TOML Format

EegFun.jl uses TOML (Tom's Obvious Minimal Language) for its pipeline configuration files and epoch condition files. TOML is designed to be easy to read and write — if you can read an INI file, you already know most of what you need.

Key–Value Pairs

The most basic building block. Values can be strings, numbers, or booleans:

directory = "./preprocessed_files"
epoch_start = -0.2
apply = true

Strings use double quotes. Numbers and booleans (true / false) are unquoted.

Comments

Lines starting with # are comments and are ignored:

# High-pass filter settings
freq = 0.1   # cutoff in Hz

Tables (Sections)

Square brackets define a table (a group of related settings). Everything below a table header belongs to that table, until the next header:

[files.input]
directory = "."
layout_file = "biosemi72.csv"

[files.output]
directory = "./preprocessed_files"
save_ica_data = true

Dots create nested tables. The example above is equivalent to:

[files]

  [files.input]
  directory = "."

  [files.output]
  directory = "./preprocessed_files"

Arrays

Square brackets around values create arrays (lists):

raw_data_files = ["participant_01.bdf", "participant_02.bdf"]

Nested arrays are arrays of arrays:

# Each inner array lists alternative channel names (first match wins)
vEOG_channels = [["Fp1", "Fp2"], ["IO1", "IO2"], ["vEOG"]]

Arrays of Tables

Double square brackets [[...]] define an array of tables — a list of identically structured sections. This is how epoch conditions are specified:

[epochs]

[[epochs.conditions]]
name = "standard"
trigger_sequences = [[1]]
reference_index = 1

[[epochs.conditions]]
name = "deviant"
trigger_sequences = [[2]]
reference_index = 1

[[epochs.conditions]]
name = "novel"
trigger_sequences = [[3, 4]]
reference_index = 1
timing_pairs = [[1, 2]]
min_interval = 0.1
max_interval = 2.0

Each [[epochs.conditions]] block adds one entry to the conditions list inside the epochs table.

Quick Reference

Feature	Syntax	Example
String	"..."	"avg"
Integer	bare number	1
Float	decimal number	0.1
Boolean	true / false	true
Array	[...]	[1, 2, 3]
Table	[name]	[preprocess]
Nested table	[a.b]	[preprocess.eeg]
Array of tables	[[name]]	[[epochs.conditions]]
Comment	# ...	# cutoff in Hz

Further Reading

• TOML homepage — introduction and full language reference

• Pipeline configuration — using TOML with EegFun.jl's preprocessing pipeline