Class: XDRScanner (in SunRPC)

• Inheritance
• Description
• Class protocol
  • initialization
• Instance protocol
  • accessing
  • initialization
  • private
  • reading next token
  • specials

Inheritance:

   Object
   |
   +--Scanner
      |
      +--SunRPC::XDRScanner

Package:

stx:goodies/communication

Category:

Net-Communication-SunRPC-XDR_IDL

Version:

rev: 1.17 date: 2024/04/22 17:44:58

user: stefan

file: SunRPC_XDRScanner.st directory: goodies/communication

module: stx stc-classLibrary: communication

Description:

scanner for XDR-definition files - provides token scanning functionality
for the XDRParser. (normally not used by its own).
XDR is the IDL of SunRPC.

copyright
COPYRIGHT (c) 2002 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

syntax
<<END
      declaration:
	   type-specifier identifier
	 | type-specifier identifier "[" value "]"
	 | type-specifier identifier "<" [ value ] ">"
	 | "opaque" identifier "[" value "]"
	 | "opaque" identifier "<" [ value ] ">"
	 | "string" identifier "<" [ value ] ">"
	 | type-specifier "*" identifier
	 | "void"

      value:
	   constant
	 | identifier

      type-specifier:
	   [ "unsigned" ] "int"
	 | [ "unsigned" ] "hyper"
	 | "float"
	 | "double"
	 | "bool"
	 | enum-type-spec
	 | struct-type-spec
	 | union-type-spec
	 | identifier

      enum-type-spec:
	 "enum" enum-body

      enum-body:
	 "{"
	    ( identifier "=" value )
	    ( "," identifier "=" value )*
	 "}"

      struct-type-spec:
	 "struct" struct-body

      struct-body:
	 "{"
	    ( declaration ";" )
	    ( declaration ";" )*
	 "}"

      union-type-spec:
	 "union" union-body

      union-body:
	 "switch" "(" declaration ")" "{"
	    ( "case" value ":" declaration ";" )
	    ( "case" value ":" declaration ";" )*
	    [ "default" ":" declaration ";" ]
	 "}"

      constant-def:
	 "const" identifier "=" constant ";"

      type-def:
	   "typedef" declaration ";"
	 | "enum" identifier enum-body ";"
	 | "struct" identifier struct-body ";"
	 | "union" identifier union-body ";"

      program-def:
	 "program" identifier "{"
	    version-def
	    version-def *
	 "}" "=" constant ";"

      version-def:
	 "version" identifier "{"
	     procedure-def
	     procedure-def *
	 "}" "=" constant ";"

      procedure-def:
	 type-specifier identifier "(" type-specifier
	   ("," type-specifier )* ")" "=" constant ";"

      definition:
	   type-def
	 | constant-def
	 | program-def

      specification:
	   definition *
END"

Class protocol:

 initialize

(comment from inherited method)
initialize the classes defaults. Typically, these are changed
later in the 'private.rc' file.

 setupActions

initialize the scanners actionTables - these are used to dispatch
into scanner methods as characters are read

Usage example(s):

XDRScanner setupActions

 update: something with: parameter from: changedObject

bug work-around (compiled cheap blocks loose their code)

Instance protocol:

 newSource: aStringOrStream

 source

 initialize

initialize the scanner

 checkForKeyword: string

check if string is a keyword (as opposed to an identifier).

 isCommentCharacter: ch

return true, if ch is the comment-start character

 pushBack: aToken

 skipForClosing: closingToken with: openingToken

 nextCharacter

a single quote has been scanned; scan the character-string (caring for quotes).
TODO: C-escapes; \0xx; \0xxx

 nextEq

'=' has been read - look for another '='

 nextGT

'>' has been read - look for another '>'

 nextLT

'<' has been read - look for another '<'

 nextMinus

'-' has been read - look for another '-'

 nextNumber

a digit has been read; scan a number (0xfoo / 0octal / decimal or float).
if specialFloat is true, return float value as hi.low (for version numbers)

 nextPlus

'+' has been read - look for another '+'

 nextSlash

'/' has been read - next could be:
'/' - EOL comment
'*' - regular comment

 nextString

a doubled quote has been scanned; scan the string (caring for doubled quotes

 nextToken

return the next token from my source-stream

 readingStream: aStream do: aBlock

 restOfLine