parser port

cases in exp	status
simple_exp	✅
prec_app: NOT exp	✅
exp actual_args	✅
ARRAY_CREATE simple_exp simple_exp
prec_unary_minus: MINUS exp
MINUS_DOT exp
AST_DOT: exp AST_DOT exp
exp SLASH_DOT exp
PLUS: exp PLUS exp
exp MINUS exp
exp PLUS_DOT exp
exp MINUS_DOT exp
EQUAL (left): exp EQUAL exp
exp LESS_GREATER exp
exp LESS exp
exp GREATER exp
exp LESS_EQUAL exp
exp GREATER_EQUAL exp
COMMA: elems
LESS_MINUS: simple_exp DOT LPAREN exp RPAREN LESS_MINUS exp
prec_if: IF exp THEN exp ELSE exp
SEMICOLON: exp SEMICOLON exp
prec_let: LET IDENT EQUAL exp IN exp	🆗 (unique types are not assigned)
LET REC fundef IN exp
LET LPAREN pat RPAREN EQUAL exp IN exp