Quotations

FSharp.Interop.Dynamic.SymbolicString turns an F# quotation into a member name (or a LeafInfo with name, return type, and declaring type). Use it when you want the compiler to check that Length exists rather than shipping a magic string.

open FSharp.Interop.Dynamic.SymbolicString

Symbol.nameOf(String.length)     // "length"
Symbol.nameOf(fun (x:string) -> x.ToString)  // "ToString"
Symbol.nameOf(Option.Some)       // "Some"

Symbol.typeOf is the same walk, returning the Type. Symbol.leafInfoOf returns both plus DeclaringType.

The argument is [<ReflectedDefinition>], so you write an expression, not Expr.Value. The library walks:

• named values
• union cases
• property / field gets
• method calls
• fun and let wrappers around those

Anything else (1, (1, 2), if … then …) throws ArgumentException.

sym<'T> exists only so you can quote a typed hole. Do not call it. Evaluating it throws.