. The Lexical Elements of Pascal
. Useful meta-linguistic Macros
L::= (_) #(comma (_)).
N::= (_) #( (_) ).
O::= ( (_)|).
P::= O( left L( (_) ) right).
R::= (_) doubledot (_).
S::= (_) #(semicolon (_)).
. Lexemes in Pascal
adding_operator::= "+" | "-" | "or",
apostrophe_image::= "'""'",
array::="array",
begin::="begin",
caret::="^",
case::="case",
character_string::= "'" string_element #(string_element) "'",
colon::=":",
colon_equals::=":=",
comma::=",",
const::="const",
digit::= ("1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" | "0"),
digit_sequence::= digit #(digit),
do::="do",
dot::=".",
doubledot::="..",
downto::="downto",
else::="else",
end::="end",
equals::="=",
for::="for",
fractional_part::= digit_sequence,
function::="function",
goto::="goto",
identifier::= letter #( letter | digit),
if::="if",
label::="label",
left::="(",
left_br::="[",
letter::= ("a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z"),
multiplying_operator::= "*" | "/" | "div" | "mod" | "and",
nil::="nil",
not::="not",
of::="of",
of::="of",
packed::="packed",
packed::="packed",
procedure::="procedure",
program::="program",
record::="record",
relational_operator::= "=" | "<>" | "<" | ">" | "<=" | ">=" | "in",
repeat::="repeat",
right::=")",
right_br::="]",
scale_factor::= signed_integer,
semicolon::=";",
file::="file",
set::="set",
sign::= "+" | "-",
signed_integer::= O(sign) unsigned_integer,
string_character::= one_of_a_set_of_implementation_defined_characters,
string_element::= apostrophe_image | string_character,
then::="then",
to::="to",
type::="type",
unsigned_integer::= digit_sequence,
unsigned_real::= unsigned_integer "." fractional_part #("e" scale_factor |) | unsigned_integer "e" scale_factor,
until::="until",
var::="var",
var::="var",
while::="while",
with::="with",