TOML Syntax Reference

A complete reference for TOML syntax supported by PHP Toml.

Comments

# This is a full-line comment
key = "value"  # This is an inline comment

Keys

Bare Keys

key = "value"
bare_key = "value"
bare-key = "value"
1234 = "value"

Bare keys may only contain ASCII letters, digits, underscores, and dashes.

Quoted Keys

"127.0.0.1" = "value"
"character encoding" = "value"
'key with single quotes' = "value"
"ʎǝʞ" = "value"  # Unicode allowed

Dotted Keys

# These are equivalent:
physical.color = "orange"

[physical]
color = "orange"

Dotted keys create nested tables:

fruit.apple.color = "red"
# Creates: { "fruit": { "apple": { "color": "red" } } }

Strings

Basic Strings

str = "I'm a string"
str_with_quote = "She said \"hello\""

Escape sequences:

Sequence	Character
\b	Backspace (U+0008)
\t	Tab (U+0009)
\n	Line feed (U+000A)
\f	Form feed (U+000C)
\r	Carriage return (U+000D)
\"	Quote (U+0022)
\\	Backslash (U+005C)
\e	Escape (U+001B) - TOML 1.1
\xHH	Unicode (U+00HH) - TOML 1.1
\uHHHH	Unicode (U+HHHH)
\UHHHHHHHH	Unicode (U+HHHHHHHH)

Multi-line Basic Strings

str = """
Roses are red
Violets are blue"""

Line-ending backslash trims whitespace:

str = """\
    The quick brown \
    fox jumps over \
    the lazy dog."""
# Result: "The quick brown fox jumps over the lazy dog."

Literal Strings

No escaping - what you see is what you get:

path = 'C:\Users\nodejs\templates'
regex = '<\i\c*\s*>'

Multi-line Literal Strings

regex = '''I [dw]on't need \d{2} apples'''

Numbers

Integers

int1 = +99
int2 = 42
int3 = 0
int4 = -17
int5 = 1_000_000     # Underscores for readability

Other bases:

hex = 0xDEADBEEF
oct = 0o755
bin = 0b11010110

Floats

flt1 = +1.0
flt2 = 3.1415
flt3 = -0.01
flt4 = 5e+22
flt5 = 1e06
flt6 = -2E-2
flt7 = 6.626e-34

Special values:

inf1 = inf      # Positive infinity
inf2 = +inf     # Positive infinity
inf3 = -inf     # Negative infinity
nan1 = nan      # Not a number
nan2 = +nan     # Not a number
nan3 = -nan     # Not a number

Booleans

bool1 = true
bool2 = false

Dates and Times

Offset Date-Time

odt1 = 1979-05-27T07:32:00Z
odt2 = 1979-05-27T00:32:00-07:00
odt3 = 1979-05-27T00:32:00.999999-07:00
odt4 = 1979-05-27 07:32:00Z  # Space separator (TOML 1.1)

Local Date-Time

ldt1 = 1979-05-27T07:32:00
ldt2 = 1979-05-27T00:32:00.999999

Local Date

ld1 = 1979-05-27

Local Time

lt1 = 07:32:00
lt2 = 07:32:00.999999
lt3 = 07:32           # Optional seconds (TOML 1.1)

Arrays

integers = [1, 2, 3]
colors = ["red", "yellow", "green"]
nested = [[1, 2], [3, 4, 5]]
mixed_types = ["string", 123, true]  # Mixed types allowed

# Multi-line
hosts = [
    "alpha",
    "beta",
    "gamma",  # Trailing comma allowed
]

Tables

Standard Tables

[table]
key1 = "value1"
key2 = "value2"

[table.subtable]
key = "value"

Inline Tables

point = { x = 1, y = 2 }
animal = { type.name = "pug" }

WARNING

Inline tables cannot be extended after definition:

# INVALID
point = { x = 1 }
point.y = 2  # Error!

Array of Tables

[[products]]
name = "Hammer"
price = 9.99

[[products]]
name = "Nail"
price = 0.05

[[products.reviews]]
author = "Alice"
rating = 5

[[products.reviews]]
author = "Bob"
rating = 4

Result:

[
    'products' => [
        [
            'name' => 'Hammer',
            'price' => 9.99,
        ],
        [
            'name' => 'Nail',
            'price' => 0.05,
            'reviews' => [
                ['author' => 'Alice', 'rating' => 5],
                ['author' => 'Bob', 'rating' => 4],
            ],
        ],
    ],
]

Super Tables

Define sub-tables before their parent:

[x.y.z.w]  # Creates implicit tables x, x.y, x.y.z

[x]  # Now define x explicitly
key = "value"

Key/Value Separation

Keys and values must be on the same line:

# Valid
key = "value"

# Invalid
key =
"value"