{	scopeName = 'source.scheme';
	comment = '
		The foldings do not currently work the way I want them to. This
		may be a limitation of the way they are applied rather than the
		regexps in use. Nonetheless, the foldings will end on the last
		identically indented blank line following an s-expression. Not
		ideal perhaps, but it works. Also, the #illegal pattern never
		matches an unpaired ( as being illegal. Why?! -- Rob Rix

		This grammar still needs a bit of work, but I have tried to separate
		out disparate parts a bit. -- Jacob Rus
	';
	fileTypes = ( 'scm', 'sch' );
	foldingStartMarker = '(?x)^ [ \t]* \(
	  (?<par>
	    ( [^()\n]++ | \( \g<par> \)? )*+
	  )
	$';
	foldingStopMarker = '(?x)^ [ \t]*
	  (?<par>
	    ( [^()\n]++ | \( \g<par> \) )*+
	  )
	  ( \) [ \t]*+ ) ++
	$';
	patterns = (
		{	include = '#comment'; },
		{	include = '#sexp'; },
		{ 	include = '#string'; },
		{ 	include = '#language-functions'; },
		{ 	include = '#quote'; },
		{	include = '#illegal'; },
	);
	repository =
	{	comment =
		{	name = 'comment.line.semicolon.scheme';
			match = '(;).*$\n?';
			captures = { 1 = { name = 'punctuation.definition.comment.semicolon.scheme'; }; };
		};
		illegal =
		{	name = 'invalid.illegal.parenthesis.scheme';
			match = '[()]';
		};
		string = {
			name = 'string.quoted.double.scheme';
			begin = '(")';
			end = '(")';
			beginCaptures = { 1 = { name = 'punctuation.definition.string.begin.scheme'; }; };
			endCaptures = { 1 = { name = 'punctuation.definition.string.end.scheme'; }; };
			patterns = (
				{	name = 'constant.character.escape.scheme';
					match = '\\.';
				}
			);
		};
		language-functions = {
			patterns = (
				{	name = 'keyword.control.scheme';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( do|or|and|else|quasiquote|begin|if|case|set!|
						  cond|let|unquote|define|let\*|unquote-splicing|delay|
						  letrec)
						(?=(\s|\())';
				},
				{	name = 'support.function.boolean-test.scheme';
					comment = '
						These functions run a test, and return a boolean
						answer.
					';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( char-alphabetic|char-lower-case|char-numeric|
						  char-ready|char-upper-case|char-whitespace|
						  (?:char|string)(?:-ci)?(?:=|<=?|>=?)|
						  atom|boolean|bound-identifier=|char|complex|
						  identifier|integer|symbol|free-identifier=|inexact|
						  eof-object|exact|list|(?:input|output)-port|pair|
						  real|rational|zero|vector|negative|odd|null|string|
						  eq|equal|eqv|even|number|positive|procedure
						)
						(\?)		# name ends with ? sign
						(?=(\s|\()) # followed by space or (
					';
				},
				{	name = 'support.function.convert-type.scheme';
					comment = '
						These functions change one type into another.
					';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( char->integer|exact->inexact|inexact->exact|
						  integer->char|symbol->string|list->vector|
						  list->string|identifier->symbol|vector->list|
						  string->list|string->number|string->symbol|
						  number->string
						)
						(?=(\s|\()) # followed by space or (
					';
				},
				{	name = 'support.function.with-side-effects.scheme';
					comment = '
						These functions are potentially dangerous because
						they have side-effects which could affect other
						parts of the program.
					';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( set-(?:car|cdr)|				 # set car/cdr
						  (?:vector|string)-(?:fill|set) # fill/set string/vector
						)
						(!)			# name ends with ! sign
						(?=(\s|\()) # followed by space or (
					';
				},
				{	name = 'support.function.arithmetic-operators.scheme';
					comment = '
						+, -, *, /, =, >, etc.
					';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( >=?|<=?|=|[*/+-])
						(?=(\s|\()) # followed by space or (
						';
				},
				{	name = 'support.function.general.scheme';
					match = '(?x)
						(?<=(\s|\()) # preceded by space or (
						( append|apply|approximate|
						  call-with-current-continuation|call/cc|catch|
						  construct-identifier|define-syntax|display|foo|
						  for-each|force|cd|gen-counter|gen-loser|
						  generate-identifier|last-pair|length|let-syntax|
						  letrec-syntax|list|list-ref|list-tail|load|log|
						  macro|magnitude|map|map-streams|max|member|memq|
						  memv|min|newline|nil|not|peek-char|rationalize|
						  read|read-char|return|reverse|sequence|substring|
						  syntax|syntax-rules|transcript-off|transcript-on|
						  truncate|unwrap-syntax|values-list|write|write-char|

						  # cons, car, cdr, etc
						  cons|c(a|d){1,4}r|

						  # unary math operators
						  abs|acos|angle|asin|assoc|assq|assv|atan|ceiling|
						  cos|floor|round|sin|sqrt|tan|
						  (?:real|imag)-part|numerator|denominator

						  # other math operators
						  modulo|exp|expt|remainder|quotient|lcm|

						  # ports / files
						  call-with-(?:input|output)-file|
						  (?:close|current)-(?:input|output)-port|
						  with-(?:input|output)-from-file|
						  open-(?:input|output)-file|

						  # char-«foo»
						  char-(?:downcase|upcase|ready)|

						  # make-«foo»
						  make-(?:polar|promise|rectangular|string|vector)

						  # string-«foo», vector-«foo»
						  string(?:-(?:append|copy|length|ref))?|
						  vector(?:-length|-ref)
						)
						(?=(\s|\()) # followed by space or (
					';
				},
			);
		};
		constants = {
			patterns = (
				{	name = 'constant.language.boolean.scheme';
					match = '#[t|f]';
				},
				{	name = 'constant.other.symbol.scheme';
					match = "(')[[:alnum:]][[:alnum:]!$%&*+-./:<=>?@^_~]*";
					captures = { 1 = { name = 'punctuation.definition.symbol.scheme'; }; };
				},
				{	name = 'constant.numeric.scheme';
					match = '(?<=[\(\s])(#e|#i)?[0-9][0-9.]*';
				},
				{	name = 'constant.numeric.scheme';
					match = '(?<=[\(\s])(#x)[0-9a-fA-F]+';
				},
				{	name = 'constant.numeric.scheme';
					match = '(?<=[\(\s])(#o)[0-7]+';
				},
				{	name = 'constant.numeric.scheme';
					match = '(?<=[\(\s])(#b)[01]+';
				},
			);
		};
		quote = {
			comment = '
				We need to be able to quote any kind of item, which creates
				a tiny bit of complexity in our grammar.  It is hopefully
				not overwhelming complexity
			';
			patterns = (
				{	contentName = 'string.other.quoted-object.scheme';
					comment = 'quoted double-quoted string';
					begin = '('')\s*(?=")';
					end = '(?<=")';
					beginCaptures = {
						1 = { name = 'punctuation.section.quoted-code.scheme'; };
					};
					patterns = (
						{ include = '#quoted'; },
					);
				},
				{	contentName = 'string.other.quoted-object.scheme';
					comment = 'quoted s-expression';
					begin = '('')\s*(?=\()';
					end = '(?<=\))';
					beginCaptures = {
						1 = { name = 'punctuation.section.quoted-code.scheme'; };
					};
					patterns = (
						{ include = '#quoted'; },
					);
				},
				{	contentName = 'string.other.quoted-object.scheme';
					comment = 'quoted anything else';
					begin = '('')\s*(?=[^\s])';
					end = '(?<=\s)';
					beginCaptures = {
						1 = { name = 'punctuation.section.quoted-code.scheme'; };
					};
					patterns = (
						{ include = '#quoted'; },
					);
				},
				{	begin = '(?<=\()\s*(quote)\b\s*';
					end = '(?=\)|[ ])';
					beginCaptures = {
						1 = { name = 'keyword.control.quote.scheme'; };
					};
					patterns = (
						{	name = 'string.other.quoted-code.scheme';
							comment = 'quoted s-expression';
							begin = '(?=\()';
							end = '(?<=\))';
							patterns = (
								{ include = '#quoted'; },
							);
						},
						{	name = 'string.other.quoted-code.scheme';
							comment = 'quoted string';
							begin = '(?=")';
							end = '(?<=")';
							patterns = (
								{ include = '#quoted'; },
							);
						},
						{	name = 'string.other.quoted-code.scheme';
							comment = 'quoted anything else';
							match = '[^\s()"]+';
						},
					);
				}
			);
		};
		quoted = {
			patterns = (
				{ 	include = '#string'; },
				{	name = 'meta.expression.scheme';
					begin = '(\()';
					end = '(\))(\n)?';
					beginCaptures = { 1 = { name = 'punctuation.section.expression.begin.scheme'; }; };
					endCaptures =
					{	1 = { name = 'punctuation.section.expression.end.scheme'; };
						2 = { name = 'meta.after-expression.scheme'; };
					};
					patterns = (
						{ include = '#quoted'; },
					);
				},
				{ include = '#quote'; },
				{ include = '#illegal'; },
			);
		};
		sexp =
		{	name = 'meta.expression.scheme';
			begin = '(\()';
			end = '(\))(\n)?';
			beginCaptures = { 1 = { name = 'punctuation.section.expression.begin.scheme'; }; };
			endCaptures =
			{	1 = { name = 'punctuation.section.expression.end.scheme'; };
				2 = { name = 'meta.after-expression.scheme'; };
			};
			patterns = (
				{	include = '#comment'; },
				{	name = 'meta.declaration.procedure.scheme';
					begin = '(?x)
						(?<=\()       # preceded by (
						(define)\s+   # define
						\(            # list of parameters
						  ([[:alnum:]][[:alnum:]!$%&*+-./:<=>?@^_~]*)
						  ((\s+
						    ([[:alnum:]][[:alnum:]!$%&*+-./:<=>?@^_~]*|[._])
						   )*
						  )\s*
						\)
					';
					end = '(?=\))';
					captures =
					{	1 = { name = 'keyword.other.scheme'; };
						2 = { name = 'entity.name.function.scheme'; };
						3 = { name = 'variable.parameter.function.scheme'; };
					};
					patterns = (
						{	include = '#comment'; },
						{	include = '#sexp'; },
						{	include = '#illegal'; },
					);
				},
				{	name = 'meta.declaration.procedure.scheme';
					comment = '
						Not sure this one is quite correct.  That \s* is
						particularly troubling
					';
					begin = '(?x)
						(?<=\() # preceded by (
						(lambda)\s+
						(\() # opening paren
						((?:
						  ([[:alnum:]][[:alnum:]!$%&*+-./:<=>?@^_~]*|[._])
						  \s*
						)*)
						(\)) # closing paren
					';
					end = '(?=\))';
					captures =
					{	1 = { name = 'keyword.other.scheme'; };
						2 = { name = 'variable.parameter.scheme'; };
					};
					patterns = (
						{	include = '#comment'; },
						{	include = '#sexp'; },
						{	include = '#illegal'; },
					);
				},
				{	name = 'meta.declaration.variable.scheme';
					begin = '(?<=\()(define)\s([[:alnum:]][[:alnum:]!$%&*+-./:<=>?@^_~]*)\s*.*?';
					end = '(?=\))';
					captures =
					{	1 = { name = 'keyword.other.scheme'; };
						2 = { name = 'variable.language.scheme'; };
					};
					patterns = (
						{	include = '#comment'; },
						{	include = '#sexp'; },
						{	include = '#illegal'; },
					);
				},
				{	include = '#quote'; },
				{	include = '#language-functions'; },
				{	include = '#string'; },
				{	include = '#constants'; },
				{	name = 'constant.character.escape.scheme';
					match = '(?<=[\(\s])(#\\).';
				},
				{	include = '#sexp'; },
				{	include = '#illegal'; },
			);
		};
	};
}