antlr4 - ANTLR v4 grammar fails to parse due to mismatched EOF -

follows simple grammar antlr v4. grammar when walked produces error message **line 1:14 mismatched input '' expecting dimensionname*

for trivial input such "sdarsfd integer" (without quotation marks).

so has mention f similar errors , bug perhaps filed in 4.3 timeframe. have been using antlr 4.5.

any help/pointer/solution?

/**   simple parser dimension declaration */ grammar simple; definition : dim; dim : dimensionname datatype;  dimensionname : letter (letter)*; // greedy datatype: 'integer' | 'decimal'; letter : [a-za-z]; digit : [0-9];  ws: [ \t\n\r]+ -> skip; 

you have switch 2 lexer rules datatype , dimensionname

... datatype: 'integer' | 'decimal'; dimensionname : letter (letter)*; // greedy ... 

as dimensionname matches every chars, 'integer' typed dimensionname instead of datatype. "sdarsfd integer", lexer produces 2 dimensionname token, dim rule cannot matched. switching 2 lexer rules, lexer produces dimensionname token , datatype token match dim rule.

also, can define letter , digit fragment:

fragment letter : [a-za-z]; fragment digit : [0-9]; 

unless want them matched independent token (in grammar, "a" typed letter).