Grammar.txt

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left-associative: PLUS, MINUS
left-associative: MUL, DIV, FLOORDIV, MOD, PARALLEL

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Grammar
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start -> stmt_list | command

command -> ...

stmt_list  -> full_stmt start
            | END

full_stmt  -> statement PRINT

statement  -> func_def
            | list_def
            | deletion
            | expr

func_def   -> FUNC ident param_list ASSIGN func_term

param_list -> LPAREN params RPAREN

params     -> ident COMMA params
            | ident

func_term  -> expr

deletion   -> DELETE strings

strings    -> strings ident
            | ident

list_def   -> ident ASSIGN list

list       -> LBRACKET list_elem RBRACKET
            | LBRACKET FOR ident ASSIGN primary COMMA primary func_term RBRACKET
            | LBRACKET FOR ident ASSIGN primary COMMA primary COLON primary func_term RBRACKET

var_def    -> ident ASSIGN expr

list_elem  -> expr COMMA list_elem
            | expr

expr       -> expr PLUS term
            | expr MINUS term
            | term
			
term       -> term MUL sign
            | term DIV sign
            | term FLOORDIV sign
            | term MOD sign
            | term PARALLEL sign
            | sign
  
sign       -> MINUS postfix
            | PLUS postfix
            | postfix

postfix    -> primary POW sign
            | primary var
            | primary func_call
            | primary enc_expr
            | primary FACT
            | primary
		 
primary    -> ureal
            | var
            | func_call
            | enc_expr
		
var        -> ident

func_call  -> ident arg_list

arg_list   -> LPAREN args RPAREN

args       -> arg COMMA args
            | arg
	  
arg        -> list_call
            | primary
		 
enc_expr   -> LPAREN expr RPAREN
		 
ureal      -> digits DOT digits
            | digits DOT
            | DOT digits
            | ureal EXP digits
            | ureal EXP PLUS digits
            | ureal EXP MINUS digits
            | digits

digits     -> digits DIGIT
            | DIGIT

ident      -> ALPHA chars
            | UNDERSCORE chars

chars      -> chars char
            | char

char       -> DIGIT | ALPHA | UNDERSCORE

ALPHA      -> 'a' | 'b' | 'c' | ... | 'z' | 'A' | 'B' | ... | 'Z'
DIGIT      -> '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
UNDERSCORE -> '_'
EXP        -> 'e' | 'E'
DOT        -> '.'
PLUS       -> '+'
MINUS      -> '-'
MUL        -> '*'
DIV        -> '/'
FLOORDIR   -> '//' | 'div'
MOD        -> '%' | 'mod'
FACT       -> '!'
LPAREN     -> '('
RPAREN     -> ')'
PARALLEL   -> '||'
POW        -> '^' | '**'
COMMA      -> ','
COLON      -> ':'
PRINT      -> '\n' | ';'
FUNC       -> 'fn'
DELETE     -> 'del'
ASSIGN     -> '='
END        -> <EOF>

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Compact grammar (e.g., ANTLR notation?) -- INCOMPLETE
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grammar MathParser;

expr:			term ((PLUS|MINUS) term)*
term:			sign ((MUL|DIV|FLOORDIV|MOD|PARALLEL) sign)*
sign:			(MINUS|PLUS)? postfix
postifx:		primary (POW sign|identifier|enc_expr|FACT)*
primary:		number|enc_expr
enc_expr:		LPAREN expr RPAREN
number:			...
ident:			('_'|alpha) ('_'|alpha|digit)*
alpha:			['a'-'z'] | ['A'-'Z']
digit:			['0'-'9']