Add '$' syntax as a shortcut for 'field' in Painless

modules/lang-painless/src/main/antlr/PainlessLexer.g4

@@ -22,6 +22,7 @@ LBRACE:    '[';
 RBRACE:    ']';
 LP:        '(';
 RP:        ')';
+DOLLAR:    '$';
 // We switch modes after a dot to ensure there are not conflicts
 // between shortcuts and decimal values.  Without the mode switch
 // shortcuts such as id.0.0 will fail because 0.0 will be interpreted

modules/lang-painless/src/main/antlr/PainlessLexer.tokens

@@ -6,153 +6,155 @@ LBRACE=5
 RBRACE=6
 LP=7
 RP=8
-DOT=9
-NSDOT=10
-COMMA=11
-SEMICOLON=12
-IF=13
-IN=14
-ELSE=15
-WHILE=16
-DO=17
-FOR=18
-CONTINUE=19
-BREAK=20
-RETURN=21
-NEW=22
-TRY=23
-CATCH=24
-THROW=25
-THIS=26
-INSTANCEOF=27
-BOOLNOT=28
-BWNOT=29
-MUL=30
-DIV=31
-REM=32
-ADD=33
-SUB=34
-LSH=35
-RSH=36
-USH=37
-LT=38
-LTE=39
-GT=40
-GTE=41
-EQ=42
-EQR=43
-NE=44
-NER=45
-BWAND=46
-XOR=47
-BWOR=48
-BOOLAND=49
-BOOLOR=50
-COND=51
-COLON=52
-ELVIS=53
-REF=54
-ARROW=55
-FIND=56
-MATCH=57
-INCR=58
-DECR=59
-ASSIGN=60
-AADD=61
-ASUB=62
-AMUL=63
-ADIV=64
-AREM=65
-AAND=66
-AXOR=67
-AOR=68
-ALSH=69
-ARSH=70
-AUSH=71
-OCTAL=72
-HEX=73
-INTEGER=74
-DECIMAL=75
-STRING=76
-REGEX=77
-TRUE=78
-FALSE=79
-NULL=80
-PRIMITIVE=81
-DEF=82
-ID=83
-DOTINTEGER=84
-DOTID=85
+DOLLAR=9
+DOT=10
+NSDOT=11
+COMMA=12
+SEMICOLON=13
+IF=14
+IN=15
+ELSE=16
+WHILE=17
+DO=18
+FOR=19
+CONTINUE=20
+BREAK=21
+RETURN=22
+NEW=23
+TRY=24
+CATCH=25
+THROW=26
+THIS=27
+INSTANCEOF=28
+BOOLNOT=29
+BWNOT=30
+MUL=31
+DIV=32
+REM=33
+ADD=34
+SUB=35
+LSH=36
+RSH=37
+USH=38
+LT=39
+LTE=40
+GT=41
+GTE=42
+EQ=43
+EQR=44
+NE=45
+NER=46
+BWAND=47
+XOR=48
+BWOR=49
+BOOLAND=50
+BOOLOR=51
+COND=52
+COLON=53
+ELVIS=54
+REF=55
+ARROW=56
+FIND=57
+MATCH=58
+INCR=59
+DECR=60
+ASSIGN=61
+AADD=62
+ASUB=63
+AMUL=64
+ADIV=65
+AREM=66
+AAND=67
+AXOR=68
+AOR=69
+ALSH=70
+ARSH=71
+AUSH=72
+OCTAL=73
+HEX=74
+INTEGER=75
+DECIMAL=76
+STRING=77
+REGEX=78
+TRUE=79
+FALSE=80
+NULL=81
+PRIMITIVE=82
+DEF=83
+ID=84
+DOTINTEGER=85
+DOTID=86
 '{'=3
 '}'=4
 '['=5
 ']'=6
 '('=7
 ')'=8
-'.'=9
-'?.'=10
-','=11
-';'=12
-'if'=13
-'in'=14
-'else'=15
-'while'=16
-'do'=17
-'for'=18
-'continue'=19
-'break'=20
-'return'=21
-'new'=22
-'try'=23
-'catch'=24
-'throw'=25
-'this'=26
-'instanceof'=27
-'!'=28
-'~'=29
-'*'=30
-'/'=31
-'%'=32
-'+'=33
-'-'=34
-'<<'=35
-'>>'=36
-'>>>'=37
-'<'=38
-'<='=39
-'>'=40
-'>='=41
-'=='=42
-'==='=43
-'!='=44
-'!=='=45
-'&'=46
-'^'=47
-'|'=48
-'&&'=49
-'||'=50
-'?'=51
-':'=52
-'?:'=53
-'::'=54
-'->'=55
-'=~'=56
-'==~'=57
-'++'=58
-'--'=59
-'='=60
-'+='=61
-'-='=62
-'*='=63
-'/='=64
-'%='=65
-'&='=66
-'^='=67
-'|='=68
-'<<='=69
-'>>='=70
-'>>>='=71
-'true'=78
-'false'=79
-'null'=80
-'def'=82
+'$'=9
+'.'=10
+'?.'=11
+','=12
+';'=13
+'if'=14
+'in'=15
+'else'=16
+'while'=17
+'do'=18
+'for'=19
+'continue'=20
+'break'=21
+'return'=22
+'new'=23
+'try'=24
+'catch'=25
+'throw'=26
+'this'=27
+'instanceof'=28
+'!'=29
+'~'=30
+'*'=31
+'/'=32
+'%'=33
+'+'=34
+'-'=35
+'<<'=36
+'>>'=37
+'>>>'=38
+'<'=39
+'<='=40
+'>'=41
+'>='=42
+'=='=43
+'==='=44
+'!='=45
+'!=='=46
+'&'=47
+'^'=48
+'|'=49
+'&&'=50
+'||'=51
+'?'=52
+':'=53
+'?:'=54
+'::'=55
+'->'=56
+'=~'=57
+'==~'=58
+'++'=59
+'--'=60
+'='=61
+'+='=62
+'-='=63
+'*='=64
+'/='=65
+'%='=66
+'&='=67
+'^='=68
+'|='=69
+'<<='=70
+'>>='=71
+'>>>='=72
+'true'=79
+'false'=80
+'null'=81
+'def'=83

modules/lang-painless/src/main/antlr/PainlessParser.g4

@@ -163,7 +163,7 @@ primary
     | listinitializer                     # listinit
     | mapinitializer                      # mapinit
     | ID                                  # variable
-    | ID arguments                        # calllocal
+    | (ID | DOLLAR) arguments             # calllocal
     | NEW type arguments                  # newobject
     ;