Generating Software from Specifications WS 2013/14 - File parsing1Sol.fw
@=~
~p maximum_input_line_length = infinity
This file contains the specification of a language
for sequences of statements.
Try to generate a processor for it.
If the parser generation indicates problems, analyse their
reasons and eliminate them.
The following file contains correct input for the processor:
Give an example for correct input:
~O~<whileSeq.ok~>~{~-
a = b; while c do c = d; i = k;
~}
The following file specifies the concrete syntax:
~O~<whileSeq.conx~>~{
Program: Statements.
Statements: Statements Statement / Statement.
Statement: 'while' Expression 'do' Statements /
Ident '=' Expression ';'.
Expression: Ident.
~}
It is ambigouous: It can not be decided which statements following
'do' belong to the loop or to the surrounding statement sequence.
The following grammar allows only one statement in a loop body:
(Change the file type into .con to use this grammar.)
~O~<whileSeq.cony~>~{
Program: Statements.
Statements: Statements Statement / Statement.
Statement: 'while' Expression 'do' Statement /
Ident '=' Expression ';'.
Expression: Ident.
~}
The following grammar closes the loop body by the keyword 'end':
(Change the file type into .con to use this grammar.)
~O~<whileSeq.conz~>~{
Program: Statements.
Statements: Statements Statement / Statement.
Statement: 'while' Expression 'do' Statements 'end' /
Ident '=' Expression ';'.
Expression: Ident.
~}
The following file specifies the non-literal tokens:
~O~<Expression.gla~>~{
Ident: C_IDENTIFIER
~}
Generiert mit Camelot | Probleme mit Camelot? | Geändert am: 13.11.2013