LYR-MIG0402

an operation that answered whether it worked

hint · spec 14-cli

A note of lyric fix --from-4: a silent operation of Lyric 4 answered false when it failed, file.remove(p); in Lyric 5 it throws and answers nothing, and its answer is used here.

Explanation

Lyric 4's silent forms answered: null for what gives a value, false for what does not. Lyric 5 has the throwing form alone. Where the answer was a value, the migration writes try?: file.text(p) is (try? fs.readText(p)). Where it was false, a statement is written try fs.remove(p);, and the enclosing function has to catch it or say throws.

Where the answer is used, in an if or a let, the call stays as written and the note says so: call it in a try block, and do in its catch what the false did.

Example

by hand[LYR-MIG0402] main.lyr:4:9: 'file.remove("/nothing")' answered whether it worked; in Lyric 5 it throws, and it answers nothing — call it in a 'try' block, and do in its 'catch' what the 'false' did