birch/formatter

Log formatting utilities.

Formatters transform LogRecords into strings for output.

Types

Formatter

A formatter is a function that converts a LogRecord to a string.

pub type Formatter =
  fn(record.LogRecord) -> String

Values

format_metadata

</>

pub fn format_metadata(
  metadata: List(#(String, String)),
) -> String

Format metadata as key=value pairs separated by spaces.

format_metadata_colored

</>

pub fn format_metadata_colored(
  metadata: List(#(String, String)),
  use_color: Bool,
) -> String

Format metadata with color support. Each key gets a unique hash-based color when use_color is True.

format_metadata_visible

</>

pub fn format_metadata_visible(
  metadata: List(#(String, String)),
) -> String

Format metadata, excluding internal keys (prefixed with _). Internal keys are used by the logging system for features like semantic log styles and grouping, and should not be shown to users.

format_metadata_with_bold

</>

pub fn format_metadata_with_bold(
  metadata: List(#(String, String)),
  highlight_keys: List(String),
  use_color: Bool,
) -> String

Format metadata with specific keys highlighted. All keys get a unique hash-based color. Keys in the highlight_keys list are additionally styled with bold for extra visual distinction.

human_readable

</>

pub fn human_readable(record: record.LogRecord) -> String

Format a log record in a human-readable format.

Output format:

2024-12-26T10:30:45.123Z | INFO  | myapp.http | Request complete | key=value

pad_level

</>

pub fn pad_level(level_str: String) -> String

Pad a level string to 5 characters for alignment. Uses pattern matching on known log level strings for efficiency.

simple

</>

pub fn simple(record: record.LogRecord) -> String

Format a log record as a simple message with level prefix.

Output format:

[INFO] Request complete