; UGI Grammar v0: RFC 5234 ABNF
; Generated from ugi_registry_v0.json
;
; Compatible with abnf.dev/abnf2svg

; === Top-level ===

ugi-string = "ugi:" version "@" handle ":" field-list

version = 1*DIGIT ["/" 1*DIGIT]

; handle: alphanumeric, hyphens, underscores, dots
handle = 1*(ALPHA / DIGIT / %x2D / %x5F / %x2E)

field-list = field *("," field)

; === Field dispatch ===

field = field-a / field-b / field-c / field-d / field-e / field-f / field-g / field-h / field-i / field-j / field-k / field-l / field-m / field-o / field-p / field-q / field-r / field-s / field-t / field-v / field-w / field-x / field-y / field-z

; === Common rules ===

ODIGIT = %x30-37

paid = "$"

aspire = "+" ODIGIT

paid-aspire = paid [aspire]

modifier = paid-aspire / aspire

alternative = "/" ODIGIT

; custom sub-ID: ~ followed by 2+ alpha chars
custom-sub = "~" 2*ALPHA

; sub-ID: 1-4 alpha chars
sub-id = 1*4ALPHA

; === Per-field rules ===

; a: Age (direct)
field-a = %x61 ODIGIT

; b: Build (special)
field-b = %x62 ODIGIT [aspire] "/" ODIGIT [aspire]

; c: Clothing (direct)
field-c = %x63 ODIGIT [alternative / aspire]

; d: Editor / IDE (multi)
field-d-entry = (sub-id / custom-sub) ODIGIT [aspire]
field-d = %x64 1*field-d-entry

; e: Education (direct)
field-e = %x65 ODIGIT [aspire]

; f: Food / Cooking (direct)
field-f = %x66 ODIGIT [modifier]

; g: Geek Specialization (special)
g-domain = 2*4ALPHA ["$"]
g-custom = "~" 2*ALPHA
field-g = %x67 (g-domain / g-custom) *("/" (g-domain / g-custom))

; h: Hair (multi)
field-h-entry = (sub-id / custom-sub) ODIGIT [aspire]
field-h = %x68 1*field-h-entry

; i: AI Stance (direct)
field-i = %x69 ODIGIT

; j: Gaming (multi)
field-j-entry = (sub-id / custom-sub) ODIGIT [modifier]
field-j = %x6A 1*field-j-entry

; k: Books (direct)
field-k = %x6B ODIGIT [aspire]

; l: Spoken Languages (multi)
field-l-entry = 2ALPHA ODIGIT [modifier]
field-l = %x6C 1*field-l-entry

; m: Music (multi)
field-m-entry = (sub-id / custom-sub) ODIGIT
field-m = %x6D 1*field-m-entry

; o: Operating System (multi)
field-o-entry = (sub-id / custom-sub) ODIGIT [modifier]
field-o = %x6F 1*field-o-entry

; p: Programming Languages (multi)
field-p-entry = (sub-id / custom-sub) ODIGIT [modifier]
field-p = %x70 1*field-p-entry

; q: Security / Hacking (direct)
field-q = %x71 ODIGIT [alternative / modifier]

; r: Religion (single)
field-r = %x72 (sub-id / custom-sub) ODIGIT

; s: Sex / Relationships (direct)
field-s = %x73 ODIGIT [alternative / aspire]

; t: TV / Film (multi)
field-t-entry = (sub-id / custom-sub) ODIGIT
field-t = %x74 1*field-t-entry

; v: Politics (special)
field-v = %x76 ODIGIT "/" ODIGIT

; w: Hardware (direct)
field-w = %x77 ODIGIT [modifier]

; x: Comics / Manga (multi)
field-x-entry = (sub-id / custom-sub) ODIGIT
field-x = %x78 1*field-x-entry

; y: Fitness (direct)
field-y = %x79 ODIGIT [modifier]

; z: Maker / DIY (direct)
field-z = %x7A ODIGIT [modifier]

; === Block format ===

ugi-block = block-header CRLF block-first-line CRLF 1*(block-field-line CRLF) block-footer

block-header = "------- BEGIN UGI BLOCK -------"
block-footer = "-------- END UGI BLOCK --------"

block-first-line = "v:" version SP "@" handle [SP block-geek-field]

; In block format, G field uses uppercase and appears on first line
block-geek-field = "G" (g-domain / g-custom) *("/" (g-domain / g-custom))

block-field-line = block-field *(SP block-field)

; Block fields use uppercase code prefix repeated per sub-ID
block-field = ALPHA 1*(ALPHA / DIGIT / %x24 / %x2B / %x2F / %x7E)

; === Core rules (RFC 5234) ===

ALPHA = %x41-5A / %x61-7A
DIGIT = %x30-39
SP = %x20
CRLF = %x0D.0A / %x0A