msg: Attempt to generalize the MSG Structure class

If things turn out this will be the base for ASN1,
GSM, ISUP, BSSAP, SCCP and the other protocols

MSG.st

@@ -0,0 +1,149 @@
+"
+ (C) 2011 by Holger Hans Peter Freyther
+ All Rights Reserved
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as
+ published by the Free Software Foundation, either version 3 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"
+
+"
+The next attempt to generalize the message pattern. We will just describe
+messages that have a type, mandantory and optional parameters. The parameters
+will be simple ids. There should be code to generate nice parsing routines
+"
+
+Object subclass: MSGStructure [
+    | type mandantory variable optional |
+    <comment: 'Attempt to have a DSL for messages'>
+
+    MSGStructure class >> initWith: aType [
+        ^ self new
+            instVarNamed: #type put: aType; yourself
+    ]
+
+    type [
+        <category: 'The type of this message'>
+        ^ type
+    ]
+
+    addMandantory: aType [
+        self mandantory add: aType.
+    ]
+
+    addOptional: aType [
+        self optional add: aType.
+    ]
+
+    addOptionals: aType [
+        "Optional Parameters that may appear more than once."
+        self optional add: aType.
+    ]
+
+    addVariable: aType [
+        self variable add: aType.
+    ]
+
+    mandantory [
+        <category: 'private'>
+        ^ mandantory ifNil: [mandantory := OrderedCollection new]
+    ]
+
+    variable [
+        <category: 'private'>
+        ^ variable ifNil: [variable := OrderedCollection new]
+    ]
+
+    optional [
+        <category: 'private'>
+        ^ optional ifNil: [optional := OrderedCollection new]
+    ]
+]
+
+Object subclass: MSGField [
+    <category: 'osmo-networking'>
+    <comment: 'The description of a Information Element'>
+    | par name length maxLength |
+
+    name [
+        <category: 'accessing'>
+        ^ name
+    ]
+
+    parameterValue [
+        <category: 'accessing'>
+        ^ par
+    ]
+
+    octalLength [
+        <category: 'accessing'>
+        ^ length
+    ]
+
+    maxLength [
+        <category: 'accessing'>
+        ^ maxLength
+    ]
+
+    isVarible [
+        "If this field is variable in length"
+        ^ self subclassResponsibility
+    ]
+
+    isFixed [
+        "If this field is of a fixed length"
+        ^ self subclassResponsibility
+    ]
+]
+
+Object subclass: MSGFixedField [
+    MSGFixedField class [
+        initWith: aName parameter: aParm octalLength: aLen [
+            ^ self new
+                instVarNamed: #name put: aName;
+                instVarNamed: #par  put: aParm;
+                instVarNamed: #length put: aLen;
+                yourself
+        ]
+    ]
+
+    isVarible [ ^ false ]
+    isFixed   [ ^ true  ]
+]
+
+Object subclass: MSGVariableField [
+    MSGVariableField class [
+        initWith: aName parameter: aParm
+            minOctalLength: aLen [
+
+            ^ self new
+                instVarNamed: #name put: aName;
+                instVarNamed: #par put: aParm;
+                instVarNamed: #length put: aLen;
+                yourself
+        ]
+
+        initWith: aName parameter: aParm
+            minOctalLength: aMin maxOctalLength: aMax [
+            ^ self new
+                instVarNamed: #name put: aName;
+                instVarNamed: #par put: aParm;
+                instVarNamed: #length put: aMin;
+                instVarNamed: #maxLength put: aMax;
+                yourself
+            
+        ]
+    ]
+
+    isVarible [ ^ true  ]
+    isFixed   [ ^ false ]
+]

package.xml

@@ -5,6 +5,7 @@
     <prereq>OsmoLogging</prereq>
 
     <filein>Extensions.st</filein>
+    <filein>MSG.st</filein>
     <filein>ISUP.st</filein>
     <filein>IPAConstants.st</filein>
     <filein>IPADispatcher.st</filein>
@@ -25,6 +26,7 @@
 
 
     <file>Extensions.st</file>
+    <file>MSG.st</file>
     <file>ISUP.st</file>
     <file>IPAConstants.st</file>
     <file>IPADispatcher.st</file>