4.14 Macros Are Static

4.14 Macros Are Static

In FunnelWeb, the actions of 

macro definition

  and 

macro

expansion

  occur during two separate phases (parser and tangle)

Tutorial

and cannot be interleaved. As a result, the FunnelWeb macro

facility is completely static. It is not possible for one macro to

Developer

define another while the first macro is being expanded; each

must be defined statically. It is not possible to define a macro to

Reference

even assist in the definition of other macros. Because the

scanner, parser, analyser, and tangler phases are all invoked

1 Introduction

sequentially, there is no room for feedback of definitions

2 Interface

between different levels (e.g. the user cannot define a macro for

3 Scanner

the vskip pragma).

4 Parser

5 Analyser

This lack of power is fully intentional. By totally excluding the

more incomprehensible ways in which a general purpose macro

6 Tangle

preprocessor can be used, FunnelWeb provides definite

7 Weave

guarantees to the reader of its input files:

8 Shell

FunnelWeb guarantees that a piece of text does not

G   

9 Commands

contain a macro call unless it contains the special

10 Glossary

character followed by < or #.

11 References

FunnelWeb allows calls to be made to macros that are

G   

defined later in the input file.

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Copyright   Ross N. Williams 1992,1999. All rights

reserved.

http://www.ross.net/funnelweb/reference/parser_static.html [3/3/2000 10:47:03 PM]