Get rid of backtracking in jsonpath_scan.l

Non-backtracking flex parsers work faster than backtracking ones.  So, this
commit gets rid of backtracking in jsonpath_scan.l.  That required explicit
handling of some cases as well as manual backtracking for some cases.  More
regression tests for numerics are added.

Discussion: https://mail.google.com/mail/u/0?ik=a20b091faa&view=om&permmsgid=msg-f%3A1628425344167939063
Author: John Naylor, Nikita Gluknov, Alexander Korotkov

1 files changed, 30 insertions, 0 deletions

diff --git a/src/test/regress/sql/jsonpath.sql b/src/test/regress/sql/jsonpath.sql
index e5f3391a666..9171ddbc6cd 100644
--- a/src/test/regress/sql/jsonpath.sql
+++ b/src/test/regress/sql/jsonpath.sql
@@ -66,6 +66,8 @@ select '$[$[0] ? (last > 0)]'::jsonpath;
 
 select 'null.type()'::jsonpath;
 select '1.type()'::jsonpath;
+select '(1).type()'::jsonpath;
+select '1.2.type()'::jsonpath;
 select '"aaa".type()'::jsonpath;
 select 'true.type()'::jsonpath;
 select '$.double().floor().ceiling().abs()'::jsonpath;
@@ -145,3 +147,31 @@ select '$ ? (@.a < +0.1e+1)'::jsonpath;
 select '$ ? (@.a < 10.1e+1)'::jsonpath;
 select '$ ? (@.a < -10.1e+1)'::jsonpath;
 select '$ ? (@.a < +10.1e+1)'::jsonpath;
+
+select '0'::jsonpath;
+select '00'::jsonpath;
+select '0.0'::jsonpath;
+select '0.000'::jsonpath;
+select '0.000e1'::jsonpath;
+select '0.000e2'::jsonpath;
+select '0.000e3'::jsonpath;
+select '0.0010'::jsonpath;
+select '0.0010e-1'::jsonpath;
+select '0.0010e+1'::jsonpath;
+select '0.0010e+2'::jsonpath;
+select '1e'::jsonpath;
+select '1.e'::jsonpath;
+select '1.2e'::jsonpath;
+select '1.2.e'::jsonpath;
+select '(1.2).e'::jsonpath;
+select '1e3'::jsonpath;
+select '1.e3'::jsonpath;
+select '1.e3.e'::jsonpath;
+select '1.e3.e4'::jsonpath;
+select '1.2e3'::jsonpath;
+select '1.2.e3'::jsonpath;
+select '(1.2).e3'::jsonpath;
+select '1..e'::jsonpath;
+select '1..e3'::jsonpath;
+select '(1.).e'::jsonpath;
+select '(1.).e3'::jsonpath;