suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

clarify define-extended-language example

Browse Source
This commit is contained in:
Burke Fetscher 2012-08-01 10:09:45 -05:00
parent 2032aaf341
commit db437e0ba8
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
collects/redex/scribblings/ref.scrbl
View File

@ -657,15 +657,15 @@ extended non-terminals. For example, this language:
(define-extended-language lc-num-lang
lc-lang
(v .... (code:comment "extend the previous `v' non-terminal")
+
number)
number
+)
(x (variable-except λ +)))
]
extends lc-lang with two new alternatives for the @racket[v]
non-terminal, carries forward the @racket[e] and @racket[c]
non-terminals, and replaces the @racket[x] non-terminal with a
new one (which happens to be equivalent to the one that would
extends lc-lang with two new alternatives (@racket[+] and @racket[number])
for the @racket[v] non-terminal, carries forward the @racket[e]
and @racket[c] non-terminals, and replaces the @racket[x] non-terminal
with a new one (which happens to be equivalent to the one that would
have been inherited).
The four-period ellipses indicates that the new language's