GEDCOM parser example (basic)

gedcom-parser.red

Red [
	references: http://user.it.uu.se/~andersa/gedcom/ch1.html#grammar
	sample-files: [
		http://heiner-eichmann.de/gedcom/gedcom.htm
		http://heiner-eichmann.de/gedcom/allged.ged
	]
]

gedcom_main: [some gedcom_line]
gedcom_line: [
	level 			(print ['level =level])
	delim 			(print 'delim)
	opt_xref_id		(print ['xref_id =xref_id])
	tag 			(print ['tag =tag])
	opt_line_value	(print ['line_value =line_value])
	terminator		(print 'terminator)
]

alpha: charset [#"A" - #"Z" #"a" - #"z" #"_"]
alphanum: [alpha | digit]
any_char: [alpha | digit | otherchar | #"#" | space | "@@"]
delim: space
digit: charset [#"0" - #"9"]
escape: [ "@#" escape_text #"@" non_at]
escape_text: [copy =escape_text some any_char]
level: [copy =level some digit]	; (Do not use non-significant leading zeroes such as 02.)
line_item: [pointer | escape | any_char]
line_value: [copy =line_value some line_item]
non_at: [alpha | digit | otherchar | #"#" | space]
opt_line_value: [(=line_value: none) opt [delim line_value | delim]]
opt_xref_id: [(=xref_id: none) opt [pointer delim]]

otherchar: charset [
	#"^(21)" - #"^(22)"
	#"^(24)" - #"^(2F)"
	#"^(3A)" - #"^(3F)"
	#"^(5B)" - #"^(5E)"
	#"^(60)" 				; `
	#"^(7B)" - #"^(7E)"
	#"^(80)" - #"^(FF)"
]
; Any ASCII character except control characters (0x00 - 0x1F), alphanum, 
; space ( ), number sign (#), at character (@), and the DEL character (0x7F).

pointer: [#"@" pointer_string (=xref_id: =pointer_string) #"@"]
pointer_char: [non_at]
pointer_string: [copy =pointer_string [alphanum some pointer_char]]
tag: [copy =tag some alphanum]
terminator: [cr lf | lf cr | cr | lf]

;-------------------------------------------------------------------------------

sample: {0 HEAD
1 SOUR PAF
2 NAME Personal Ancestral File
2 VERS 5.0
1 DATE 30 NOV 2000
1 GEDC
2 VERS 5.5
2 FORM LINEAGE-LINKED
1 CHAR ANSEL
1 SUBM @U1@
0 @I1@ INDI
1 NAME John /Smith/
1 SEX M
1 FAMS @F1@
0 @I2@ INDI
1 NAME Elizabeth /Stansfield/
1 SEX F
1 FAMS @F1@
0 @I3@ INDI
1 NAME James /Smith/
1 SEX M
1 FAMC @F1@
0 @F1@ FAM
1 HUSB @I1@
1 WIFE @I2@
1 MARR
1 CHIL @I3@
0 @U1@ SUBM
1 NAME Submitter
0 TRLR
}

parse sample gedcom_main
parse read http://heiner-eichmann.de/gedcom/allged.ged gedcom_main