- In what follows, the symbols
ID
,
INTEGER
,
FLOATING
POINT
,
BOOLEAN
, and
STRING
refer to the terms identifier and
integer, floating point number, Boolean, and
string constants,
which have been specified above.
Any other symbol in capital letters is explained in the grammar.
- A statement enclosed in double quotes is an extra-grammatical explanation.
- Spaces are not allowed within any of the character pairs
listed in the section on Characters and Keywords,
nor within an
ID
,
INTEGER
constant,
FLOATING
POINT
constant, or keyword.
Spaces are required between keywords,
ID
s,
INTEGER
constants,
and
FLOATING
POINT
constants.
- ISETL treats carriage returns and tabs as spaces.
Any input can be spread across lines without changing the meaning,
and ISETL will not
consider it to be complete until a semicolon ``
;
'' is entered.
The only exceptions to this are the
!include
input,
which is ended with a carriage return,
and the fact that a quoted string cannot be typed on more than one line.