#NyaCSV

Parse CSV files in MoonBit with a small, focused API.

#Features

• Multiple input sources: parse CSV from String, Buffer, or Bytes.
• Configurable parsing: set delimiter, quote character, whitespace trimming, empty-line handling, and multiline quoted fields.
• Header handling: use the first row as headers or generate column names.
• Simple accessors: read headers, rows, and shape through public methods.
• Formatted output: render a table through the Show implementation.

#Quick Start

///|
test "readme/quick_start" {
  let data =
    #|Name,Age,Favorite Toy
    #|Mittens,3,Ball of yarn
    #|Whiskers,5,Laser pointer
    #|
  let csv = CSV::parse_string(data)
  let (rows, columns) = csv.shape()
  assert_eq(rows, 2)
  assert_eq(columns, 3)
  assert_eq(csv.header()[0], "Name")
  assert_eq(csv.header()[2], "Favorite Toy")
  assert_eq(csv.data()[0][0], "Mittens")
  assert_eq(csv.data()[1][2], "Laser pointer")
}

#Installation

#Usage Examples

#Parsing CSV with Custom Options

///|
test "readme/custom_options" {
  let data =
    #|Name;Description;Adopted
    #|Simba;"Playful orange tabby
    #|Loves treats";Yes
    #|
  let csv = CSV::parse_string(data, options={
    delimiter: ';',
    allow_newlines_in_quotes: true,
    quote_char: '"',
    skip_empty_lines: true,
    trim_spaces: true,
  })
  assert_eq(csv.header()[0], "Name")
  assert_eq(csv.header()[1], "Description")
  assert_eq(csv.data()[0][0], "Simba")
  let description =
    #|Playful orange tabby
    #|Loves treats
  assert_eq(csv.data()[0][1], description)
  assert_eq(csv.data()[0][2], "Yes")
}

#Creating CSV Data

///|
test "readme/create_from_array" {
  let data : Array[Array[String]] = [
    ["Name", "Age"],
    ["Luna", "2"],
    ["Oliver", "1"],
  ]
  let csv = CSV::from_array(data)
  assert_eq(csv.header().length(), 2)
  assert_eq(csv.data().length(), 2)
  assert_eq(csv.header()[0], "Name")
  assert_eq(csv.data()[0][0], "Luna")
  let expected =
    #|Name,Age
    #|Luna,2
    #|Oliver,1
    #|
  assert_eq(csv.to_string(), expected)
}

#Working with 2D Arrays

///|
test "readme/array_input" {
  let shelter_data : Array[Array[String]] = [
    ["Name", "Age", "Color", "Adopted"],
    ["Luna", "2", "Black", "Yes"],
    ["Oliver", "1", "Tabby", "No"],
    ["Bella", "4", "Calico", "Yes"],
  ]
  let csv = CSV::from_array(shelter_data)
  let (rows, columns) = csv.shape()
  assert_eq(rows, 3)
  assert_eq(columns, 4)
  assert_eq(csv.data()[2][0], "Bella")
  assert_eq(csv.data()[2][3], "Yes")
}

#Generated Headers

///|
test "readme/generated_headers" {
  let data : Array[Array[String]] = [
    ["Alice", "30", "Wonderland"],
    ["Bob", "25", "Builderland"],
  ]
  let csv = CSV::from_array(data, has_header=false, generate_headers=true)
  assert_eq(csv.header()[0], "column1")
  assert_eq(csv.header()[1], "column2")
  assert_eq(csv.header()[2], "column3")
  assert_eq(csv.data()[1][0], "Bob")
}

#API Reference

#CSV

#CSVOptions

• delimiter : Char
• allow_newlines_in_quotes : Bool
• quote_char : Char
• skip_empty_lines : Bool
• trim_spaces : Bool

#Parsing Methods

• CSV::parse_string(data : String, options? : CSVOptions) -> CSV
• CSV::parse_buffer(data : Buffer, options? : CSVOptions) -> CSV
• CSV::parse_bytes(data : Bytes, options? : CSVOptions) -> CSV

#Creation Methods

• CSV::new() -> CSV
• CSV::from_array(data : Array[Array[String]], has_header? : Bool, generate_headers? : Bool) -> CSV

#Advanced Examples

#Formatted Table Output

///|
test "readme/formatted_table_output" {
  let data =
    #|Breed,Origin,Size,Temperament
    #|Siamese,Thailand,Medium,"Vocal, Active"
    #|Maine Coon,USA,Large,"Gentle, Playful"
    #|Ragdoll,USA,Large,"Calm, Affectionate"
    #|
  let csv = CSV::parse_string(data)
  let logger = @buffer.new()
  csv.output(logger)
  let table = logger.contents().to_unchecked_string()
  assert_true(table.contains("Breed"))
  assert_true(table.contains("Maine Coon"))
  assert_true(table.contains("Gentle, Playful"))
}

#Handling Multiline Fields

///|
test "readme/multiline_fields" {
  let data =
    #|Name,Bio
    #|Lucy,"Lucy is curious.
    #|She loves exploring."
    #|Max,"Max is quiet.
    #|He sleeps often."
    #|
  let csv = CSV::parse_string(data)
  assert_eq(csv.header()[1], "Bio")
  let lucy_bio =
    #|Lucy is curious.
    #|She loves exploring.
  let max_bio =
    #|Max is quiet.
    #|He sleeps often.
  assert_eq(csv.data()[0][1], lucy_bio)
  assert_eq(csv.data()[1][1], max_bio)
}

#Contribution

#License