var x = 9
var y = 15.0
(x..15)  // evaluate to Range<Integer>.open(x,15)
[x..15) // evaluate to Range<Integer>.closedOpen(x, 15)
[x..y]  // error, x and y have different types

@Override
XOtherOperatorExpression returns XExpression:
	{Range}
	(open='('|'[' left=XAdditiveExpression  '..' right=XAdditiveExpression close= ')'|']') | super
;

/**
 * RetokenizingTokenSource accomodates backtracking limitations in the ANTRL lexer when used from Xtext.
 * 
 * The problem is the three overlapping syntaxes
 * INT.INT leading to a Floating Point lteral
 * INT..INT leading to a Collection range
 * INT.ID leading to a numeric navigation
 * 
 * ANTLR proceeds to INT. but won't backup when the character after the . is bad.
 * 
 * The code here allows the basic lexer to be ignorant of floating point syntax so that it correctly parses
 * INT.INT as INT DOT INT
 * INT..INT as INT DOTDOT INT
 * INT.INTe+INT as INT DOT INT ID PLUS INT
 * so the code here recognises the floating point literal and reconsttructs. As an additional benefit 'e' and 'E' are not keywords.
 */

error(211): ../...omitted.../parser/antlr/internal/InternalScg.g:238:2: [fatal] rule ruleXOtherOperatorExpression has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2.  Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:238:2: Decision can match input such as "'(' ']'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Semantic predicates were present but were hidden by actions.
warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:2449:6: Decision can match input such as "')'" using multiple alternatives: 2, 3
As a result, alternative(s) 3 were disabled for that input
Semantic predicates were present but were hidden by actions.
error(201): ../...omitted.../antlr/internal/InternalScg.g:2449:6: The following alternatives can never be matched: 3
warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:2994:3: Decision can match input such as "{RULE_STRING..RULE_DECIMAL, ']'..')', '['..'(', '{', '<', '+'..'-', '!', '#', 'if', 'switch', 'for'..'do', 'super'..'try', 'synchronized'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Semantic predicates were present but were hidden by actions.
error(201): ../...omitted.../parser/antlr/internal/InternalScg.g:2994:3: The following alternatives can never be matched: 2

warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:3246:3: Decision can match input such as "{RULE_ID..RULE_DECIMAL, ']'..')', '['..'(', '{', '<', '+'..'-', '!', '#', 'if', 'switch', 'for'..'try', 'synchronized'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Semantic predicates were present but were hidden by actions.
error(211): ../...omitted.../parser/antlr/internal/InternalScg.g:4067:3: [fatal] rule ruleXBasicForLoopExpression has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2.  Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:4767:4: Decision can match input such as "')'" using multiple alternatives: 2, 3
As a result, alternative(s) 3 were disabled for that input
Semantic predicates were present but were hidden by actions.
error(201): ../...omitted.../antlr/internal/InternalScg.g:4767:4: The following alternatives can never be matched: 3

warning(200): ../...omitted.../parser/antlr/internal/InternalScg.g:5100:4: Decision can match input such as "')'" using multiple alternatives: 2, 3
As a result, alternative(s) 3 were disabled for that input
Semantic predicates were present but were hidden by actions.
error(201): ../...omitted.../parser/antlr/internal/InternalScg.g:5100:4: The following alternatives can never be matched: 3

@Override
XOtherOperatorExpression returns XExpression:
	{Range}
	(open=('('|'[') left=XAdditiveExpression  '..' right=XAdditiveExpression) close= (')'|']') | super
;

error(211): ../..omitted../parser/antlr/internal/InternalScg.g:238:2: [fatal] rule ruleXOtherOperatorExpression has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2.  Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
3916 [main] INFO  text.xtext.generator.XtextGenerator  - Generating common infrastructure
...