FAQ¶

General¶

What is Rayforce?¶

Rayforce is a high-performance data processing engine with its own language called Rayfall.

What kind of language is Rayfall?¶

Rayfall is a functional programming language with: - Dynamic typing - First-class functions - Immutable data structures - Built-in support for tables and time-series data - Native support for parallel processing

Data Types¶

What are the basic data types?¶

Atoms: i64, f64, symbol, char, date, time, timestamp, guid
Vectors: Lists of atoms of the same type
Lists: Heterogeneous collections
Tables: Column-oriented data structures
Dictionaries: Key-value mappings

How are strings represented?¶

Strings are vectors of characters and must be created using lists, not vector literals:

;; Correct
(list "Hello" "World")

;; Incorrect
["Hello" "World"]  ;; Vectors can't contain strings

How are symbols different from strings?¶

Symbols are interned strings - they are stored only once in memory and comparison is very fast. They're ideal for categorical data like status codes, department names, etc.

;; Symbol vector (no quotes needed)
[pending active completed]

;; Symbol creation
'pending  ;; Quote creates a symbol

Tables and Queries¶

How do I create a table?¶

(table [name age score]  ;; Column names as symbols
       (list (list "Alice" "Bob")  ;; Strings in lists
             [25 30]               ;; Numbers in vectors
             [85 90]))

How do I query data?¶

Using the select function with a dictionary of parameters:

(select {name: name 
         avg_score: (avg score)
         from: students
         where: (> score 80)
         by: age})

Performance¶

How does Rayforce handle large datasets?¶

Column-oriented storage for efficient memory use
Automatic parallelization of operations
Memory-mapped files for large datasets
Optimized vector operations

What operations are parallelized?¶

Most vector operations and aggregations are automatically parallelized, including: - Mathematical operations - Comparisons - Aggregations (sum, avg, etc.) - Map/filter operations

Development¶

How do I handle errors?¶

Using the try function:

(try 
  (dangerous-operation)
  {e: (println "Error:" e)})

How do I profile code?¶

Using the timeit function:

(timeit (expensive-calculation))

How do I load external code?¶

Using the load function:

(load "mylib.rf")

Temporal Data¶

How are dates and times handled?¶

Dates: Days since epoch (1970.01.01)
Times: Milliseconds since midnight

Timestamps: Milliseconds since epoch

;; Current timestamp in local timezone
(timestamp 'local)

;; Parse date
(as 'date "2024.03.15")

What timezone handling is available?¶

Local timezone based on system settings
UTC timezone available for all temporal functions
Timezone conversion respects daylight savings

Memory Management¶

Is there garbage collection?¶

Yes, Rayforce includes automatic garbage collection. Manual collection can be triggered with:

(gc)

How do I check memory usage?¶

Using the memstat function:

(memstat)