From 3c15ff32e89e401b4dde2b8acc9699be2614b996 Mon Sep 17 00:00:00 2001
From: Anders Svensson <anders@erlang.org>
Date: Wed, 18 May 2011 18:29:12 +0200
Subject: Initial commit of the diameter application.

The application provides an implementation of the Diameter protocol
as defined in RFC 3588.
---
 lib/diameter/src/compiler/diameter_spec_scan.erl | 157 +++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 lib/diameter/src/compiler/diameter_spec_scan.erl

(limited to 'lib/diameter/src/compiler/diameter_spec_scan.erl')

diff --git a/lib/diameter/src/compiler/diameter_spec_scan.erl b/lib/diameter/src/compiler/diameter_spec_scan.erl
new file mode 100644
index 0000000000..bc0448882a
--- /dev/null
+++ b/lib/diameter/src/compiler/diameter_spec_scan.erl
@@ -0,0 +1,157 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2010-2011. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(diameter_spec_scan).
+
+%%
+%% Functions used by the spec file parser in diameter_spec_util.
+%%
+
+-export([split/1,
+         split/2,
+         parse/1]).
+
+%%% -----------------------------------------------------------
+%%% # parse/1
+%%%
+%%% Output: list of Token
+%%%
+%%%         Token = '{' | '}' | '<' | '>' | '[' | ']'
+%%%               | '*' | '::=' | ':' | ',' | '-'
+%%%               | {name, string()}
+%%%               | {tag, atom()}
+%%%               | {number, integer() >= 0}
+%%%
+%%% Tokenize a string. Fails if the string does not parse.
+%%% -----------------------------------------------------------
+
+parse(S) ->
+    parse(S, []).
+
+%% parse/2
+
+parse(S, Acc) ->
+    acc(split(S), Acc).
+
+acc({T, Rest}, Acc) ->
+    parse(Rest, [T | Acc]);
+acc("", Acc) ->
+    lists:reverse(Acc).
+
+%%% -----------------------------------------------------------
+%%% # split/2
+%%%
+%%% Output: {list() of Token, Rest}
+%%%
+%%% Extract a specified number of tokens from a string. Returns a list
+%%% of length less than the specified number if there are less than
+%%% this number of tokens to be parsed.
+%%% -----------------------------------------------------------
+
+split(Str, N)
+  when N >= 0 ->
+    split(N, Str, []).
+
+split(0, Str, Acc) ->
+    {lists:reverse(Acc), Str};
+
+split(N, Str, Acc) ->
+    case split(Str) of
+        {T, Rest} ->
+            split(N-1, Rest, [T|Acc]);
+        "" = Rest ->
+            {lists:reverse(Acc), Rest}
+    end.
+
+%%% -----------------------------------------------------------
+%%% # split/1
+%%%
+%%% Output: {Token, Rest} | ""
+%%%
+%%% Extract the next token from a string.
+%%% -----------------------------------------------------------
+
+split("" = Rest) ->
+    Rest;
+
+split("::=" ++ T) ->
+    {'::=', T};
+
+split([H|T])
+  when H == ${; H == $};
+       H == $<; H == $>;
+       H == $[; H == $];
+       H == $*; H == $:; H == $,; H == $- ->
+    {list_to_atom([H]), T};
+
+split([H|T]) when $A =< H, H =< $Z;
+                  $0 =< H, H =< $9 ->
+    {P, Rest} = splitwith(fun is_name_ch/1, [H], T),
+    Tok = try
+              {number, read_int(P)}
+          catch
+              error:_ ->
+                  {name, P}
+          end,
+    {Tok, Rest};
+
+split([H|T]) when $a =< H, H =< $z ->
+    {P, Rest} = splitwith(fun is_name_ch/1, [H], T),
+    {{tag, list_to_atom(P)}, Rest};
+
+split([H|T]) when H == $\t;
+                  H == $\s;
+                  H == $\n ->
+    split(T).
+
+%% read_int/1
+
+read_int([$0,X|S])
+  when X == $X;
+       X == $x ->
+    {ok, [N], []} = io_lib:fread("~16u", S),
+    N;
+
+read_int(S) ->
+    list_to_integer(S).
+
+%% splitwith/3
+
+splitwith(Fun, Acc, S) ->
+    split([] /= S andalso Fun(hd(S)), Fun, Acc, S).
+
+split(true, Fun, Acc, [H|T]) ->
+    splitwith(Fun, [H|Acc], T);
+split(false, _, Acc, S) ->
+    {lists:reverse(Acc), S}.
+
+is_name_ch(C) ->
+    is_alphanum(C) orelse C == $- orelse C == $_.
+
+is_alphanum(C) ->
+    is_lower(C) orelse is_upper(C) orelse is_digit(C).
+
+is_lower(C) ->
+    $a =< C andalso C =< $z.
+
+is_upper(C) ->
+    $A =< C andalso C =< $Z.
+
+is_digit(C) ->
+    $0 =< C andalso C =< $9.
-- 
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