CODEWITHSUNDEEP
swift
Costello
Costello

Reputation: 115

Line control statement in swift

i am reading swift from apple docs and learning about statements. but couldnot find any information about the Line Control Statements.

According to the docs

A line control statement is used to specify a line number and filename that can be different from the line number and filename of the source code being compiled. Use a line control statement to change the source code location used by Swift for diagnostic and debugging purposes.

A line control statement has the following forms:

#sourceLocation(file: filename, line: line number)
#sourceLocation()

My question is when should i use it? The docs lags an example about the topic.Any links or some hints would be helpful.

Upvotes: 2

Views: 389

Answers (2)

Rob
Rob

Reputation: 437422

Unfortunately, #sourceLocation seriously diminishes its utility because it only accepts string literal for the file and integer literal for the line. In the revision discussion to SE-0034, it was suggested that #sourceLocation “is not a widely visible end-user feature”.

I really wish it accepted a normal string and integer values (e.g., that I could capture #file and #line, and pass that to #sourceLocation). That would be extremely useful. E.g., Xcode 15 has a feature that lets you jump from a OSLog or Logger message in the console to a line of code in your project, and this feature honors #sourceLocation. Right now, all my logging messages take me to my logging utility library rather than to the #file and #line that originated the logging message. A squandered opportunity, IMHO.

Bottom line, #sourceLocation has very limited utility given the inflexible implementation.

Upvotes: 1

Caleb
Caleb

Reputation: 124997

This isn't the sort of thing you'd ever need as a beginner, and you could probably go through an entire career without using it. It seems to be meant for use in tools that generate source code. See the comments in the original feature proposal for the complete story.

TL/DR: Don't worry about it, you'll never need it.

Upvotes: 4

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