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一个SQL解析器

This directory contains the parser for DDF.  The components are as follows

Makefile
README

PROGRAM FILES
dsl.l           Lex for parser
dsl.y           Yacc for parser
parser.c        Main parser function
rwsearch.c      Reserved word table search functions
tpar.c		Main for testing parser

INCLUDE FILES
tmprws.h	template for parser.h; filled with data generated from
		y.tab.h (output of yacc)
ddf.h		definition of type DDFRUN
gtok.h		Parser tree token definitions

AUXILIARY SHELL SCRIPTS AND PROGRAMS
ed0		edit script for lex; executed after generating lex.yy.c
		from dsl.l; removes the definitions of makros input(),
		output(c), and unput(c) - they are redefined in parser.c
ed0.out		stdout protocol of ed0 actions
ed1		edit script for yacc; modifies the output y.tab.h of
		yacc to produce y.h; y.h is sorted and piped through phm
		to produce rnums and rwords
ed1.out		stdout protocol of ed1 actions
ed2		edit script for yacc; generates file nt containing 'wc y.h';
		opens tmprws.h, inserts nt, rnums, and rwords in
		appropriate places, and writes parser.h
ed2.out		stdout protocol of ed2 actions
phm.c		reads y.h to generate rnums and rwords
phm		result of cc -o phm phm.c

TEMPFILES
lex.yy.c	lex output generated from dsl.l
y.tab.c		yacc program ( yyparse() ) generated from dsl.y
y.tab.h		include with token definitions generated by yacc
y.output	states and transitions documented by yacc
rnums
rwords
nt
parser.h        parser related tables, defines and variables;
		generated by ed2
y.tab.o		object module yyparse
parser.o	object module parse

TEST
vtest2		list of sql statements
tf.l		lex definition to eliminate numbers from vtest2
tf.yy.c		lex output generated from tf.l
tf		result of cc -0 tf tf.yy.c -ll
tpar		main test program; reads stdin and writes pt_file
testpar		shell script to execute tpar: tf < vtest2 | tpar
pt_file		parse tree test output file