1/***************************************************************************************************
  2 F7 This is the main grammar file for F7 code. The goal is to get **near feature-parity** with most
  3 major spreadsheet applications. In cases of conflicting syntax, we choose the simpler of the two,
  4 or the most compatible, which is mostly a judgment call. In cases where features are grand-fathered
  5 in from older versions of the major spreadsheet applications we may choose to ignore those features
  6 altogether.
  7 
  8 Comments are collapsed into the main block of each section below. If we write comments for each
  9 rule (and believe me, we could) it would end up being difficult to read. We therefore condense them
 10 down to general comments in the main block.
 11 ***************************************************************************************************
 12 */
 13grammar F7;
 14
 15/***************************************************************************************************
 16 PARSER RULES These are rules that the parser will use. Some of them are explicitly named (def: ...
 17 ; ... ;) and some are named with the # character at the end of the individual rule.
 18 
 19 start - The starting block is the main entry point for parsing, but not for compilation or the
 20 logic of F7 code. It basically serves as a way to captutre the code and the EOF, so we can jump
 21 straight to the block.
 22 
 23 block - All F7 code starts with a single expression.
 24 
 25 expression - An expression is a section of code.
 26 
 27 atom - An atom is a single variable that itself requires no execution or reduction, but may contain
 28 other atoms and expressions that do require execution and reduction.
 29 
 30 identifier - An identifier is a set of characters and numbers between 1 and N in length, starting
 31 with an alphabetical character. It may contain periods and underscores as long as they are not in
 32 beginning the string.
 33 
 34 comparisionOperator - Short hand for all comparision operators.
 35 ***************************************************************************************************
 36 */
 37start: block EOF;
 38block: expression;
 39expression:
 40	Minus expression		# unaryMinusExpression
 41	| Plus expression		# unaryPlusExpression
 42	| expression Percent+	# unaryPercentExpression
 43	// TODO:HACK - <assoc=left> vs <assoc=right> differ in Excel and Sheets, respectively. Weird.
 44	| <assoc = left> left = expression op = Power right = expression	# powerExpression
 45	| left = expression op = (Multiply | Divide) right = expression		# multiplicationExpression
 46	| left = expression op = (Plus | Minus) right = expression			# additiveExpression
 47	| left = expression op = comparisonOperator right = expression		# relationalExpression
 48	| left = expression op = Ampersand right = expression				# concatExpression
 49	| atom																# atomExpression
 50	| atom (separator = Colon atom)+									# rangeExpression;
 51atom:
 52	range												# cellAtom
 53	| String											# stringAtom
 54	| Error												# errorAtom
 55	| Int												# numberAtom
 56	| Number											# numberAtom
 57	| LeftParen expression RightParen					# parentheticalAtom
 58	| name = identifier LeftParen arguments RightParen	# formulaAtom
 59	| LeftBrace (
 60		expression (separator = (Comma | SemiColon) expression)*
 61	)? RightBrace	# listAtom
 62	| identifier	# namedAtom;
 63range:
 64	biRange
 65	| uniRange
 66	| columnWiseBiRange
 67	| columnWiseWithRowOffsetFirstBiRange
 68	| columnWiseWithRowOffsetLastBiRange
 69	| rowWiseBiRange
 70	| rowWiseWithColumnOffsetFirstBiRange
 71	| rowWiseWithColumnOffsetLastBiRange;
 72biRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn = NCharacters absoRow =
 73		Dollar? firstRow = Int Colon absoLastColumn = Dollar? lastColumn = NCharacters absoLastRow =
 74		Dollar? lastRow = Int;
 75uniRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn = NCharacters absoFirstRow =
 76		Dollar? firstRow = Int;
 77columnWiseBiRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn = NCharacters Colon
 78		absoLastColumn = Dollar? lastColumn = NCharacters;
 79columnWiseWithRowOffsetFirstBiRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn =
 80		NCharacters absoFirstRow = Dollar? firstRow = Int Colon absoLastColumn = Dollar? lastColumn
 81		= NCharacters;
 82columnWiseWithRowOffsetLastBiRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn =
 83		NCharacters Colon absoLastColumn = Dollar? lastColumn = NCharacters absoLastRow = Dollar?
 84		lastRow = Int;
 85rowWiseBiRange: (grid = gridName Bang)? absoFirstRow = Dollar? firstRow = Int Colon absoLastRow =
 86		Dollar? lastRow = Int;
 87rowWiseWithColumnOffsetFirstBiRange: (grid = gridName Bang)? absoFirstColumn = Dollar? firstColumn =
 88		NCharacters absoFirstRow = Dollar? firstRow = Int Colon absoLastRow = Dollar? lastRow = Int;
 89rowWiseWithColumnOffsetLastBiRange: (grid = gridName Bang)? absoFirstRow = Dollar? firstRow = Int
 90		Colon absLastColumn = Dollar? lastColumn = NCharacters absoLastRow = Dollar? lastRow = Int;
 91arguments: (expression (Comma expression)*)?;
 92gridName: SingleQuoteString | identifier;
 93identifier: NCharacters (Dot | Underscore | NCharacters | Int)*;
 94comparisonOperator:
 95	LessThanOrEqualTO
 96	| GreaterThanOrEqualTo
 97	| LessThan
 98	| GreaterThan
 99	| Equal
100	| NotEqual;
101
102/***************************************************************************************************
103 LEXER RULES These are rules that the lexer will use. They SHOULD BE NON-CONFLICTING, and as
104 small/big as they need to be.
105 ***************************************************************************************************
106 */
107NCharacters: CHARACTER+;
108Dot: '.';
109Int: DIGIT+;
110Number:
111	DIGIT+ (Dot DIGIT+)? (E ('+' | '-')? DIGIT+ (Dot DIGIT+)?)?;
112SingleQuoteString: SINGLE_QUOTE_STRING;
113String: STRING_LITERAL;
114Error: ERROR_LITERAL;
115LeftParen: LPAREN;
116RightParen: RPAREN;
117LeftBrace: LBRACE;
118RightBrace: RBRACE;
119Comma: COMMA;
120Colon: COLON;
121SemiColon: SEMICOLON;
122Bang: BANG;
123Plus: PLUS;
124Minus: MINUS;
125Percent: PERCENT;
126Power: POW;
127Divide: DIV;
128Multiply: MULT;
129GreaterThan: GT;
130GreaterThanOrEqualTo: GTEQ;
131LessThan: LT;
132LessThanOrEqualTO: LTEQ;
133Equal: EQ;
134NotEqual: NEQ;
135Ampersand: AMPERSAND;
136Dollar: DOLLAR;
137Underscore: UNDERSCORE;
138
139/***************************************************************************************************
140 LEXER FRAGMENTS Rules that the lexer will use, but we don't need to NAME.
141 
142 Fragments A-Z let us to do case-insensitivity when it comes to literally named things like errors.
143
144
145 Error literals look weird because we're using the case-insensitive alphabet fragments.
146 ***************************************************************************************************
147 */
148fragment A: [aA];
149fragment B: [bB];
150fragment C: [cC];
151fragment D: [dD];
152fragment E: [eE];
153fragment F: [fF];
154fragment G: [gG];
155fragment H: [hH];
156fragment I: [iI];
157fragment J: [jJ];
158fragment K: [kK];
159fragment L: [lL];
160fragment M: [mM];
161fragment N: [nN];
162fragment O: [oO];
163fragment P: [pP];
164fragment Q: [qQ];
165fragment R: [rR];
166fragment S: [sS];
167fragment T: [tT];
168fragment U: [uU];
169fragment V: [vV];
170fragment W: [wW];
171fragment X: [xX];
172fragment Y: [yY];
173fragment Z: [zZ];
174fragment IDENTIFIER: CHARACTER+ ('_' | CHARACTER)*;
175fragment DIGIT: ('0' ..'9');
176fragment CHARACTER: [a-zA-Z];
177fragment ERROR_LITERAL:
178	HASH N U L L BANG // #NULL!
179	| HASH D I V DIV '0' BANG // #DIV/0!
180	| HASH V A L U E BANG // #VALUE!
181	| HASH R E F BANG // #REF!
182	| HASH N A M E QUESTION // #NAME?
183	| HASH N U M BANG // #NUM!
184	| HASH N DIV A // #N/A
185	| HASH E R R O R BANG; // #ERROR!
186fragment SINGLE_QUOTE_STRING: (
187		'\'' SINGLE_STRING_CHARACTER* '\''
188	);
189fragment SINGLE_STRING_CHARACTER: ~['\\\r\n];
190fragment STRING_LITERAL: ('"' DOUBLE_STRING_CHARACTER* '"');
191fragment DOUBLE_STRING_CHARACTER: ~["\\\r\n];
192fragment EQ: '=';
193fragment NEQ: '<>';
194fragment GT: '>';
195fragment LT: '<';
196fragment GTEQ: '>=';
197fragment LTEQ: '<=';
198fragment PLUS: '+';
199fragment MINUS: '-';
200fragment MULT: '*';
201fragment DIV: '/';
202fragment PERCENT: '%';
203fragment HASH: '#';
204fragment POW: '^';
205fragment AMPERSAND: '&';
206fragment LPAREN: '(';
207fragment RPAREN: ')';
208fragment COMMA: ',';
209fragment SEMICOLON: ';';
210fragment LBRACE: '{';
211fragment RBRACE: '}';
212fragment BANG: '!';
213fragment QUESTION: '?';
214fragment DOLLAR: '$';
215fragment COLON: ':';
216fragment UNDERSCORE: '_';
217
218/***************************************************************************************************
219 UTIL/COMMON/ETC.
220 ***************************************************************************************************
221 */
222// Skip whitespaces in between tokens.
223// Allows us to match on whitespace inside strings, but ignore them otherwise.
224WS: [ \r\n\t]+ -> skip;