diff --git a/scanner/lexer.go b/scanner/lexer.go
index d63bc3d..7fa06bd 100644
--- a/scanner/lexer.go
+++ b/scanner/lexer.go
@@ -20,147 +20,285 @@ const (
 	classOther
 )
 
+// T_INCLUDE token
 const T_INCLUDE = 57346
+// T_INCLUDE_ONCE token
 const T_INCLUDE_ONCE = 57347
+// T_EXIT token
 const T_EXIT = 57348
+// T_IF token
 const T_IF = 57349
+// T_LNUMBER token
 const T_LNUMBER = 57350
+// T_DNUMBER token
 const T_DNUMBER = 57351
+// T_STRING token
 const T_STRING = 57352
+// T_STRING_VARNAME token
 const T_STRING_VARNAME = 57353
+// T_VARIABLE token
 const T_VARIABLE = 57354
+// T_NUM_STRING token
 const T_NUM_STRING = 57355
+// T_INLINE_HTML token
 const T_INLINE_HTML = 57356
+// T_CHARACTER token
 const T_CHARACTER = 57357
+// T_BAD_CHARACTER token
 const T_BAD_CHARACTER = 57358
+// T_ENCAPSED_AND_WHITESPACE token
 const T_ENCAPSED_AND_WHITESPACE = 57359
+// T_CONSTANT_ENCAPSED_STRING token
 const T_CONSTANT_ENCAPSED_STRING = 57360
+// T_ECHO token
 const T_ECHO = 57361
+// T_DO token
 const T_DO = 57362
+// T_WHILE token
 const T_WHILE = 57363
+// T_ENDWHILE token
 const T_ENDWHILE = 57364
+// T_FOR token
 const T_FOR = 57365
+// T_ENDFOR token
 const T_ENDFOR = 57366
+// T_FOREACH token
 const T_FOREACH = 57367
+// T_ENDFOREACH token
 const T_ENDFOREACH = 57368
+// T_DECLARE token
 const T_DECLARE = 57369
+// T_ENDDECLARE token
 const T_ENDDECLARE = 57370
+// T_AS token
 const T_AS = 57371
+// T_SWITCH token
 const T_SWITCH = 57372
+// T_ENDSWITCH token
 const T_ENDSWITCH = 57373
+// T_CASE token
 const T_CASE = 57374
+// T_DEFAULT token
 const T_DEFAULT = 57375
+// T_BREAK token
 const T_BREAK = 57376
+// T_CONTINUE token
 const T_CONTINUE = 57377
+// T_GOTO token
 const T_GOTO = 57378
+// T_FUNCTION token
 const T_FUNCTION = 57379
+// T_CONST token
 const T_CONST = 57380
+// T_RETURN token
 const T_RETURN = 57381
+// T_TRY token
 const T_TRY = 57382
+// T_CATCH token
 const T_CATCH = 57383
+// T_FINALLY token
 const T_FINALLY = 57384
+// T_THROW token
 const T_THROW = 57385
+// T_USE token
 const T_USE = 57386
+// T_INSTEADOF token
 const T_INSTEADOF = 57387
+// T_GLOBAL token
 const T_GLOBAL = 57388
+// T_VAR token
 const T_VAR = 57389
+// T_UNSET token
 const T_UNSET = 57390
+// T_ISSET token
 const T_ISSET = 57391
+// T_EMPTY token
 const T_EMPTY = 57392
+// T_HALT_COMPILER token
 const T_HALT_COMPILER = 57393
+// T_CLASS token
 const T_CLASS = 57394
+// T_TRAIT token
 const T_TRAIT = 57395
+// T_INTERFACE token
 const T_INTERFACE = 57396
+// T_EXTENDS token
 const T_EXTENDS = 57397
+// T_IMPLEMENTS token
 const T_IMPLEMENTS = 57398
+// T_OBJECT_OPERATOR token
 const T_OBJECT_OPERATOR = 57399
+// T_DOUBLE_ARROW token
 const T_DOUBLE_ARROW = 57400
+// T_LIST token
 const T_LIST = 57401
+// T_ARRAY token
 const T_ARRAY = 57402
+// T_CALLABLE token
 const T_CALLABLE = 57403
+// T_CLASS_C token
 const T_CLASS_C = 57404
+// T_TRAIT_C token
 const T_TRAIT_C = 57405
+// T_METHOD_C token
 const T_METHOD_C = 57406
+// T_FUNC_C token
 const T_FUNC_C = 57407
+// T_LINE token
 const T_LINE = 57408
+// T_FILE token
 const T_FILE = 57409
+// T_COMMENT token
 const T_COMMENT = 57410
+// T_DOC_COMMENT token
 const T_DOC_COMMENT = 57411
+// T_OPEN_TAG token
 const T_OPEN_TAG = 57412
+// T_OPEN_TAG_WITH_ECHO token
 const T_OPEN_TAG_WITH_ECHO = 57413
+// T_CLOSE_TAG token
 const T_CLOSE_TAG = 57414
+// T_WHITESPACE token
 const T_WHITESPACE = 57415
+// T_START_HEREDOC token
 const T_START_HEREDOC = 57416
+// T_END_HEREDOC token
 const T_END_HEREDOC = 57417
+// T_DOLLAR_OPEN_CURLY_BRACES token
 const T_DOLLAR_OPEN_CURLY_BRACES = 57418
+// T_CURLY_OPEN token
 const T_CURLY_OPEN = 57419
+// T_PAAMAYIM_NEKUDOTAYIM token
 const T_PAAMAYIM_NEKUDOTAYIM = 57420
+// T_NAMESPACE token
 const T_NAMESPACE = 57421
+// T_NS_C token
 const T_NS_C = 57422
+// T_DIR token
 const T_DIR = 57423
+// T_NS_SEPARATOR token
 const T_NS_SEPARATOR = 57424
+// T_ELLIPSIS token
 const T_ELLIPSIS = 57425
+// T_EVAL token
 const T_EVAL = 57426
+// T_REQUIRE token
 const T_REQUIRE = 57427
+// T_REQUIRE_ONCE token
 const T_REQUIRE_ONCE = 57428
+// T_LOGICAL_OR token
 const T_LOGICAL_OR = 57429
+// T_LOGICAL_XOR token
 const T_LOGICAL_XOR = 57430
+// T_LOGICAL_AND token
 const T_LOGICAL_AND = 57431
+// T_INSTANCEOF token
 const T_INSTANCEOF = 57432
+// T_NEW token
 const T_NEW = 57433
+// T_CLONE token
 const T_CLONE = 57434
+// T_ELSEIF token
 const T_ELSEIF = 57435
+// T_ELSE token
 const T_ELSE = 57436
+// T_ENDIF token
 const T_ENDIF = 57437
+// T_PRINT token
 const T_PRINT = 57438
+// T_YIELD token
 const T_YIELD = 57439
+// T_STATIC token
 const T_STATIC = 57440
+// T_ABSTRACT token
 const T_ABSTRACT = 57441
+// T_FINAL token
 const T_FINAL = 57442
+// T_PRIVATE token
 const T_PRIVATE = 57443
+// T_PROTECTED token
 const T_PROTECTED = 57444
+// T_PUBLIC token
 const T_PUBLIC = 57445
+// T_INC token
 const T_INC = 57446
+// T_DEC token
 const T_DEC = 57447
+// T_YIELD_FROM token
 const T_YIELD_FROM = 57448
+// T_INT_CAST token
 const T_INT_CAST = 57449
+// T_DOUBLE_CAST token
 const T_DOUBLE_CAST = 57450
+// T_STRING_CAST token
 const T_STRING_CAST = 57451
+// T_ARRAY_CAST token
 const T_ARRAY_CAST = 57452
+// T_OBJECT_CAST token
 const T_OBJECT_CAST = 57453
+// T_BOOL_CAST token
 const T_BOOL_CAST = 57454
+// T_UNSET_CAST token
 const T_UNSET_CAST = 57455
+// T_COALESCE token
 const T_COALESCE = 57456
+// T_SPACESHIP token
 const T_SPACESHIP = 57457
+// T_NOELSE token
 const T_NOELSE = 57458
+// T_PLUS_EQUAL token
 const T_PLUS_EQUAL = 57459
+// T_MINUS_EQUAL token
 const T_MINUS_EQUAL = 57460
+// T_MUL_EQUAL token
 const T_MUL_EQUAL = 57461
+// T_DIV_EQUAL token
 const T_DIV_EQUAL = 57462
+// T_CONCAT_EQUAL token
 const T_CONCAT_EQUAL = 57463
+// T_MOD_EQUAL token
 const T_MOD_EQUAL = 57464
+// T_AND_EQUAL token
 const T_AND_EQUAL = 57465
+// T_OR_EQUAL token
 const T_OR_EQUAL = 57466
+// T_XOR_EQUAL token
 const T_XOR_EQUAL = 57467
+// T_SL_EQUAL token
 const T_SL_EQUAL = 57468
+// T_SR_EQUAL token
 const T_SR_EQUAL = 57469
+// T_POW_EQUAL token
 const T_POW_EQUAL = 57470
+// T_BOOLEAN_OR token
 const T_BOOLEAN_OR = 57471
+// T_BOOLEAN_AND token
 const T_BOOLEAN_AND = 57472
+// T_IS_EQUAL token
 const T_IS_EQUAL = 57473
+// T_IS_NOT_EQUAL token
 const T_IS_NOT_EQUAL = 57474
+// T_IS_IDENTICAL token
 const T_IS_IDENTICAL = 57475
+// T_IS_NOT_IDENTICAL token
 const T_IS_NOT_IDENTICAL = 57476
+// T_IS_SMALLER_OR_EQUAL token
 const T_IS_SMALLER_OR_EQUAL = 57477
+// T_IS_GREATER_OR_EQUAL token
 const T_IS_GREATER_OR_EQUAL = 57478
+// T_SL token
 const T_SL = 57479
+// T_SR token
 const T_SR = 57480
+// T_POW token
 const T_POW = 57481
 
+// Lval parsers yySymType must implement this interface
 type Lval interface {
 	Token(tkn t.Token)
 }
 
+// Lexer
 type Lexer struct {
 	*lex.Lexer
 	StateStack    []int
@@ -168,6 +306,7 @@ type Lexer struct {
 	Comments      []comment.Comment
 }
 
+// Rune2Class returns the rune integer id
 func Rune2Class(r rune) int {
 	if r >= 0 && r < 0x80 { // Keep ASCII as it is.
 		return int(r)
@@ -185,6 +324,7 @@ func Rune2Class(r rune) int {
 	return -1
 }
 
+// NewLexer the Lexer constructor
 func NewLexer(src io.Reader, fName string) *Lexer {
 	file := token.NewFileSet().AddFile(fName, -1, 1<<31-1)
 	lx, err := lex.New(file, bufio.NewReader(src), lex.RuneClass(Rune2Class))