Config File Compatibility

SuperTOML's core strengths — typed key-value configs, dimensional context overrides, and cascading resolution — map naturally to many existing configuration formats in the Linux/macOS ecosystem. This page evaluates which common config files are good candidates for representation as SuperTOML.

Excellent Fit

These config files already use a cascading or override model that maps directly to SuperTOML's [default-configs] + [dimensions] + [[overrides]] structure.

SSH Config (~/.ssh/config)

SSH config already cascades — Host * sets defaults and specific Host blocks override them. This maps directly to SuperTOML with a host dimension.

Traditional format:

Host *
    ServerAliveInterval 60
    ServerAliveCountMax 3
    ForwardAgent no
    IdentityFile ~/.ssh/id_ed25519

Host github.com
    IdentityFile ~/.ssh/github_key
    User git

Host staging-server
    Port 2222
    User deploy
    ForwardAgent yes

As SuperTOML:

[dimensions]
host = { position = 1, schema = { type = "string" } }

[default-configs]
ServerAliveInterval = { value = 60, schema = { type = "integer", minimum = 0 } }
ServerAliveCountMax = { value = 3, schema = { type = "integer", minimum = 1 } }
ForwardAgent = { value = false, schema = { type = "boolean" } }
IdentityFile = { value = "~/.ssh/id_ed25519", schema = { type = "string" } }
Port = { value = 22, schema = { type = "integer", minimum = 1, maximum = 65535 } }
User = { value = "deploy", schema = { type = "string" } }

[[overrides]]
_context_ = { host = "github.com" }
IdentityFile = "~/.ssh/github_key"
User = "git"

[[overrides]]
_context_ = { host = "staging-server" }
Port = 2222
User = "deploy"
ForwardAgent = true

Benefits: Schema validation catches invalid port numbers, enforces type correctness, and provides IDE autocomplete via LSP.

EditorConfig (.editorconfig)

EditorConfig uses glob-based cascading (root defaults with file-type and path-pattern overrides). This maps to dimensions like filetype and file_path_pattern.

Traditional format:

root = true

[*]
indent_style = space
indent_size = 4
charset = utf-8

[*.md]
trim_trailing_whitespace = false

[*.{js,ts}]
indent_size = 2

[Makefile]
indent_style = tab

[lib/**.js]
indent_size = 4

As SuperTOML:

[dimensions]
filetype = { position = 1, schema = { type = "string", enum = ["md", "js", "ts", "py", "yml", "Makefile"] } }
file_path_pattern = { position = 2, schema = { type = "string" } }

[default-configs]
indent_style = { value = "space", schema = { type = "string", enum = ["space", "tab"] } }
indent_size = { value = 4, schema = { type = "integer", enum = [2, 4, 8] } }
charset = { value = "utf-8", schema = { type = "string", enum = ["utf-8", "latin1", "utf-16be"] } }
trim_trailing_whitespace = { value = true, schema = { type = "boolean" } }

[[overrides]]
_context_ = { filetype = "md" }
trim_trailing_whitespace = false

[[overrides]]
_context_ = { filetype = "js" }
indent_size = 2

[[overrides]]
_context_ = { filetype = "ts" }
indent_size = 2

[[overrides]]
_context_ = { filetype = "Makefile" }
indent_style = "tab"

[[overrides]]
_context_ = { file_path_pattern = "lib/**", filetype = "js" }
indent_size = 4

SSHD Config (/etc/ssh/sshd_config)

The Match User/Group/Host/Address blocks are literal dimensional overrides on top of global defaults.

As SuperTOML:

[dimensions]
user = { position = 2, schema = { type = "string" } }
group = { position = 3, schema = { type = "string" } }
address = { position = 1, schema = { type = "string" } }

[default-configs]
PermitRootLogin = { value = false, schema = { type = "boolean" } }
PasswordAuthentication = { value = false, schema = { type = "boolean" } }
MaxAuthTries = { value = 6, schema = { type = "integer", minimum = 1 } }

[[overrides]]
_context_ = { group = "admin" }
PermitRootLogin = true

[[overrides]]
_context_ = { address = "192.168.1.0/24" }
PasswordAuthentication = true

Git Config (~/.gitconfig)

Git config has sections with typed key-values and conditional includes (includeIf) that map to dimension overrides (e.g., by directory or remote_url).

As SuperTOML:

[dimensions]
directory = { position = 1, schema = { type = "string" } }

[default-configs]
user_name = { value = "Dev User", schema = { type = "string" } }
user_email = { value = "dev@personal.com", schema = { type = "string", format = "email" } }
core_autocrlf = { value = "input", schema = { type = "string", enum = ["true", "false", "input"] } }
pull_rebase = { value = true, schema = { type = "boolean" } }

[[overrides]]
_context_ = { directory = "~/work/" }
user_email = "dev@company.com"

Logrotate (/etc/logrotate.conf)

Global defaults with per-file override blocks. Dimensions: log_file. Values like rotate, size, and compress are all typed.

As SuperTOML:

[dimensions]
log_file = { position = 1, schema = { type = "string" } }

[default-configs]
rotate = { value = 4, schema = { type = "integer", minimum = 0 } }
frequency = { value = "weekly", schema = { type = "string", enum = ["daily", "weekly", "monthly"] } }
compress = { value = true, schema = { type = "boolean" } }
missingok = { value = false, schema = { type = "boolean" } }

[[overrides]]
_context_ = { log_file = "/var/log/nginx/*.log" }
rotate = 14
frequency = "daily"

[[overrides]]
_context_ = { log_file = "/var/log/syslog" }
rotate = 7
missingok = true

Nginx Config (nginx.conf)

The http → server → location hierarchy is a cascading model. Dimensions: server_name, location_path.

As SuperTOML:

[dimensions]
server_name = { position = 2, schema = { type = "string" } }
location_path = { position = 1, schema = { type = "string" } }

[default-configs]
root = { value = "/var/www/html", schema = { type = "string" } }
worker_connections = { value = 1024, schema = { type = "integer", minimum = 1 } }
keepalive_timeout = { value = 65, schema = { type = "integer", minimum = 0 } }
gzip = { value = true, schema = { type = "boolean" } }

[[overrides]]
_context_ = { server_name = "api.example.com" }
root = "/var/www/api"

[[overrides]]
_context_ = { server_name = "api.example.com", location_path = "/v2" }
keepalive_timeout = 120

Apache Config (httpd.conf)

<VirtualHost>, <Directory>, and <Location> blocks are context overrides following the same cascading model.

Good Fit

These config files are key-value based and benefit from schema validation, even if their override model is simpler.

Config File	Description	Dimensions
~/.npmrc / pip.conf	Package manager settings (registry, strict-ssl). Benefit is primarily schema validation.	project, environment
systemd unit files (.service, etc.)	INI-format key-values (ExecStart, Restart, User). Drop-in override directories already mimic cascading.	environment, hostname
/etc/sysctl.conf	Kernel parameters (net.ipv4.ip_forward = 1). Flat key-value.	environment, host_role
~/.tmux.conf	Terminal multiplexer options. Some commands are imperative, but option settings map well.	terminal_type, os
/etc/security/limits.conf	Resource limits with domain/type/item/value structure — semantically dimensional.	user, group, limit_type
Docker Compose	Service configs with typed values. The existing override file (docker-compose.override.yml) is essentially a manual cascade.	environment, profile
~/.Xresources	X11 resource settings. Wildcard/class matching is a crude cascade.	application, display
/etc/default/* (e.g., grub, locale)	Simple KEY=VALUE environment configs.	machine_role

Partial Fit

These can be represented but lose some expressiveness in the translation.

Config File	Limitation
/etc/fstab	Tabular format (device, mountpoint, fstype, options). Could model as array of objects, but not a natural "config with overrides" use case.
/etc/sudoers	Rule-based with complex syntax (user host=(runas) command). The permission model doesn't map cleanly to key-value + dimensions.
/etc/crontab	Schedule expressions are job definitions, not key-value configurations.
/etc/rsyslog.conf	Rule-based routing (facility.priority → action). More of a pipeline definition than configuration.

Poor Fit

These files are fundamentally imperative or scripting-based and cannot be meaningfully represented as declarative configuration.

Config File	Reason
~/.bashrc / ~/.zshrc	Shell scripts with conditionals, functions, and aliases — not declarative config.
~/.vimrc / init.lua	Scripting languages (VimL, Lua), not key-value configuration.
Makefile	Build recipes with targets and dependencies, not configuration.
/etc/iptables/rules.v4	Ordered rule chains where order matters — fundamentally imperative.

What SuperTOML Adds

Across all compatible config files, SuperTOML provides consistent benefits:

• Schema validation — Catches typos like Port = "yes" or indent_size = -1 at parse time
• Deterministic priority resolution — When multiple overrides match, the winner is unambiguous (unlike ad-hoc precedence rules in many formats)
• IDE support via LSP — Autocomplete, hover docs, and real-time validation for any config file represented as SuperTOML
• Unified format — One syntax and toolchain for all configuration, regardless of the target system