ceph/src/boost/tools/build/src/util/string.jam

   1 # Copyright 2002 Dave Abrahams
   2 # Copyright 2002, 2003 Rene Rivera
   3 # Distributed under the Boost Software License, Version 1.0.
   4 # (See accompanying file LICENSE.txt or https://www.bfgroup.xyz/b2/LICENSE.txt)
   5
   6 import regex ;
   7
   8
   9 # Characters considered whitespace, as a list.
  10 .whitespace-chars = " " "       " "
  11 " ;
  12
  13 # Characters considered whitespace, as a single string.
  14 .whitespace = $(.whitespace-chars:J="") ;
  15
  16
  17 # Returns the canonical set of whitespace characters, as a list.
  18 #
  19 rule whitespace-chars ( )
  20 {
  21     return $(.whitespace-chars) ;
  22 }
  23
  24
  25 # Returns the canonical set of whitespace characters, as a single string.
  26 #
  27 rule whitespace ( )
  28 {
  29     return $(.whitespace) ;
  30 }
  31
  32
  33 # Splits the given string into a list of strings composed of each character of
  34 # the string in sequence.
  35 #
  36 rule chars (
  37     string  # The string to split.
  38     )
  39 {
  40     local result ;
  41     while $(string)
  42     {
  43         local s = [ MATCH (.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.*) : $(string) ] ;
  44         string = $(s[9]) ;
  45         result += $(s[1-8]) ;
  46     }
  47
  48     # Trim off empty strings.
  49     while $(result[1]) && ! $(result[-1])
  50     {
  51         result = $(result[1--2]) ;
  52     }
  53
  54     return $(result) ;
  55 }
  56
  57
  58 # Apply a set of standard transformations to string to produce an abbreviation
  59 # no more than 5 characters long.
  60 #
  61 rule abbreviate ( string )
  62 {
  63     local r = $(.abbreviated-$(string)) ;
  64     if $(r)
  65     {
  66         return $(r) ;
  67     }
  68     # Anything less than 4 characters gets no abbreviation.
  69     else if ! [ MATCH (....) : $(string) ]
  70     {
  71         .abbreviated-$(string) = $(string) ;
  72         return $(string) ;
  73     }
  74     else
  75     {
  76         # Separate the initial letter in case it's a vowel.
  77         local s1 = [ MATCH ^(.)(.*) : $(string) ] ;
  78
  79         # Drop trailing "ing".
  80         local s2 = [ MATCH ^(.*)ing$ : $(s1[2]) ] ;
  81         s2 ?= $(s1[2]) ;
  82
  83         # Reduce all doubled characters to one.
  84         local last = "" ;
  85         for local c in [ chars $(s2) ]
  86         {
  87             if $(c) != $(last)
  88             {
  89                 r += $(c) ;
  90                 last = $(c) ;
  91             }
  92         }
  93         s2 = $(r:J="") ;
  94
  95         # Chop all vowels out of the remainder.
  96         s2 = [ regex.replace $(s2) "[AEIOUaeiou]" "" ] ;
  97
  98         # Shorten remaining consonants to 4 characters.
  99         s2 = [ MATCH ^(.?.?.?.?) : $(s2) ] ;
 100
 101         # Glue the initial character back on to the front.
 102         s2 = $(s1[1])$(s2) ;
 103
 104         .abbreviated-$(string) = $(s2) ;
 105         return $(s2) ;
 106     }
 107 }
 108
 109
 110 # Concatenates the given strings, inserting the given separator between each
 111 # string.
 112 #
 113 rule join (
 114     strings *  # The strings to join.
 115     : separator ?  # The optional separator.
 116     )
 117 {
 118     separator ?= "" ;
 119     return $(strings:J=$(separator)) ;
 120 }
 121
 122
 123 # Split a string into whitespace separated words.
 124 #
 125 rule words (
 126     string  # The string to split.
 127     : whitespace *  # Optional, characters to consider as whitespace.
 128     )
 129 {
 130     whitespace = $(whitespace:J="") ;
 131     whitespace ?= $(.whitespace) ;
 132     local w = ;
 133     while $(string)
 134     {
 135         string = [ MATCH "^[$(whitespace)]*([^$(whitespace)]*)(.*)" : $(string) ] ;
 136         if $(string[1]) && $(string[1]) != ""
 137         {
 138             w += $(string[1]) ;
 139         }
 140         string = $(string[2]) ;
 141     }
 142     return $(w) ;
 143 }
 144
 145
 146 # Check that the given string is composed entirely of whitespace.
 147 #
 148 rule is-whitespace (
 149     string ?  # The string to test.
 150     )
 151 {
 152     if ! $(string) { return true ; }
 153     else if $(string) = "" { return true ; }
 154     else if [ MATCH "^([$(.whitespace)]+)$" : $(string) ] { return true ; }
 155     else { return ; }
 156 }
 157
 158 rule __test__ ( )
 159 {
 160     import assert ;
 161     assert.result a b c : chars abc ;
 162
 163     assert.result rntm : abbreviate runtime ;
 164     assert.result ovrld : abbreviate overload ;
 165     assert.result dbg : abbreviate debugging ;
 166     assert.result async : abbreviate asynchronous ;
 167     assert.result pop : abbreviate pop ;
 168     assert.result aaa : abbreviate aaa ;
 169     assert.result qck : abbreviate quack ;
 170     assert.result sttc : abbreviate static ;
 171
 172     # Check boundary cases.
 173     assert.result a : chars a ;
 174     assert.result : chars "" ;
 175     assert.result a b c d e f g h : chars abcdefgh ;
 176     assert.result a b c d e f g h i : chars abcdefghi ;
 177     assert.result a b c d e f g h i j : chars abcdefghij ;
 178     assert.result a b c d e f g h i j k : chars abcdefghijk ;
 179
 180     assert.result a//b/c/d : join a "" b c d : / ;
 181     assert.result abcd : join  a "" b c d ;
 182
 183     assert.result a b c : words "a b    c" ;
 184
 185     assert.true is-whitespace "         " ;
 186     assert.false is-whitespace "  a b c " ;
 187     assert.true is-whitespace "" ;
 188     assert.true is-whitespace ;
 189 }