1 Syntax
The following describers RAWK language syntax, how to write conditions and differences between RAWK and AWK.
1.1 Conditions
| condition | = | import-expression | ||
| | | begin-expression | |||
| | | end-expression | |||
| | | matchall-expression | |||
| | | match-expression | |||
| | | ... | |||
| import-expression | = | (~seq IMPORT import-body) | ||
| begin-expression | = | (~seq BEGIN expression-body) | ||
| end-expression | = | (~seq END expression-body) | ||
| matchall-expression | = | expression-body | ||
| match-expression | = | (~seq symbol-regexp expression-body) | ||
| import-body | = | (import-mod ...) | ||
| expression-body | = | (body ...) |
~seq means that the inside identifiers appear as a sequence and they are not surrounded by parentheses,
import-name and import-statement are identifiers referring to a identifier imported from a module and the module the identifier should be imported from,
symbol-regexp is a symbol treated as a regexp, for example .* will become #rx".*",
body is any racket expression.
1.2 RAWK vs AWK
condition actions (bodys) are pure Racket syntax
conditions are surrounded by "||" rather than "//",
In RAWK:
|a.*l| {
(print "!")
}
In AWK:
/a.*l/ {
print "!";
}
"||" is also optional, it encapsulates the symbol-regexp similarly to how it can encapsulate symbols in Racket, so if there are no characters that are specially treated in the symbol-regexp, then "||" can be omitted,
there is no function statement, custom functions used inside condition bodys should be instead defined inside BEGIN pseudo-condition,
BEGIN {
(define (smile)
(displayln ":-)"))
}
{
(smile)
}
IMPORT can be used to import Racket code defined elsewhere.