Has anyone written a guide on creating BASIC?

[BigDumbDinosaur]

Speaking of unary minuses, in Thoroughbred BASIC, one cannot write PRINT 4 * -1, as it will generate a syntax error. However, PRINT 4 * (-1) will successfully evaluate, as will PRINT -1 * 4. Evidently, the grammar parser chokes if two operator tokens are in succession.