Probable Future Extensions ========================== AWK is a language similar to PERL, only considerably more elegant. Arnold Robbins Hey! Larry Wall This minor node briefly lists extensions and possible improvements that indicate the directions we are currently considering for `gawk'. The file `FUTURES' in the `gawk' distribution lists these extensions as well. Following is a list of probable future changes visible at the `awk' language level: Loadable Module Interface It is not clear that the `awk'-level interface to the modules facility is as good as it should be. The interface needs to be redesigned, particularly taking namespace issues into account, as well as possibly including issues such as library search path order and versioning. `RECLEN' variable for fixed length records Along with `FIELDWIDTHS', this would speed up the processing of fixed-length records. `PROCINFO["RS"]' would be `"RS"' or `"RECLEN"', depending upon which kind of record processing is in effect. Additional `printf' specifiers The 1999 ISO C standard added a number of additional `printf' format specifiers. These should be evaluated for possible inclusion in `gawk'. Databases It may be possible to map a GDBM/NDBM/SDBM file into an `awk' array. Large Character Sets It would be nice if `gawk' could handle UTF-8 and other character sets that are larger than eight bits. More `lint' warnings There are more things that could be checked for portability. Following is a list of probable improvements that will make `gawk''s source code easier to work with: Loadable Module Mechanics The current extension mechanism works (Note: Adding New Built-in Functions to `gawk'.), but is rather primitive. It requires a fair amount of manual work to create and integrate a loadable module. Nor is the current mechanism as portable as might be desired. The GNU `libtool' package provides a number of features that would make using loadable modules much easier. `gawk' should be changed to use `libtool'. Loadable Module Internals The API to its internals that `gawk' "exports" should be revised. Too many things are needlessly exposed. A new API should be designed and implemented to make module writing easier. Better Array Subscript Management `gawk''s management of array subscript storage could use revamping, so that using the same value to index multiple arrays only stores one copy of the index value. Integrating the DBUG Library Integrating Fred Fish's DBUG library would be helpful during development, but it's a lot of work to do. Following is a list of probable improvements that will make `gawk' perform better: An Improved Version of `dfa' The `dfa' pattern matcher from GNU `grep' has some problems. Either a new version or a fixed one will deal with some important regexp matching issues. Compilation of `awk' programs `gawk' uses a Bison (YACC-like) parser to convert the script given it into a syntax tree; the syntax tree is then executed by a simple recursive evaluator. This method incurs a lot of overhead, since the recursive evaluator performs many procedure calls to do even the simplest things. It should be possible for `gawk' to convert the script's parse tree into a C program which the user would then compile, using the normal C compiler and a special `gawk' library to provide all the needed functions (regexps, fields, associative arrays, type coercion, and so on). An easier possibility might be for an intermediate phase of `gawk' to convert the parse tree into a linear byte code form like the one used in GNU Emacs Lisp. The recursive evaluator would then be replaced by a straight line byte code interpreter that would be intermediate in speed between running a compiled program and doing what `gawk' does now. Finally, the programs in the test suite could use documenting in this Info file. Note: Making Additions to `gawk', if you are interested in tackling any of these projects.
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