[r6rs-discuss] [Formal] Allow compilers to reject obvious violations

[Pascal Costanza]

On 25 Feb 2007, at 22:44, John Cowan wrote:

> William D Clinger scripsit:
>
>> According to the current draft R6RS, implementations
>> are not allowed to "abort at run time"; they would
>> have to raise a &violation exception, from which the
>> program might conceivably recover in a portable way.
>
> According to 2.7, however, if there is a syntax error (and
>
> 	(if (foo))
>
> is a syntax error, just as
>
> 	((((((
>
> is, the program or library is not allowed to begin execution.

Just for clarification: What does it mean that the program is "not  
allowed to begin execution"? Does this mean that it would not be  
valid to implement R6RS as a plain metacircular interpreter, without  
performing some additional syntactic check beforehand, that is?

Is a syntactic check not part of program execution in an interpreter?


Pascal

-- 
Pascal Costanza, mailto:pc at p-cos.net, http://p-cos.net
Vrije Universiteit Brussel, Programming Technology Lab
Pleinlaan 2, B-1050 Brussel, Belgium