Identifiers follow the usual conventions: initial letter or underscore
followed by alphanumeric or underscore. Letters are the 26 English
letters, with upper and lower case distinct. (Examples reserve
initial capitals for types and constants.) Identifiers prefixed with
@ are reserved for functions provided by the runtime.
Characters other than 7 bit ASCII should only appear in comments or string constants. Variables can't be named smiley face.
Semicolons are never optional; they are required or not allowed. Newlines never substitute for semicolons.
Tab, newline, and carriage return serve equally as white space between tokens. FeatureScript does not care how much you indent bodies of conditionals. The optional auto-formatter will attempt to indent code following traditional rules.
Most of the usual C-style operator, expression, and grouping
characters are used. For example
+= is a valid token. Pre- and
post-increment and decrement operators (++ and --) are not supported.
(They complicate overloading and make ordering harder to understand.)
Strings are in single or double quotation marks. Use backslash to
escape a quotation mark of the same kind. A few backslash escapes are
r, with meaning as in C. Unicode
characters in string constants can be generated by
\u followed by 4
Numeric constants are decimal floating point numbers, e.g.
1.44, plus the special value
inf for infinity. Negated constants
are converted to negative constants.
FeatureScript has both C and C++ style comments,
than ignored as in TeX.
Unary operators are '-', '!', parentheses for grouping, and
 for box access.
Binary operators are
||. They have the usual meanings except
^ is used
for exponentiation and
for string concatenation. Special operators
 for container access,
is for type checking, and
for type conversion.
Assignment operators are
Programs may also contain
Other symbols, or sequences of symbols, are reserved.