5 Analyser

5 Analyser

The effect of the parser is to construct a macro table containing

a representation of all the macros defined within the document,

Tutorial

and a document list which contains a complete representation of

the entire document. If there are no error diagnostics (or worse)

Developer

at the end of the parser run, FunnelWeb invokes the analyser

which tests for the following conditions and flags them with

Reference

errors if they arise.

1 Introduction

No macros defined in the input file.

G   

2 Interface

No macros connected to output files.

G   

3 Scanner

Call of an undefined macro.

G   

4 Parser

Call having the wrong number of parameters.

G   

5 Analyser

Call of a macro that is connected to an output file.

G   

6 Tangle

No calls made to a macro without the @Z option.

G   

7 Weave

More than one call made to a macro without the @M

G   

8 Shell

option.

9 Commands

Directly or indirectly recursively defined macros.

G   

10 Glossary

Unnamed sections that contain no macro definitions.

G   

11 References

FunnelWeb performs a static analysis to detect recursion.

SEARCH

Unfortunately, the recursion detection algorithm flags all

macros that have an infinite expansion rather than just all

macros with a recursive definition. If A calls B, and B calls C,

and C calls B, then FunnelWeb will flag A as well as B and C.

It is hoped that this problem will be fixed in a later version.

Because FunnelWeb does not provide any kind of conditional

feature, the prevention of recursion does not represent a

curtailment of expressive power.

Macros may be invoked recursively, but may not be recursive.

Thus:

@! LEGAL   recursive invocation.

@@(@@(Walrus@)@)

@! ILLEGAL recursive definition.

@$@==@{@@}

http://www.ross.net/funnelweb/reference/analyser.html (1 of 2) [3/3/2000 10:43:04 PM]