X-Git-Url: http://nitlanguage.org diff --git a/lib/standard/string.nit b/lib/standard/string.nit index cc24265..48cb238 100644 --- a/lib/standard/string.nit +++ b/lib/standard/string.nit @@ -15,10 +15,12 @@ module string import math -intrude import collection # FIXME should be collection::array +import collection +intrude import collection::array `{ #include +#include `} ############################################################################### @@ -27,11 +29,22 @@ intrude import collection # FIXME should be collection::array # High-level abstraction for all text representations abstract class Text + super Comparable + + redef type OTHER: Text + + # Type of self (used for factorization of several methods, ex : substring_from, empty...) + type SELFTYPE: Text # Gets a view on the chars of the Text object - fun chars: StringCharView is abstract + # + # assert "hello".chars.to_a == ['h', 'e', 'l', 'l', 'o'] + fun chars: SequenceRead[Char] is abstract # Number of characters contained in self. + # + # assert "12345".length == 5 + # assert "".length == 0 fun length: Int is abstract # Create a substring. @@ -44,13 +57,23 @@ abstract class Text # A `from` index < 0 will be replaced by 0. # Unless a `count` value is > 0 at the same time. # In this case, `from += count` and `count -= from`. - fun substring(from: Int, count: Int): String is abstract + fun substring(from: Int, count: Int): SELFTYPE is abstract + + # Iterates on the substrings of self if any + fun substrings: Iterator[Text] is abstract # Is the current Text empty (== "") - # assert "".is_empty - # assert not "foo".is_empty + # + # assert "".is_empty + # assert not "foo".is_empty fun is_empty: Bool do return self.length == 0 + # Returns an empty Text of the right type + # + # This method is used internally to get the right + # implementation of an empty string. + protected fun empty: SELFTYPE is abstract + # Gets the first char of the Text # # DEPRECATED : Use self.chars.first instead @@ -88,6 +111,7 @@ abstract class Text var iter = self.chars.iterator_from(pos) while iter.is_ok do if iter.item == c then return iter.index + iter.next end return -1 end @@ -102,10 +126,14 @@ abstract class Text return last_index_of_from(c, length - 1) end + # Return a null terminated char * + fun to_cstring: NativeString do return flatten.to_cstring + # The index of the last occurrence of an element starting from pos (in reverse order). - # Example : - # assert "/etc/bin/test/test.nit".last_index_of_from('/', length-1) == 13 - # assert "/etc/bin/test/test.nit".last_index_of_from('/', 12) == 8 + # + # var s = "/etc/bin/test/test.nit" + # assert s.last_index_of_from('/', s.length-1) == 13 + # assert s.last_index_of_from('/', 12) == 8 # # Returns -1 if not found # @@ -128,13 +156,6 @@ abstract class Text return self.chars.iterator end - # Is 'c' contained in self ? - # - # DEPRECATED : Use self.chars.has instead - fun has(c: Char): Bool - do - return self.chars.has(c) - end # Gets an Array containing the chars of self # @@ -148,9 +169,10 @@ abstract class Text # assert "abcd".substring_from(2) == "cd" # # As with substring, a `from` index < 0 will be replaced by 0 - fun substring_from(from: Int): String + fun substring_from(from: Int): SELFTYPE do - assert from < length + if from >= self.length then return empty + if from < 0 then from = 0 return substring(from, length - from) end @@ -158,10 +180,27 @@ abstract class Text # # assert "abcd".has_substring("bc",1) == true # assert "abcd".has_substring("bc",2) == false + # + # Returns true iff all characters of `str` are presents + # at the expected index in `self.` + # The first character of `str` being at `pos`, the second + # character being at `pos+1` and so on... + # + # This means that all characters of `str` need to be inside `self`. + # + # assert "abcd".has_substring("xab", -1) == false + # assert "abcd".has_substring("cdx", 2) == false + # + # And that the empty string is always a valid substring. + # + # assert "abcd".has_substring("", 2) == true + # assert "abcd".has_substring("", 200) == true fun has_substring(str: String, pos: Int): Bool do + if str.is_empty then return true + if pos < 0 or pos + str.length > length then return false var myiter = self.chars.iterator_from(pos) - var itsiter = str.iterator + var itsiter = str.chars.iterator while myiter.is_ok and itsiter.is_ok do if myiter.item != itsiter.item then return false myiter.next @@ -206,6 +245,8 @@ abstract class Text end # If `self` contains only digits and alpha <= 'f', return the corresponding integer. + # + # assert "ff".to_hex == 255 fun to_hex: Int do return a_to(16) # If `self` contains only digits and letters, return the corresponding integer in a given base @@ -216,8 +257,8 @@ abstract class Text var i = 0 var neg = false - for c in self.chars - do + for j in [0..length[ do + var c = chars[j] var v = c.to_i if v > base then if neg then @@ -247,12 +288,10 @@ abstract class Text fun is_numeric: Bool do var has_point_or_comma = false - for i in self.chars - do - if not i.is_numeric - then - if (i == '.' or i == ',') and not has_point_or_comma - then + for i in [0..length[ do + var c = chars[i] + if not c.is_numeric then + if (c == '.' or c == ',') and not has_point_or_comma then has_point_or_comma = true else return false @@ -262,24 +301,81 @@ abstract class Text return true end - # A upper case version of `self` + # Returns `true` if the string contains only Hex chars # - # assert "Hello World!".to_upper == "HELLO WORLD!" - fun to_upper: String + # assert "048bf".is_hex == true + # assert "ABCDEF".is_hex == true + # assert "0G".is_hex == false + fun is_hex: Bool + do + for i in [0..length[ do + var c = chars[i] + if not (c >= 'a' and c <= 'f') and + not (c >= 'A' and c <= 'F') and + not (c >= '0' and c <= '9') then return false + end + return true + end + + # Are all letters in `self` upper-case ? + # + # assert "HELLO WORLD".is_upper == true + # assert "%$&%!".is_upper == true + # assert "hello world".is_upper == false + # assert "Hello World".is_upper == false + fun is_upper: Bool + do + for i in [0..length[ do + var char = chars[i] + if char.is_lower then return false + end + return true + end + + # Are all letters in `self` lower-case ? + # + # assert "hello world".is_lower == true + # assert "%$&%!".is_lower == true + # assert "Hello World".is_lower == false + fun is_lower: Bool + do + for i in [0..length[ do + var char = chars[i] + if char.is_upper then return false + end + return true + end + + # Removes the whitespaces at the beginning of self + # + # assert " \n\thello \n\t".l_trim == "hello \n\t" + # + # A whitespace is defined as any character which ascii value is less than or equal to 32 + fun l_trim: SELFTYPE do - var s = new Buffer.with_capacity(length) - for i in self.chars do s.add(i.to_upper) - return s.to_s + var iter = self.chars.iterator + while iter.is_ok do + if iter.item.ascii > 32 then break + iter.next + end + if iter.index == length then return self.empty + return self.substring_from(iter.index) end - # A lower case version of `self` + # Removes the whitespaces at the end of self # - # assert "Hello World!".to_lower == "hello world!" - fun to_lower : String + # assert " \n\thello \n\t".r_trim == " \n\thello" + # + # A whitespace is defined as any character which ascii value is less than or equal to 32 + fun r_trim: SELFTYPE do - var s = new Buffer.with_capacity(length) - for i in self.chars do s.add(i.to_lower) - return s.to_s + var iter = self.chars.reverse_iterator + while iter.is_ok do + if iter.item.ascii > 32 then break + iter.next + end + if iter.index < 0 then return self.empty + return self.substring(0, iter.index + 1) end # Trims trailing and preceding white spaces @@ -287,30 +383,42 @@ abstract class Text # # assert " Hello World ! ".trim == "Hello World !" # assert "\na\nb\tc\t".trim == "a\nb\tc" - fun trim: String - do - if self.length == 0 then return self.to_s - # find position of the first non white space char (ascii < 32) from the start of the string - var start_pos = 0 - while self.chars[start_pos].ascii <= 32 do - start_pos += 1 - if start_pos == length then return "" - end - # find position of the first non white space char from the end of the string - var end_pos = length - 1 - while self.chars[end_pos].ascii <= 32 do - end_pos -= 1 - if end_pos == start_pos then return self.chars[start_pos].to_s - end - return self.substring(start_pos, end_pos - start_pos + 1) + fun trim: SELFTYPE do return (self.l_trim).r_trim + + # Justify a self in a space of `length` + # + # `left` is the space ratio on the left side. + # * 0.0 for left-justified (no space at the left) + # * 1.0 for right-justified (all spaces at the left) + # * 0.5 for centered (half the spaces at the left) + # + # assert "hello".justify(10, 0.0) == "hello " + # assert "hello".justify(10, 1.0) == " hello" + # assert "hello".justify(10, 0.5) == " hello " + # + # If `length` is not enough, `self` is returned as is. + # + # assert "hello".justify(2, 0.0) == "hello" + # + # REQUIRE: left >= 0.0 and left <= 1.0 + # ENSURE: `self.length <= length implies result.length == length` + # ENSURE: `self.length >= length implies result == self + fun justify(length: Int, left: Float): SELFTYPE + do + var diff = length - self.length + if diff <= 0 then return self + assert left >= 0.0 and left <= 1.0 + var before = (diff.to_f * left).to_i + return " " * before + self + " " * (diff-before) end # Mangle a string to be a unique string only made of alphanumeric characters fun to_cmangle: String do - var res = new Buffer + var res = new FlatBuffer var underscore = false - for c in self.chars do + for i in [0..length[ do + var c = chars[i] if (c >= 'a' and c <= 'z') or (c >='A' and c <= 'Z') then res.add(c) underscore = false @@ -342,8 +450,9 @@ abstract class Text # assert "\n\"'\\".escape_to_c == "\\n\\\"\\'\\\\" fun escape_to_c: String do - var b = new Buffer - for c in self.chars do + var b = new FlatBuffer + for i in [0..length[ do + var c = chars[i] if c == '\n' then b.append("\\n") else if c == '\0' then @@ -369,8 +478,8 @@ abstract class Text # assert "ab|\{\}".escape_more_to_c("|\{\}") == "ab\\|\\\{\\\}" fun escape_more_to_c(chars: String): String do - var b = new Buffer - for c in escape_to_c do + var b = new FlatBuffer + for c in escape_to_c.chars do if chars.chars.has(c) then b.add('\\') end @@ -379,24 +488,68 @@ abstract class Text return b.to_s end - # Escape to c plus braces + # Escape to C plus braces # # assert "\n\"'\\\{\}".escape_to_nit == "\\n\\\"\\'\\\\\\\{\\\}" fun escape_to_nit: String do return escape_more_to_c("\{\}") + # Escape to POSIX Shell (sh). + # + # Abort if the text contains a null byte. + # + # assert "\n\"'\\\{\}0".escape_to_sh == "'\n\"'\\''\\\{\}0'" + fun escape_to_sh: String do + var b = new FlatBuffer + b.chars.add '\'' + for i in [0..length[ do + var c = chars[i] + if c == '\'' then + b.append("'\\''") + else + assert without_null_byte: c != '\0' + b.add(c) + end + end + b.chars.add '\'' + return b.to_s + end + + # Escape to include in a Makefile + # + # Unfortunately, some characters are not escapable in Makefile. + # These characters are `;`, `|`, `\`, and the non-printable ones. + # They will be rendered as `"?{hex}"`. + fun escape_to_mk: String do + var b = new FlatBuffer + for i in [0..length[ do + var c = chars[i] + if c == '$' then + b.append("$$") + else if c == ':' or c == ' ' or c == '#' then + b.add('\\') + b.add(c) + else if c.ascii < 32 or c == ';' or c == '|' or c == '\\' or c == '=' then + b.append("?{c.ascii.to_base(16, false)}") + else + b.add(c) + end + end + return b.to_s + end + # Return a string where Nit escape sequences are transformed. # - # Example: # var s = "\\n" # assert s.length == 2 # var u = s.unescape_nit # assert u.length == 1 - # assert u[0].ascii == 10 # (the ASCII value of the "new line" character) + # assert u.chars[0].ascii == 10 # (the ASCII value of the "new line" character) fun unescape_nit: String do - var res = new Buffer.with_capacity(self.length) + var res = new FlatBuffer.with_capacity(self.length) var was_slash = false - for c in self do + for i in [0..length[ do + var c = chars[i] if not was_slash then if c == '\\' then was_slash = true @@ -421,15 +574,188 @@ abstract class Text return res.to_s end + # Encode `self` to percent (or URL) encoding + # + # assert "aBc09-._~".to_percent_encoding == "aBc09-._~" + # assert "%()< >".to_percent_encoding == "%25%28%29%3c%20%3e" + # assert ".com/post?e=asdf&f=123".to_percent_encoding == ".com%2fpost%3fe%3dasdf%26f%3d123" + fun to_percent_encoding: String + do + var buf = new FlatBuffer + + for i in [0..length[ do + var c = chars[i] + if (c >= '0' and c <= '9') or + (c >= 'a' and c <= 'z') or + (c >= 'A' and c <= 'Z') or + c == '-' or c == '.' or + c == '_' or c == '~' + then + buf.add c + else buf.append "%{c.ascii.to_hex}" + end + + return buf.to_s + end + + # Decode `self` from percent (or URL) encoding to a clear string + # + # Replace invalid use of '%' with '?'. + # + # assert "aBc09-._~".from_percent_encoding == "aBc09-._~" + # assert "%25%28%29%3c%20%3e".from_percent_encoding == "%()< >" + # assert ".com%2fpost%3fe%3dasdf%26f%3d123".from_percent_encoding == ".com/post?e=asdf&f=123" + # assert "%25%28%29%3C%20%3E".from_percent_encoding == "%()< >" + # assert "incomplete %".from_percent_encoding == "incomplete ?" + # assert "invalid % usage".from_percent_encoding == "invalid ? usage" + fun from_percent_encoding: String + do + var buf = new FlatBuffer + + var i = 0 + while i < length do + var c = chars[i] + if c == '%' then + if i + 2 >= length then + # What follows % has been cut off + buf.add '?' + else + i += 1 + var hex_s = substring(i, 2) + if hex_s.is_hex then + var hex_i = hex_s.to_hex + buf.add hex_i.ascii + i += 1 + else + # What follows a % is not Hex + buf.add '?' + i -= 1 + end + end + else buf.add c + + i += 1 + end + + return buf.to_s + end + + # Escape the four characters `<`, `>`, `&`, and `"` with their html counterpart + # + # assert "a&b->\"x\"".html_escape == "a&b->"x"" + fun html_escape: SELFTYPE + do + var buf = new FlatBuffer + + for i in [0..length[ do + var c = chars[i] + if c == '&' then + buf.append "&" + else if c == '<' then + buf.append "<" + else if c == '>' then + buf.append ">" + else if c == '"' then + buf.append """ + else buf.add c + end + + return buf.to_s + end + + # Equality of text + # Two pieces of text are equals if thez have the same characters in the same order. + # + # assert "hello" == "hello" + # assert "hello" != "HELLO" + # assert "hello" == "hel"+"lo" + # + # Things that are not Text are not equal. + # + # assert "9" != '9' + # assert "9" != ['9'] + # assert "9" != 9 + # + # assert "9".chars.first == '9' # equality of Char + # assert "9".chars == ['9'] # equality of Sequence + # assert "9".to_i == 9 # equality of Int + redef fun ==(o) + do + if o == null then return false + if not o isa Text then return false + if self.is_same_instance(o) then return true + if self.length != o.length then return false + return self.chars == o.chars + end + + # Lexicographical comparaison + # + # assert "abc" < "xy" + # assert "ABC" < "abc" + redef fun <(other) + do + var self_chars = self.chars.iterator + var other_chars = other.chars.iterator + + while self_chars.is_ok and other_chars.is_ok do + if self_chars.item < other_chars.item then return true + if self_chars.item > other_chars.item then return false + self_chars.next + other_chars.next + end + + if self_chars.is_ok then + return false + else + return true + end + end + + # Escape string used in labels for graphviz + # + # assert ">><<".escape_to_dot == "\\>\\>\\<\\<" + fun escape_to_dot: String + do + return escape_more_to_c("|\{\}<>") + end + + # Flat representation of self + fun flatten: FlatText is abstract + + private var hash_cache: nullable Int = null + + redef fun hash + do + if hash_cache == null then + # djb2 hash algorithm + var h = 5381 + + for i in [0..length[ do + var char = chars[i] + h = h.lshift(5) + h + char.ascii + end + + hash_cache = h + end + return hash_cache.as(not null) + end + end -# Common subclass for String and Buffer -abstract class AbstractString +# All kinds of array-based text representations. +abstract class FlatText super Text - private var items: NativeString + # Underlying C-String (`char*`) + # + # Warning : Might be void in some subclasses, be sure to check + # if set before using it. + private var items: NativeString is noinit + + # Real items, used as cache for to_cstring is called + private var real_items: nullable NativeString = null - redef var length: Int + redef var length: Int = 0 init do end @@ -441,113 +767,244 @@ abstract class AbstractString i += 1 end end + + redef fun flatten do return self end # Abstract class for the SequenceRead compatible # views on String and Buffer objects -abstract class StringCharView +private abstract class StringCharView super SequenceRead[Char] type SELFTYPE: Text private var target: SELFTYPE - private init(tgt: SELFTYPE) - do - target = tgt - end - redef fun is_empty do return target.is_empty redef fun length do return target.length redef fun iterator: IndexedIterator[Char] do return self.iterator_from(0) - # Gets a new Iterator starting at position `pos` + redef fun reverse_iterator do return self.reverse_iterator_from(self.length - 1) +end + +# View on Buffer objects, extends Sequence +# for mutation operations +private abstract class BufferCharView + super StringCharView + super Sequence[Char] + + redef type SELFTYPE: Buffer + +end + +abstract class String + super Text + + redef type SELFTYPE: String + + redef fun to_s do return self + + # Concatenates `o` to `self` # - # Ex : - # var iter = "abcd".iterator_from(2) - # while iter.is_ok do - # printn iter.item - # iter.next - # end + # assert "hello" + "world" == "helloworld" + # assert "" + "hello" + "" == "hello" + fun +(o: Text): SELFTYPE is abstract + + # Concatenates self `i` times # - # Outputs : cd - fun iterator_from(pos: Int): IndexedIterator[Char] is abstract + # assert "abc" * 4 == "abcabcabcabc" + # assert "abc" * 1 == "abc" + # assert "abc" * 0 == "" + fun *(i: Int): SELFTYPE is abstract + + fun insert_at(s: String, pos: Int): SELFTYPE is abstract - # Gets an iterator starting at the end and going backwards + redef fun substrings: Iterator[String] is abstract + + # Returns a reversed version of self # - # Ex : - # var reviter = "now step live...".reverse_iterator - # while reviter.is_ok do - # printn reviter.item - # reviter.next - # end + # assert "hello".reversed == "olleh" + # assert "bob".reversed == "bob" + # assert "".reversed == "" + fun reversed: SELFTYPE is abstract + + # A upper case version of `self` # - # Outputs : ...evil pets won - fun reverse_iterator: IndexedIterator[Char] do return self.reverse_iterator_from(self.length - 1) + # assert "Hello World!".to_upper == "HELLO WORLD!" + fun to_upper: SELFTYPE is abstract - # Gets an iterator on the chars of self starting from `pos` + # A lower case version of `self` # - # Ex : - # var iter = "abcd".reverse_iterator_from(1) - # while iter.is_ok do - # printn iter.item - # iter.next - # end + # assert "Hello World!".to_lower == "hello world!" + fun to_lower : SELFTYPE is abstract + + # Takes a camel case `self` and converts it to snake case + # + # assert "randomMethodId".to_snake_case == "random_method_id" + # + # If `self` is upper, it is returned unchanged # - # Outputs : ba - fun reverse_iterator_from(pos: Int): IndexedIterator[Char] is abstract + # assert "RANDOM_METHOD_ID".to_snake_case == "RANDOM_METHOD_ID" + # + # If the identifier is prefixed by an underscore, the underscore is ignored + # + # assert "_privateField".to_snake_case == "_private_field" + fun to_snake_case: SELFTYPE + do + if self.is_upper then return self + + var new_str = new FlatBuffer.with_capacity(self.length) + var is_first_char = true + + for i in [0..length[ do + var char = chars[i] + if is_first_char then + new_str.add(char.to_lower) + is_first_char = false + else if char.is_upper then + new_str.add('_') + new_str.add(char.to_lower) + else + new_str.add(char) + end + end + + return new_str.to_s + end - redef fun has(c: Char): Bool - do - for i in self do - if i == c then return true + # Takes a snake case `self` and converts it to camel case + # + # assert "random_method_id".to_camel_case == "randomMethodId" + # + # If the identifier is prefixed by an underscore, the underscore is ignored + # + # assert "_private_field".to_camel_case == "_privateField" + # + # If `self` is upper, it is returned unchanged + # + # assert "RANDOM_ID".to_camel_case == "RANDOM_ID" + # + # If there are several consecutive underscores, they are considered as a single one + # + # assert "random__method_id".to_camel_case == "randomMethodId" + fun to_camel_case: SELFTYPE + do + if self.is_upper then return self + + var new_str = new FlatBuffer + var is_first_char = true + var follows_us = false + + for i in [0..length[ do + var char = chars[i] + if is_first_char then + new_str.add(char) + is_first_char = false + else if char == '_' then + follows_us = true + else if follows_us then + new_str.add(char.to_upper) + follows_us = false + else + new_str.add(char) + end end - return false + + return new_str.to_s end + # Returns a capitalized `self` + # + # Letters that follow a letter are lowercased + # Letters that follow a non-letter are upcased. + # + # SEE : `Char::is_letter` for the definition of letter. + # + # assert "jAVASCRIPT".capitalized == "Javascript" + # assert "i am root".capitalized == "I Am Root" + # assert "ab_c -ab0c ab\nc".capitalized == "Ab_C -Ab0C Ab\nC" + fun capitalized: SELFTYPE do + if length == 0 then return self + + var buf = new FlatBuffer.with_capacity(length) + + var curr = chars[0].to_upper + var prev = curr + buf[0] = curr + + for i in [1 .. length[ do + prev = curr + curr = self[i] + if prev.is_letter then + buf[i] = curr.to_lower + else + buf[i] = curr.to_upper + end + end + + return buf.to_s + end end -# View on Buffer objects, extends Sequence -# for mutation operations -abstract class BufferCharView - super StringCharView - super Sequence[Char] +private class FlatSubstringsIter + super Iterator[FlatText] - redef type SELFTYPE: Buffer + var tgt: nullable FlatText + + redef fun item do + assert is_ok + return tgt.as(not null) + end + redef fun is_ok do return tgt != null + + redef fun next do tgt = null end # Immutable strings of characters. -class String - super Comparable - super AbstractString - super StringCapable - - redef type OTHER: String +class FlatString + super FlatText + super String # Index in _items of the start of the string - private var index_from: Int + private var index_from: Int is noinit # Indes in _items of the last item of the string - private var index_to: Int + private var index_to: Int is noinit - redef var chars: StringCharView = new FlatStringCharView(self) + redef var chars: SequenceRead[Char] = new FlatStringCharView(self) - ################################################ - # AbstractString specific methods # - ################################################ - - redef fun [](index) do - assert index >= 0 + redef fun [](index) + do # Check that the index (+ index_from) is not larger than indexTo # In other terms, if the index is valid + assert index >= 0 assert (index + index_from) <= index_to return items[index + index_from] end - redef fun substring(from: Int, count: Int): String + ################################################ + # AbstractString specific methods # + ################################################ + + redef fun reversed + do + var native = new NativeString(self.length + 1) + var length = self.length + var items = self.items + var pos = 0 + var ipos = length-1 + while pos < length do + native[pos] = items[ipos] + pos += 1 + ipos -= 1 + end + return native.to_s_with_length(self.length) + end + + redef fun substring(from, count) do assert count >= 0 @@ -559,18 +1016,20 @@ class String var realFrom = index_from + from - if (realFrom + count) > index_to then return new String.with_infos(items, index_to - realFrom + 1, realFrom, index_to) + if (realFrom + count) > index_to then return new FlatString.with_infos(items, index_to - realFrom + 1, realFrom, index_to) - if count == 0 then return "" + if count == 0 then return empty var to = realFrom + count - 1 - return new String.with_infos(items, to - realFrom + 1, realFrom, to) + return new FlatString.with_infos(items, to - realFrom + 1, realFrom, to) end - redef fun to_upper: String + redef fun empty do return "".as(FlatString) + + redef fun to_upper do - var outstr = calloc_string(self.length + 1) + var outstr = new NativeString(self.length + 1) var out_index = 0 var myitems = self.items @@ -588,9 +1047,9 @@ class String return outstr.to_s_with_length(self.length) end - redef fun to_lower : String + redef fun to_lower do - var outstr = calloc_string(self.length + 1) + var outstr = new NativeString(self.length + 1) var out_index = 0 var myitems = self.items @@ -608,26 +1067,6 @@ class String return outstr.to_s_with_length(self.length) end - redef fun trim: String - do - if self.length == 0 then return self - # find position of the first non white space char (ascii < 32) from the start of the string - var start_pos = self.index_from - while items[start_pos].ascii <= 32 do - start_pos += 1 - if start_pos == index_to + 1 then return "" - end - # find position of the first non white space char from the end of the string - var end_pos = index_to - while items[end_pos].ascii <= 32 do - end_pos -= 1 - if end_pos == start_pos then return items[start_pos].to_s - end - start_pos -= index_from - end_pos -= index_from - return self.substring(start_pos, end_pos - start_pos + 1) - end - redef fun output do var i = self.index_from @@ -650,21 +1089,22 @@ class String index_to = to end - # Return a null terminated char * - fun to_cstring: NativeString + redef fun to_cstring: NativeString do - if index_from > 0 or index_to != items.cstring_length - 1 then - var newItems = calloc_string(length + 1) + if real_items != null then + return real_items.as(not null) + else + var newItems = new NativeString(length + 1) self.items.copy_to(newItems, length, index_from, 0) newItems[length] = '\0' + self.real_items = newItems return newItems end - return items end redef fun ==(other) do - if not other isa String then return false + if not other isa FlatString then return super if self.object_id == other.object_id then return true @@ -689,11 +1129,10 @@ class String return true end - # The comparison between two strings is done on a lexicographical basis - # - # assert ("aa" < "b") == true redef fun <(other) do + if not other isa FlatString then return super + if self.object_id == other.object_id then return false var my_curr_char : Char @@ -726,32 +1165,35 @@ class String return my_length < its_length end - # The concatenation of `self` with `s` - # - # assert "hello " + "world!" == "hello world!" - fun +(s: String): String + redef fun +(s) do var my_length = self.length var its_length = s.length var total_length = my_length + its_length - var target_string = calloc_string(my_length + its_length + 1) + var target_string = new NativeString(my_length + its_length + 1) self.items.copy_to(target_string, my_length, index_from, 0) - s.items.copy_to(target_string, its_length, s.index_from, my_length) + if s isa FlatString then + s.items.copy_to(target_string, its_length, s.index_from, my_length) + else if s isa FlatBuffer then + s.items.copy_to(target_string, its_length, 0, my_length) + else + var curr_pos = my_length + for i in [0..s.length[ do + var c = s.chars[i] + target_string[curr_pos] = c + curr_pos += 1 + end + end target_string[total_length] = '\0' return target_string.to_s_with_length(total_length) end - # `i` repetitions of `self` - # - # assert "abc"*3 == "abcabcabc" - # assert "abc"*1 == "abc" - # assert "abc"*0 == "" - fun *(i: Int): String + redef fun *(i) do assert i >= 0 @@ -761,7 +1203,7 @@ class String var my_items = self.items - var target_string = calloc_string((final_length) + 1) + var target_string = new NativeString(final_length + 1) target_string[final_length] = '\0' @@ -775,45 +1217,46 @@ class String return target_string.to_s_with_length(final_length) end - redef fun to_s do return self - redef fun hash do - # djb2 hash algorythm - var h = 5381 - var i = length - 1 + if hash_cache == null then + # djb2 hash algorithm + var h = 5381 + var i = index_from - var myitems = items - var strStart = index_from + var myitems = items - i += strStart + while i <= index_to do + h = h.lshift(5) + h + myitems[i].ascii + i += 1 + end - while i >= strStart do - h = (h * 32) + h + self.items[i].ascii - i -= 1 + hash_cache = h end - return h + return hash_cache.as(not null) end + + redef fun substrings do return new FlatSubstringsIter(self) end private class FlatStringReverseIterator super IndexedIterator[Char] - var target: String + var target: FlatString var target_items: NativeString var curr_pos: Int - init with_pos(tgt: String, pos: Int) + init with_pos(tgt: FlatString, pos: Int) do target = tgt target_items = tgt.items curr_pos = pos + tgt.index_from end - redef fun is_ok do return curr_pos >= 0 + redef fun is_ok do return curr_pos >= target.index_from redef fun item do return target_items[curr_pos] @@ -826,13 +1269,13 @@ end private class FlatStringIterator super IndexedIterator[Char] - var target: String + var target: FlatString var target_items: NativeString var curr_pos: Int - init with_pos(tgt: String, pos: Int) + init with_pos(tgt: FlatString, pos: Int) do target = tgt target_items = tgt.items @@ -852,13 +1295,14 @@ end private class FlatStringCharView super StringCharView - redef type SELFTYPE: String + redef type SELFTYPE: FlatString redef fun [](index) do # Check that the index (+ index_from) is not larger than indexTo # In other terms, if the index is valid assert index >= 0 + var target = self.target assert (index + target.index_from) <= target.index_to return target.items[index + target.index_from] end @@ -869,103 +1313,239 @@ private class FlatStringCharView end -# Mutable strings of characters. -class Buffer - super AbstractString - super Comparable - super StringCapable +abstract class Buffer + super Text - redef type OTHER: String + redef type SELFTYPE: Buffer - redef var chars: BufferCharView = new FlatBufferCharView(self) + # Specific implementations MUST set this to `true` in order to invalidate caches + protected var is_dirty = true - var capacity: Int + # Copy-On-Write flag + # + # If the `Buffer` was to_s'd, the next in-place altering + # operation will cause the current `Buffer` to be re-allocated. + # + # The flag will then be set at `false`. + protected var written = false # Modifies the char contained at pos `index` # # DEPRECATED : Use self.chars.[]= instead - fun []=(index: Int, item: Char) + fun []=(index: Int, item: Char) is abstract + + # Adds a char `c` at the end of self + # + # DEPRECATED : Use self.chars.add instead + fun add(c: Char) is abstract + + # Clears the buffer + # + # var b = new FlatBuffer + # b.append "hello" + # assert not b.is_empty + # b.clear + # assert b.is_empty + fun clear is abstract + + # Enlarges the subsequent array containing the chars of self + fun enlarge(cap: Int) is abstract + + # Adds the content of text `s` at the end of self + # + # var b = new FlatBuffer + # b.append "hello" + # b.append "world" + # assert b == "helloworld" + fun append(s: Text) is abstract + + # `self` is appended in such a way that `self` is repeated `r` times + # + # var b = new FlatBuffer + # b.append "hello" + # b.times 3 + # assert b == "hellohellohello" + fun times(r: Int) is abstract + + # Reverses itself in-place + # + # var b = new FlatBuffer + # b.append("hello") + # b.reverse + # assert b == "olleh" + fun reverse is abstract + + # Changes each lower-case char in `self` by its upper-case variant + # + # var b = new FlatBuffer + # b.append("Hello World!") + # b.upper + # assert b == "HELLO WORLD!" + fun upper is abstract + + # Changes each upper-case char in `self` by its lower-case variant + # + # var b = new FlatBuffer + # b.append("Hello World!") + # b.lower + # assert b == "hello world!" + fun lower is abstract + + # Capitalizes each word in `self` + # + # Letters that follow a letter are lowercased + # Letters that follow a non-letter are upcased. + # + # SEE: `Char::is_letter` for the definition of a letter. + # + # var b = new FlatBuffer.from("jAVAsCriPt")" + # b.capitalize + # assert b == "Javascript" + # b = new FlatBuffer.from("i am root") + # b.capitalize + # assert b == "I Am Root" + # b = new FlatBuffer.from("ab_c -ab0c ab\nc") + # b.capitalize + # assert b == "Ab_C -Ab0C Ab\nC" + fun capitalize do + if length == 0 then return + var c = self[0].to_upper + self[0] = c + var prev: Char = c + for i in [1 .. length[ do + prev = c + c = self[i] + if prev.is_letter then + self[i] = c.to_lower + else + self[i] = c.to_upper + end + end + end + + redef fun hash do + if is_dirty then hash_cache = null + return super + end + + # In Buffers, the internal sequence of character is mutable + # Thus, `chars` can be used to modify the buffer. + redef fun chars: Sequence[Char] is abstract +end + +# Mutable strings of characters. +class FlatBuffer + super FlatText + super Buffer + + redef type SELFTYPE: FlatBuffer + + redef var chars: Sequence[Char] = new FlatBufferCharView(self) + + private var capacity: Int = 0 + + redef fun substrings do return new FlatSubstringsIter(self) + + # Re-copies the `NativeString` into a new one and sets it as the new `Buffer` + # + # This happens when an operation modifies the current `Buffer` and + # the Copy-On-Write flag `written` is set at true. + private fun reset do + var nns = new NativeString(capacity) + items.copy_to(nns, length, 0, 0) + items = nns + written = false + end + + redef fun [](index) + do + assert index >= 0 + assert index < length + return items[index] + end + + redef fun []=(index, item) + do + is_dirty = true if index == length then add(item) return end + if written then reset assert index >= 0 and index < length items[index] = item end - # Adds a char `c` at the end of self - # - # DEPRECATED : Use self.chars.add instead - fun add(c: Char) + redef fun add(c) do + is_dirty = true if capacity <= length then enlarge(length + 5) items[length] = c length += 1 end - # Clears the buffer - fun clear do length = 0 + redef fun clear do + is_dirty = true + if written then reset + length = 0 + end - # Enlarges the subsequent array containing the chars of self - fun enlarge(cap: Int) + redef fun empty do return new FlatBuffer + + redef fun enlarge(cap) do var c = capacity if cap <= c then return while c <= cap do c = c * 2 + 2 - var a = calloc_string(c+1) - items.copy_to(a, length, 0, 0) + # The COW flag can be set at false here, since + # it does a copy of the current `Buffer` + written = false + var a = new NativeString(c+1) + if length > 0 then items.copy_to(a, length, 0, 0) items = a capacity = c - items.copy_to(a, length, 0, 0) end redef fun to_s: String do - var l = length - var a = calloc_string(l+1) - items.copy_to(a, l, 0, 0) - - # Ensure the afterlast byte is '\0' to nul-terminated char * - a[length] = '\0' - - return a.to_s_with_length(length) + written = true + if length == 0 then items = new NativeString(1) + return new FlatString.with_infos(items, length, 0, length - 1) end - redef fun <(s) + redef fun to_cstring do - var i = 0 - var l1 = length - var l2 = s.length - while i < l1 and i < l2 do - var c1 = self.chars[i].ascii - var c2 = s.chars[i].ascii - if c1 < c2 then - return true - else if c2 < c1 then - return false - end - i += 1 - end - if l1 < l2 then - return true - else - return false + if is_dirty then + var new_native = new NativeString(length + 1) + new_native[length] = '\0' + if length > 0 then items.copy_to(new_native, length, 0, 0) + real_items = new_native + is_dirty = false end + return real_items.as(not null) end # Create a new empty string. - init - do - with_capacity(5) - end + init do end - init from(s: String) + init from(s: Text) do capacity = s.length + 1 length = s.length - items = calloc_string(capacity) - s.items.copy_to(items, length, s.index_from, 0) + items = new NativeString(capacity) + if s isa FlatString then + s.items.copy_to(items, length, s.index_from, 0) + else if s isa FlatBuffer then + s.items.copy_to(items, length, 0, 0) + else + var curr_pos = 0 + for i in [0..s.length[ do + var c = s.chars[i] + items[curr_pos] = c + curr_pos += 1 + end + end end # Create a new empty string with a given capacity. @@ -973,33 +1553,30 @@ class Buffer do assert cap >= 0 # _items = new NativeString.calloc(cap) - items = calloc_string(cap+1) + items = new NativeString(cap+1) capacity = cap length = 0 end - # Adds the content of string `s` at the end of self - fun append(s: String) + redef fun append(s) do + if s.is_empty then return + is_dirty = true var sl = s.length if capacity < length + sl then enlarge(length + sl) - s.items.copy_to(items, sl, s.index_from, length) - length += sl - end - - redef fun ==(o) - do - if not o isa Buffer then return false - var l = length - if o.length != l then return false - var i = 0 - var it = items - var oit = o.items - while i < l do - if it[i] != oit[i] then return false - i += 1 + if s isa FlatString then + s.items.copy_to(items, sl, s.index_from, length) + else if s isa FlatBuffer then + s.items.copy_to(items, sl, 0, length) + else + var curr_pos = self.length + for i in [0..s.length[ do + var c = s.chars[i] + items[curr_pos] = c + curr_pos += 1 + end end - return true + length += sl end # Copies the content of self in `dest` @@ -1019,14 +1596,59 @@ class Buffer if from < 0 then from = 0 if count > length then count = length if from < count then - var r = new Buffer.with_capacity(count - from) + var r = new FlatBuffer.with_capacity(count - from) while from < count do r.chars.push(items[from]) from += 1 end - return r.to_s + return r else - return "" + return new FlatBuffer + end + end + + redef fun reverse + do + written = false + var ns = new NativeString(capacity) + var si = length - 1 + var ni = 0 + var it = items + while si >= 0 do + ns[ni] = it[si] + ni += 1 + si -= 1 + end + items = ns + end + + redef fun times(repeats) + do + var x = new FlatString.with_infos(items, length, 0, length - 1) + for i in [1..repeats[ do + append(x) + end + end + + redef fun upper + do + if written then reset + var it = items + var id = length - 1 + while id >= 0 do + it[id] = it[id].to_upper + id -= 1 + end + end + + redef fun lower + do + if written then reset + var it = items + var id = length - 1 + while id >= 0 do + it[id] = it[id].to_lower + id -= 1 end end end @@ -1034,16 +1656,16 @@ end private class FlatBufferReverseIterator super IndexedIterator[Char] - var target: Buffer + var target: FlatBuffer var target_items: NativeString var curr_pos: Int - init with_pos(tgt: Buffer, pos: Int) + init with_pos(tgt: FlatBuffer, pos: Int) do target = tgt - target_items = tgt.items + if tgt.length > 0 then target_items = tgt.items curr_pos = pos end @@ -1059,9 +1681,8 @@ end private class FlatBufferCharView super BufferCharView - super StringCapable - redef type SELFTYPE: Buffer + redef type SELFTYPE: FlatBuffer redef fun [](index) do return target.items[index] @@ -1106,16 +1727,16 @@ end private class FlatBufferIterator super IndexedIterator[Char] - var target: Buffer + var target: FlatBuffer var target_items: NativeString var curr_pos: Int - init with_pos(tgt: Buffer, pos: Int) + init with_pos(tgt: FlatBuffer, pos: Int) do target = tgt - target_items = tgt.items + if tgt.length > 0 then target_items = tgt.items curr_pos = pos end @@ -1158,11 +1779,6 @@ redef class Object do return "{class_name}:#{object_id.to_hex}" end - - protected fun args: Sequence[String] - do - return sys.args - end end redef class Bool @@ -1179,9 +1795,18 @@ redef class Bool end redef class Int + + # Wrapper of strerror C function + private fun strerror_ext: NativeString is extern `{ + return strerror(recv); + `} + + # Returns a string describing error number + fun strerror: String do return strerror_ext.to_s + # Fill `s` with the digits in base `base` of `self` (and with the '-' sign if 'signed' and negative). # assume < to_c max const of char - fun fill_buffer(s: Buffer, base: Int, signed: Bool) + private fun fill_buffer(s: Buffer, base: Int, signed: Bool) do var n: Int # Sign @@ -1204,32 +1829,39 @@ redef class Int end # C function to convert an nit Int to a NativeString (char*) - private fun native_int_to_s(len: Int): NativeString is extern "native_int_to_s" + private fun native_int_to_s: NativeString is extern "native_int_to_s" # return displayable int in base 10 and signed # # assert 1.to_s == "1" # assert (-123).to_s == "-123" redef fun to_s do - var len = digit_count(10) - return native_int_to_s(len).to_s_with_length(len) + return native_int_to_s.to_s end - # return displayable int in hexadecimal (unsigned (not now)) + # return displayable int in hexadecimal + # + # assert 1.to_hex == "1" + # assert (-255).to_hex == "-ff" fun to_hex: String do return to_base(16,false) # return displayable int in base base and signed fun to_base(base: Int, signed: Bool): String do var l = digit_count(base) - var s = new Buffer.from(" " * l) + var s = new FlatBuffer.from(" " * l) fill_buffer(s, base, signed) return s.to_s end end redef class Float - # Pretty print self, print needoed decimals up to a max of 3. + # Pretty representation of `self`, with decimals as needed from 1 to a maximum of 3 + # + # assert 12.34.to_s == "12.34" + # assert (-0120.030).to_s == "-120.03" + # + # see `to_precision` for a custom precision. redef fun to_s do var str = to_precision( 3 ) if is_inf != 0 or is_nan then return str @@ -1248,8 +1880,15 @@ redef class Float return str end - # `self` representation with `nb` digits after the '.'. - fun to_precision(nb: Int): String + # `String` representation of `self` with the given number of `decimals` + # + # assert 12.345.to_precision(0) == "12" + # assert 12.345.to_precision(3) == "12.345" + # assert (-12.345).to_precision(3) == "-12.345" + # assert (-0.123).to_precision(3) == "-0.123" + # assert 0.999.to_precision(2) == "1.00" + # assert 0.999.to_precision(4) == "0.9990" + fun to_precision(decimals: Int): String do if is_nan then return "nan" @@ -1260,27 +1899,42 @@ redef class Float return "-inf" end - if nb == 0 then return self.to_i.to_s + if decimals == 0 then return self.to_i.to_s var f = self - for i in [0..nb[ do f = f * 10.0 + for i in [0..decimals[ do f = f * 10.0 if self > 0.0 then f = f + 0.5 else f = f - 0.5 end var i = f.to_i - if i == 0 then return "0.0" - var s = i.to_s + if i == 0 then return "0." + "0"*decimals + + # Prepare both parts of the float, before and after the "." + var s = i.abs.to_s var sl = s.length - if sl > nb then - var p1 = s.substring(0, s.length-nb) - var p2 = s.substring(s.length-nb, nb) - return p1 + "." + p2 + var p1 + var p2 + if sl > decimals then + # Has something before the "." + p1 = s.substring(0, sl-decimals) + p2 = s.substring(sl-decimals, decimals) else - return "0." + ("0"*(nb-sl)) + s + p1 = "0" + p2 = "0"*(decimals-sl) + s end + + if i < 0 then p1 = "-" + p1 + + return p1 + "." + p2 end + # `self` representation with `nb` digits after the '.'. + # + # assert 12.345.to_precision_native(1) == "12.3" + # assert 12.345.to_precision_native(2) == "12.35" + # assert 12.345.to_precision_native(3) == "12.345" + # assert 12.345.to_precision_native(4) == "12.3450" fun to_precision_native(nb: Int): String import NativeString.to_s `{ int size; char *str; @@ -1297,33 +1951,43 @@ redef class Char # assert 'x'.to_s == "x" redef fun to_s do - var s = new Buffer.with_capacity(1) + var s = new FlatBuffer.with_capacity(1) s.chars[0] = self return s.to_s end # Returns true if the char is a numerical digit + # + # assert '0'.is_numeric + # assert '9'.is_numeric + # assert not 'a'.is_numeric + # assert not '?'.is_numeric fun is_numeric: Bool do - if self >= '0' and self <= '9' - then - return true - end - return false + return self >= '0' and self <= '9' end # Returns true if the char is an alpha digit + # + # assert 'a'.is_alpha + # assert 'Z'.is_alpha + # assert not '0'.is_alpha + # assert not '?'.is_alpha fun is_alpha: Bool do - if (self >= 'a' and self <= 'z') or (self >= 'A' and self <= 'Z') then return true - return false + return (self >= 'a' and self <= 'z') or (self >= 'A' and self <= 'Z') end # Returns true if the char is an alpha or a numeric digit + # + # assert 'a'.is_alphanumeric + # assert 'Z'.is_alphanumeric + # assert '0'.is_alphanumeric + # assert '9'.is_alphanumeric + # assert not '?'.is_alphanumeric fun is_alphanumeric: Bool do - if self.is_numeric or self.is_alpha then return true - return false + return self.is_numeric or self.is_alpha end end @@ -1331,7 +1995,7 @@ redef class Collection[E] # Concatenate elements. redef fun to_s do - var s = new Buffer + var s = new FlatBuffer for e in self do if e != null then s.append(e.to_s) return s.to_s end @@ -1340,11 +2004,11 @@ redef class Collection[E] # # assert [1, 2, 3].join(":") == "1:2:3" # assert [1..3].join(":") == "1:2:3" - fun join(sep: String): String + fun join(sep: Text): String do if is_empty then return "" - var s = new Buffer # Result + var s = new FlatBuffer # Result # Concat first item var i = iterator @@ -1364,18 +2028,51 @@ redef class Collection[E] end redef class Array[E] + # Fast implementation redef fun to_s do - var s = new Buffer - var i = 0 var l = length + if l == 0 then return "" + if l == 1 then if self[0] == null then return "" else return self[0].to_s + var its = _items + var na = new NativeArray[String](l) + var i = 0 + var sl = 0 + var mypos = 0 while i < l do - var e = self[i] - if e != null then s.append(e.to_s) + var itsi = its[i] + if itsi == null then + i += 1 + continue + end + var tmp = itsi.to_s + sl += tmp.length + na[mypos] = tmp i += 1 + mypos += 1 end - return s.to_s + var ns = new NativeString(sl + 1) + ns[sl] = '\0' + i = 0 + var off = 0 + while i < mypos do + var tmp = na[i] + var tpl = tmp.length + if tmp isa FlatString then + tmp.items.copy_to(ns, tpl, tmp.index_from, off) + off += tpl + else + for j in tmp.substrings do + var s = j.as(FlatString) + var slen = s.length + s.items.copy_to(ns, slen, s.index_from, off) + off += slen + end + end + i += 1 + end + return ns.to_s_with_length(sl) end end @@ -1392,7 +2089,7 @@ redef class Map[K,V] do if is_empty then return "" - var s = new Buffer # Result + var s = new FlatBuffer # Result # Concat first item var i = iterator @@ -1418,9 +2115,9 @@ end ############################################################################### # Native strings are simple C char * -class NativeString - super StringCapable - +extern class NativeString `{ char* `} + # Creates a new NativeString with a capacity of `length` + new(length: Int) is intern fun [](index: Int): Char is intern fun []=(index: Int, item: Char) is intern fun copy_to(dest: NativeString, length: Int, from: Int, to: Int) is intern @@ -1440,31 +2137,30 @@ class NativeString return to_s_with_length(cstring_length) end - fun to_s_with_length(length: Int): String + fun to_s_with_length(length: Int): FlatString do assert length >= 0 - return new String.with_infos(self, length, 0, length - 1) + var str = new FlatString.with_infos(self, length, 0, length - 1) + return str end - fun to_s_with_copy: String + fun to_s_with_copy: FlatString do var length = cstring_length - var new_self = calloc_string(length + 1) + var new_self = new NativeString(length + 1) copy_to(new_self, length, 0, 0) - return new String.with_infos(new_self, length, 0, length - 1) + var str = new FlatString.with_infos(new_self, length, 0, length - 1) + new_self[length] = '\0' + str.real_items = new_self + return str end - -end - -# StringCapable objects can create native strings -interface StringCapable - protected fun calloc_string(size: Int): NativeString is intern end redef class Sys - var _args_cache: nullable Sequence[String] + private var args_cache: nullable Sequence[String] - redef fun args: Sequence[String] + # The arguments of the program as given by the OS + fun program_args: Sequence[String] do if _args_cache == null then init_args return _args_cache.as(not null) @@ -1476,7 +2172,7 @@ redef class Sys return native_argv(0).to_s end - # Initialize `args` with the contents of `native_argc` and `native_argv`. + # Initialize `program_args` with the contents of `native_argc` and `native_argv`. private fun init_args do var argc = native_argc @@ -1496,3 +2192,54 @@ redef class Sys private fun native_argv(i: Int): NativeString is intern end +# Comparator that efficienlty use `to_s` to compare things +# +# The comparaison call `to_s` on object and use the result to order things. +# +# var a = [1, 2, 3, 10, 20] +# (new CachedAlphaComparator).sort(a) +# assert a == [1, 10, 2, 20, 3] +# +# Internally the result of `to_s` is cached in a HashMap to counter +# uneficient implementation of `to_s`. +# +# Note: it caching is not usefull, see `alpha_comparator` +class CachedAlphaComparator + super Comparator + redef type COMPARED: Object + + private var cache = new HashMap[Object, String] + + private fun do_to_s(a: Object): String do + if cache.has_key(a) then return cache[a] + var res = a.to_s + cache[a] = res + return res + end + + redef fun compare(a, b) do + return do_to_s(a) <=> do_to_s(b) + end +end + +# see `alpha_comparator` +private class AlphaComparator + super Comparator + redef fun compare(a, b) do return a.to_s <=> b.to_s +end + +# Stateless comparator that naively use `to_s` to compare things. +# +# Note: the result of `to_s` is not cached, thus can be invoked a lot +# on a single instace. See `CachedAlphaComparator` as an alternative. +# +# var a = [1, 2, 3, 10, 20] +# alpha_comparator.sort(a) +# assert a == [1, 10, 2, 20, 3] +fun alpha_comparator: Comparator do return once new AlphaComparator + +# The arguments of the program as given by the OS +fun args: Sequence[String] +do + return sys.program_args +end