ghci:tldr:6ac89
ghci: Start a REPL and load the specified Haskell source file.
$ ghci ${source_file-hs}
try on your machine
The command "ghci" is the acronym for "Glasgow Haskell Compiler Interactive." It launches the interactive mode of the GHCi compiler for Haskell, which allows you to execute Haskell code interactively and get immediate feedback.
The "${source_file-hs}" part of the command is a shell variable substitution. It means that if the variable "source_file" is defined, it will use its value as the source file for GHCi. If the variable is not defined, it will default to using "hs" as the source file.
In summary, this command starts an interactive session with the GHCi Haskell compiler, using the specified source file (or the default "hs" extension) for evaluation and interaction.
This explanation was created by an AI. In most cases those are correct. But please always be careful and
never run a command you are not sure if it is safe.