Stdlib and Built-ins

The complete standard library documentation now lives in the dedicated Stdlib section of this manual.

Start here:

• Stdlib Overview
• List Module
• Option Module
• Map Module
• String Module
• Int, Float, Bool Modules
• Stdlib Recipes

This page summarizes how stdlib and runtime externs differ.

Core built-in groups

• List.*
• Option.*
• Map.*
• String.*
• parsing helpers: Int.tryParse, Float.tryParse, Bool.tryParse
• scalar formatters: Int.toString, Float.toString, Bool.toString
• environment types/values: Environment, FsKind, Env

Runtime extern families

• Fs.* filesystem utilities
• Json.*
• Xml.*
• Regex.*
• hashing and GUID helpers

print

print "hello"

Use print for quick script output and debugging.

CLI environment

Env is not a runtime extern. It is a host-injected built-in value with the stdlib Environment type:

type Environment =
  { ScriptName: string option
    Arguments: string list }

Use Env.Arguments for script arguments and Env.ScriptName when a script needs to know whether it is running from a file or stdin/REPL.