COMMENT in Sources/AngouriMath/Core/Antlr/AngouriMath.g is
COMMENT: ('//' ~[\r\n]* '\r'? '\n' | '/*' .*? '*/') -> skip ;The // alternative only matches when a newline follows, so a line comment that ends the input never matches at all and its / reaches the parser as an operator.
Measured on a build of master (9b6fb5b):
MathS.FromString("x + 1 // done"); // UnhandledParseException: line 1:7 extraneous input '/'
MathS.FromString("x + 1 // done\n"); // x + 1
MathS.FromString("x + 1 /* done */"); // x + 1The end of the input is where a comment is most likely to be written — the last line of a file, or a single-line string handed to FromString — and the block form carries no such condition, so this reads as a missing optional rather than a decision. Making the newline optional (('\r'? '\n')?) is what I would expect to fix it.
Not fixed in the documentation PR that found it, since a grammar change means regenerating the ANTLR parser under Docs/Contributing/ImproveParser.md and is its own change with its own risk. Written down as behaviour in Docs/Usage/Syntax.md meanwhile.
Found while deriving what the grammar accepts for #746 item 8.
COMMENTinSources/AngouriMath/Core/Antlr/AngouriMath.gisThe
//alternative only matches when a newline follows, so a line comment that ends the input never matches at all and its/reaches the parser as an operator.Measured on a build of
master(9b6fb5b):The end of the input is where a comment is most likely to be written — the last line of a file, or a single-line string handed to
FromString— and the block form carries no such condition, so this reads as a missing optional rather than a decision. Making the newline optional (('\r'? '\n')?) is what I would expect to fix it.Not fixed in the documentation PR that found it, since a grammar change means regenerating the ANTLR parser under
Docs/Contributing/ImproveParser.mdand is its own change with its own risk. Written down as behaviour inDocs/Usage/Syntax.mdmeanwhile.Found while deriving what the grammar accepts for #746 item 8.