#% text_encoding = iso8859_1
# Copyright (C) Field Consulting and Services, Inc., 2018 all rights reserved.
########################################################################
##
## Created By: Mark Field (FCSI)
## Date: 2018/06/19
## Last Modified Time-stamp: <06/19/2018 13:47, Mark Field (FCSI)>
##
## Project Files
##
## Description:
## This is to support the new "_class" directive in smallworld
## 5.1.4+ in 4.3. Note that the class is ignored and only
## supports 1 class directive. Since this is to support
## backward compatibility, it isn't truly robust. 
##
## The following works:
##   def_slotted_exemplar(:exemplar,
##    {
##    },{:plugin},
##    	{ _class |com.gesmallworld.magik.language.MagikFinalisable|}
##    )
##   def_slotted_exemplar(:exemplar,
##    {
##    },{:plugin},{ _class |com.gesmallworld.magik.language.MagikFinalisable|}
##    )
##
## The following does not work...
##   def_slotted_exemplar(:exemplar,
##    {
##    },{:plugin},{
##         _class |com.gesmallworld.magik.language.MagikFinalisable|}
##    )

$

########################################################################
_package sw
$
user:fcsi_method_manip.fcsi_copy_method(magik_parser,:|lookahead()|)
$
_pragma(classify_level=restricted)
_method magik_parser.lookahead()
	_local lal << _self.sw!lookahead()
	_if lal.type _is :bad
	_then
		_return _self.fcsi_try_to_ignore_class_lookahead()
	_endif
	_return lal
_endmethod
$
_pragma(classify_level=restricted)
_method magik_parser.fcsi_try_to_ignore_class_lookahead()
	## Parameters  : none
	## Returns     : lexeme of :rcurley
	## Function    : handles a _class directive on same line as {}
	## See file description for examples that work in 4.3
	## Methodology : 
	#---------------- HISTORY ---------------------
	# (2018/06/19 - Mark Field (FCSI)): Created.
	#----------------------------------------------
	
	#DEBUG _global !a; !a << {_self.copy(),.input.copy(),.current_mark.copy()}

	_local cLine << .current_mark.text[.current_mark.line]
	# Tried to handle separate lines, but ran out of time...
	#_local unget? << _false 
	_try
		_if cLine.subseq(.current_lex.startcol,.current_lex.length) <> "_class"
		_then
			_return .lookahead_lex
		_endif
	_when index_out_of_bounds
	#	unget? << _true 
	#	.input.get()
	#	cLine << .current_mark.text[.current_mark.line]
	#	_if cLine.subseq(.current_lex.startcol,.current_lex.length) <> "_class"
	#	_then
	#		.input.unget()
			_return .lookahead_lex
	#	_endif
	_endtry

	_local endPipe << cLine.rindex_of(%|)
	_local nLine << cLine.subseq(1,.current_lex.startcol-1)
	_local rCurleyPos << nLine.size
	nLine +<< cLine.subseq(endPipe+1)
	.input.sys!slot(:text)[.current_mark.line] << nLine
	.input.sys!slot(:lex)[.current_mark.line][.current_mark.lex] <<
		lexeme.new(:rcurly,_unset,_unset,rCurleyPos,1)

	.input.scan_line(.current_mark.line)
	#DEBUG !a << {_self.copy(),.input.copy(),.current_mark.copy()}
	.current_lex << .lookahead_lex <<
		.input.sys!slot(:lex)[.current_mark.line][.current_mark.lex]
	_return .lookahead_lex
_endmethod
$