1 files changed, 189 insertions, 0 deletions
diff --git a/tools/build/src/util/string.jam b/tools/build/src/util/string.jam
new file mode 100644
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+++ b/tools/build/src/util/string.jam
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+# Copyright 2002 Dave Abrahams
+# Copyright 2002, 2003 Rene Rivera
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
+
+import regex ;
+
+
+# Characters considered whitespace, as a list.
+.whitespace-chars = " " "	" "
+" ;
+
+# Characters considered whitespace, as a single string.
+.whitespace = $(.whitespace-chars:J="") ;
+
+
+# Returns the canonical set of whitespace characters, as a list.
+#
+rule whitespace-chars ( )
+{
+    return $(.whitespace-chars) ;
+}
+
+
+# Returns the canonical set of whitespace characters, as a single string.
+#
+rule whitespace ( )
+{
+    return $(.whitespace) ;
+}
+
+
+# Splits the given string into a list of strings composed of each character of
+# the string in sequence.
+#
+rule chars (
+    string  # The string to split.
+    )
+{
+    local result ;
+    while $(string)
+    {
+        local s = [ MATCH (.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.*) : $(string) ] ;
+        string = $(s[9]) ;
+        result += $(s[1-8]) ;
+    }
+
+    # Trim off empty strings.
+    while $(result[1]) && ! $(result[-1])
+    {
+        result = $(result[1--2]) ;
+    }
+
+    return $(result) ;
+}
+
+
+# Apply a set of standard transformations to string to produce an abbreviation
+# no more than 5 characters long.
+#
+rule abbreviate ( string )
+{
+    local r = $(.abbreviated-$(string)) ;
+    if $(r)
+    {
+        return $(r) ;
+    }
+    # Anything less than 4 characters gets no abbreviation.
+    else if ! [ MATCH (....) : $(string) ]
+    {
+        .abbreviated-$(string) = $(string) ;
+        return $(string) ;
+    }
+    else
+    {
+        # Separate the initial letter in case it's a vowel.
+        local s1 = [ MATCH ^(.)(.*) : $(string) ] ;
+
+        # Drop trailing "ing".
+        local s2 = [ MATCH ^(.*)ing$ : $(s1[2]) ] ;
+        s2 ?= $(s1[2]) ;
+
+        # Reduce all doubled characters to one.
+        local last = "" ;
+        for local c in [ chars $(s2) ]
+        {
+            if $(c) != $(last)
+            {
+                r += $(c) ;
+                last = $(c) ;
+            }
+        }
+        s2 = $(r:J="") ;
+
+        # Chop all vowels out of the remainder.
+        s2 = [ regex.replace $(s2) [AEIOUaeiou] "" ] ;
+
+        # Shorten remaining consonants to 4 characters.
+        s2 = [ MATCH ^(.?.?.?.?) : $(s2) ] ;
+
+        # Glue the initial character back on to the front.
+        s2 = $(s1[1])$(s2) ;
+
+        .abbreviated-$(string) = $(s2) ;
+        return $(s2) ;
+    }
+}
+
+
+# Concatenates the given strings, inserting the given separator between each
+# string.
+#
+rule join (
+    strings *  # The strings to join.
+    : separator ?  # The optional separator.
+    )
+{
+    separator ?= "" ;
+    return $(strings:J=$(separator)) ;
+}
+
+
+# Split a string into whitespace separated words.
+#
+rule words (
+    string  # The string to split.
+    : whitespace *  # Optional, characters to consider as whitespace.
+    )
+{
+    whitespace = $(whitespace:J="") ;
+    whitespace ?= $(.whitespace) ;
+    local w = ;
+    while $(string)
+    {
+        string = [ MATCH "^[$(whitespace)]*([^$(whitespace)]*)(.*)" : $(string) ] ;
+        if $(string[1]) && $(string[1]) != ""
+        {
+            w += $(string[1]) ;
+        }
+        string = $(string[2]) ;
+    }
+    return $(w) ;
+}
+
+
+# Check that the given string is composed entirely of whitespace.
+#
+rule is-whitespace (
+    string ?  # The string to test.
+    )
+{
+    if ! $(string) { return true ; }
+    else if $(string) = "" { return true ; }
+    else if [ MATCH "^([$(.whitespace)]+)$" : $(string) ] { return true ; }
+    else { return ; }
+}
+
+rule __test__ ( )
+{
+    import assert ;
+    assert.result a b c : chars abc ;
+
+    assert.result rntm : abbreviate runtime ;
+    assert.result ovrld : abbreviate overload ;
+    assert.result dbg : abbreviate debugging ;
+    assert.result async : abbreviate asynchronous ;
+    assert.result pop : abbreviate pop ;
+    assert.result aaa : abbreviate aaa ;
+    assert.result qck : abbreviate quack ;
+    assert.result sttc : abbreviate static ;
+
+    # Check boundary cases.
+    assert.result a : chars a ;
+    assert.result : chars "" ;
+    assert.result a b c d e f g h : chars abcdefgh ;
+    assert.result a b c d e f g h i : chars abcdefghi ;
+    assert.result a b c d e f g h i j : chars abcdefghij ;
+    assert.result a b c d e f g h i j k : chars abcdefghijk ;
+
+    assert.result a//b/c/d : join a "" b c d : / ;
+    assert.result abcd : join  a "" b c d ;
+
+    assert.result a b c : words "a b	c" ;
+
+    assert.true is-whitespace "     	" ;
+    assert.false is-whitespace "  a b c	" ;
+    assert.true is-whitespace "" ;
+    assert.true is-whitespace ;
+}