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Input Scanning

The scanner is the internal system in Stricli that processes user inputs from the command line and determines which route/command to run and the arguments to run it with. Configuration for this system is controlled by the scanner property in the application configuration.

Scanner Case Style​

As route, command, and flag names are all defined in the specification as object properties, it is likely that stylistic preferences will force these properties to adhere to camelCase styling. However, many CLI applications also support or require kebab-case style for naming at runtime. The caseStyle configuration allows you to adjust what to accept as input.

The default value for this configuration is original, which requires that any input match the defined name exactly. The other option is allow-kebab-for-camel, which augments the scanner and additionally allows the kebab-case style version of any camelCase style name. The conversion relies on converting upper case letters to lower case with a preceding -.

Argument Escape Sequence​

Stricli scans the user input to determine how to parse that input into flags and positional arguments. Due to the fact that every input string with a leading - is treated as a potential flag, it can be useful to bypass this behavior in some circumstances. The user can specify -- which indicates to the scanner that any following inputs should be treated as positional arguments. This feature is controlled by the allowArgumentEscapeSequence property, which defaults to false.

The following is an example command that prints flags and args to stdout.

With allowArgumentEscapeSequence=false

run --foo -- --bar
{ foo: true, bar: true }, ["--"]

With allowArgumentEscapeSequence=true

run --foo -- --bar
{ foo: true }, ["--bar"]

Distance Calculation​

When input scanning fails to find a route/command or flag, Stricli will include suggested alternatives in the error message ("did you mean ___?"). Stricli calculates the Damerau-Levenshtein distance of all potential alternatives and returns only those that have a distance below a certain threshold. By default, this distance threshold is 7 with specific weights for certain operations (insertion=1, deletion=2, substitution=2, transposition=0). However, it can be customized to any value by editing the distanceOptions property.