Class new title: Reader
	subclassof: Object
	fields: 'source collector token nextchar typetbl '
	declare: 'typetable '

classInit | t1 t2 t3 t4 t5  
	[typetable _ String new: 256.
	t1 _ Stream new of: (5 0 255 1 65 90 1 97 122 2 48 57 3 58 58 3 3 3 4 9 10 4 12 13 4 32 32 6 34 34 6 25 25 7 39 39 8 21 21 9 26 26 10 30 30 11 40 41 ).
	while [t2 _ t1 next.
	t2] do
		[t3 _ t1 next.
		t4 _ t1 next.
		for t5 from: (t3 + 1 to: t4 + 1) do
			[typetable  t5 _ t2]]]

of: t1 
	[typetbl _ typetable.
	token _ Stream default.
	source _ t1 asStream.
	self step]

rdint: t1 
	[token reset.
	[nextchar = t1 
		[token next_ t1.
		self step]].
	while nextchar do
		[nextchar < 48  [token contents]
		[nextchar > 57 
			[nextchar > 72  [token contents]
			nextchar < 65  [token contents]
			token next_ nextchar.
			nextchar _ source next]].
		token next_ nextchar.
		nextchar _ source next].
	token contents]

read 
	[self readInto: TokenCollector default]

readInto: t1 | t2 
	[collector _ t1.
	while nextchar do
		[t2 _ typetbl  (nextchar + 1).
		t2 = 4 
			[collector separator: nextchar.
			nextchar _ source next]
		t2 = 1  [self readatom: 0]
		t2 = 5 
			[collector onechar: nextchar.
			nextchar _ source next]
		t2 = 6 
			[self upto: nextchar  [collector notify: 'Unmatched comment quote']
			collector comment: token contents]
		t2 = 2  [self readnum]
		t2 = 11 
			[[nextchar = 40  [collector leftparen]
			collector rightparen].
			nextchar _ source next]
		t2 = 7 
			[self upto: nextchar  [collector notify: 'Unmatched string quote']
			collector string: token contents]
		t2 = 8  [self readnum]
		t2 = 9 
			[self upto: 13  [collector notify: '^Z without CR']
			collector trailer: token contents]
		t2 = 10  [collector contents]
		t2 = 3  [self readatom: 1]].
	collector contents]

readatom: t1 | t2 t3 t4 
	[token reset.
	while [token next_ nextchar.
	nextchar _ source next.
	nextchar and [t2 _ typetbl  (nextchar + 1).
	t2 
 3]] do
		[t2 = 3  [t1 _ t1 + 1]].
	t3 _ token contents.
	t1 = 0  [collector identifier: t3]
	t1 > 1  [collector otheratom: t3]
	t3 length = 1  [collector otheratom: t3]
	t4 _ t3  t3 length.
	t4 = 58  [collector keyword: t3]
	t4 = 3  [collector keyword: t3]
	collector otheratom: t3]

readnum | t1 t2 t3 
	[t1 _ self rdint: 21.
	nextchar = 46 
		[self step.
		nextchar  false or nextchar isdigit  false 
			[collector integer: t1.
			collector onechar: 46]
		t2 _ self rdint: 1.
		[nextchar = 101 
			[self step.
			t3 _ self rdint: 21]
		t3 _ ''].
		collector float: t1 fraction: t2 exp: t3]
	collector integer: t1]

step 
	[nextchar _ source next]

upto: t1 | t2 
	[t2 _ source position.
	token reset.
	while [nextchar _ source next.
	nextchar] do
		[[nextchar = t1 
			[self step.
			t1  39  [false]
			nextchar  39  [false]]].
		token next_ nextchar].
	source skip: t2 - 1 - source position.
	true]