try next one
end
end
- # Like `search_from` but from the first character.
+ # Search the first occurence of the pattern `p`.
+ # Return null if not found.
+ #
+ # assert "I say hello to the world!".search("hello").from == 6
+ # assert "I say goodbye to the world!".search("hello") == null
fun search(p: Pattern): nullable Match do return p.search_in(self, 0)
- # Search the given pattern into self from a.
+ # Search the first occurence of the pattern `p` after `from`.
# The search starts at `from`.
# Return null if not found.
+ #
+ # assert "I say hello to the world!".search_from("hello",4).from == 6
+ # assert "I say hello to the world!".search_from("hello",7) == null
fun search_from(p: Pattern, from: Int): nullable Match do return p.search_in(self, from)
# Search all occurrences of p into self.
# for i in "hello world".search_all('o') do
# a.add(i.from)
# end
- # a # -> [4, 7]
+ # assert a == [4, 7]
fun search_all(p: Pattern): Array[Match] do return p.search_all_in(self)
# Split `self` using `p` as separator.
#
- # "hello world".split('o') # -> ["hell", " w", "rld"]
+ # assert "hello world".split('o') == ["hell", " w", "rld"]
fun split(p: Pattern): Array[String]
do
var matches = p.split_in(self)
# Replace all occurences of a pattern with a string
#
- # "hlelo".replace("le", "el") # -> "hello"
- # "hello".replace('l', "") # -> "heo"
+ # assert "hlelo".replace("le", "el") == "hello"
+ # assert "hello".replace('l', "") == "heo"
fun replace(p: Pattern, string: String): String
do
return self.split_with(p).join(string)
end
- # Escape the four characters < > & and " with their html counterpart
+ # Escape the four characters `<`, `>`, `&`, and `"` with their html counterpart
#
- # "a&b->\"x\"".html_escape # -> "a&b->"x""
+ # assert "a&b->\"x\"".html_escape == "a&b->"x""
fun html_escape: String
do
var ret = self
- if ret.has('&') then ret = ret.replace('&', "&")
- if ret.has('<') then ret = ret.replace('<', "<")
- if ret.has('>') then ret = ret.replace('>', ">")
- if ret.has('"') then ret = ret.replace('"', """)
+ if ret.chars.has('&') then ret = ret.replace('&', "&")
+ if ret.chars.has('<') then ret = ret.replace('<', "<")
+ if ret.chars.has('>') then ret = ret.replace('>', ">")
+ if ret.chars.has('"') then ret = ret.replace('"', """)
return ret
end
end
nitlanguage / nit.git / blobdiff