cowboy_bstr.erl (3983B)
1 %% Copyright (c) 2011-2017, Loïc Hoguin <essen@ninenines.eu> 2 %% 3 %% Permission to use, copy, modify, and/or distribute this software for any 4 %% purpose with or without fee is hereby granted, provided that the above 5 %% copyright notice and this permission notice appear in all copies. 6 %% 7 %% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 %% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 %% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 10 %% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 %% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 12 %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 13 %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 14 15 -module(cowboy_bstr). 16 17 %% Binary strings. 18 -export([capitalize_token/1]). 19 -export([to_lower/1]). 20 -export([to_upper/1]). 21 22 %% Characters. 23 -export([char_to_lower/1]). 24 -export([char_to_upper/1]). 25 26 %% The first letter and all letters after a dash are capitalized. 27 %% This is the form seen for header names in the HTTP/1.1 RFC and 28 %% others. Note that using this form isn't required, as header names 29 %% are case insensitive, and it is only provided for use with eventual 30 %% badly implemented clients. 31 -spec capitalize_token(B) -> B when B::binary(). 32 capitalize_token(B) -> 33 capitalize_token(B, true, <<>>). 34 capitalize_token(<<>>, _, Acc) -> 35 Acc; 36 capitalize_token(<< $-, Rest/bits >>, _, Acc) -> 37 capitalize_token(Rest, true, << Acc/binary, $- >>); 38 capitalize_token(<< C, Rest/bits >>, true, Acc) -> 39 capitalize_token(Rest, false, << Acc/binary, (char_to_upper(C)) >>); 40 capitalize_token(<< C, Rest/bits >>, false, Acc) -> 41 capitalize_token(Rest, false, << Acc/binary, (char_to_lower(C)) >>). 42 43 -spec to_lower(B) -> B when B::binary(). 44 to_lower(B) -> 45 << << (char_to_lower(C)) >> || << C >> <= B >>. 46 47 -spec to_upper(B) -> B when B::binary(). 48 to_upper(B) -> 49 << << (char_to_upper(C)) >> || << C >> <= B >>. 50 51 -spec char_to_lower(char()) -> char(). 52 char_to_lower($A) -> $a; 53 char_to_lower($B) -> $b; 54 char_to_lower($C) -> $c; 55 char_to_lower($D) -> $d; 56 char_to_lower($E) -> $e; 57 char_to_lower($F) -> $f; 58 char_to_lower($G) -> $g; 59 char_to_lower($H) -> $h; 60 char_to_lower($I) -> $i; 61 char_to_lower($J) -> $j; 62 char_to_lower($K) -> $k; 63 char_to_lower($L) -> $l; 64 char_to_lower($M) -> $m; 65 char_to_lower($N) -> $n; 66 char_to_lower($O) -> $o; 67 char_to_lower($P) -> $p; 68 char_to_lower($Q) -> $q; 69 char_to_lower($R) -> $r; 70 char_to_lower($S) -> $s; 71 char_to_lower($T) -> $t; 72 char_to_lower($U) -> $u; 73 char_to_lower($V) -> $v; 74 char_to_lower($W) -> $w; 75 char_to_lower($X) -> $x; 76 char_to_lower($Y) -> $y; 77 char_to_lower($Z) -> $z; 78 char_to_lower(Ch) -> Ch. 79 80 -spec char_to_upper(char()) -> char(). 81 char_to_upper($a) -> $A; 82 char_to_upper($b) -> $B; 83 char_to_upper($c) -> $C; 84 char_to_upper($d) -> $D; 85 char_to_upper($e) -> $E; 86 char_to_upper($f) -> $F; 87 char_to_upper($g) -> $G; 88 char_to_upper($h) -> $H; 89 char_to_upper($i) -> $I; 90 char_to_upper($j) -> $J; 91 char_to_upper($k) -> $K; 92 char_to_upper($l) -> $L; 93 char_to_upper($m) -> $M; 94 char_to_upper($n) -> $N; 95 char_to_upper($o) -> $O; 96 char_to_upper($p) -> $P; 97 char_to_upper($q) -> $Q; 98 char_to_upper($r) -> $R; 99 char_to_upper($s) -> $S; 100 char_to_upper($t) -> $T; 101 char_to_upper($u) -> $U; 102 char_to_upper($v) -> $V; 103 char_to_upper($w) -> $W; 104 char_to_upper($x) -> $X; 105 char_to_upper($y) -> $Y; 106 char_to_upper($z) -> $Z; 107 char_to_upper(Ch) -> Ch. 108 109 %% Tests. 110 111 -ifdef(TEST). 112 capitalize_token_test_() -> 113 Tests = [ 114 {<<"heLLo-woRld">>, <<"Hello-World">>}, 115 {<<"Sec-Websocket-Version">>, <<"Sec-Websocket-Version">>}, 116 {<<"Sec-WebSocket-Version">>, <<"Sec-Websocket-Version">>}, 117 {<<"sec-websocket-version">>, <<"Sec-Websocket-Version">>}, 118 {<<"SEC-WEBSOCKET-VERSION">>, <<"Sec-Websocket-Version">>}, 119 {<<"Sec-WebSocket--Version">>, <<"Sec-Websocket--Version">>}, 120 {<<"Sec-WebSocket---Version">>, <<"Sec-Websocket---Version">>} 121 ], 122 [{H, fun() -> R = capitalize_token(H) end} || {H, R} <- Tests]. 123 -endif.