$ rustc LowercaseFilter.rs error[E0425]: cannot find function `getcodepoint` in this scope --> LowercaseFilter.rs:9:8 | 9 | while getcodepoint(c) { | ^^^^^^^^^^^^ not found in this scope error[E0425]: cannot find function `tolower` in this scope --> LowercaseFilter.rs:10:16 | 10 | putcodepoint(tolower(c)); | ^^^^^^^ not found in this scope error[E0425]: cannot find function `putcodepoint` in this scope --> LowercaseFilter.rs:10:3 | 10 | putcodepoint(tolower(c)); | ^^^^^^^^^^^^ not found in this scope error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0425`.