Hello devs,
Since an expression syntax has been added to pgbench, I find that the
readability of expressions is not great. An extra '=' improves the
situation for me:
\set id = 1 + abs((:id * 1021) % (100000 * :scale))
seems slightly better than:
\set id 1 + abs((:id * 1021) % (100000 * :scale))
But that is debatable!
The attached patch just ignores a leading '=' in a pgbench expression.
--
Fabien.
diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index a808546..39ee4b3 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -751,13 +751,14 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
<variablelist>
<varlistentry>
<term>
- <literal>\set <replaceable>varname</> <replaceable>expression</></literal>
+ <literal>\set <replaceable>varname</> = <replaceable>expression</></literal>
</term>
<listitem>
<para>
Sets variable <replaceable>varname</> to an integer value calculated
from <replaceable>expression</>.
+ The <literal>=</> character for assignment is optional.
The expression may contain integer constants such as <literal>5432</>,
references to variables <literal>:</><replaceable>variablename</>,
and expressions composed of unary (<literal>-</>) or binary operators
@@ -768,8 +769,8 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
<para>
Examples:
<programlisting>
-\set ntellers 10 * :scale
-\set aid (1021 * :aid) % (100000 * :scale) + 1
+\set ntellers = 10 * :scale
+\set aid = (1021 * :aid) % (100000 * :scale) + 1
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/bin/pgbench/exprparse.y b/src/bin/pgbench/exprparse.y
index e68631e..8b39d9c 100644
--- a/src/bin/pgbench/exprparse.y
+++ b/src/bin/pgbench/exprparse.y
@@ -48,6 +48,8 @@ static PgBenchExpr *make_op(char operator, PgBenchExpr *lexpr,
%%
result: expr { expr_parse_result = $1; }
+ | '=' expr { expr_parse_result = $2; }
+ ;
expr: '(' expr ')' { $$ = $2; }
| '+' expr %prec UMINUS { $$ = $2; }
diff --git a/src/bin/pgbench/exprscan.l b/src/bin/pgbench/exprscan.l
index 5331ab7..2df83d5 100644
--- a/src/bin/pgbench/exprscan.l
+++ b/src/bin/pgbench/exprscan.l
@@ -46,6 +46,7 @@ space [ \t\r\f]
"%" { yycol += yyleng; return '%'; }
"(" { yycol += yyleng; return '('; }
")" { yycol += yyleng; return ')'; }
+"=" { yycol += yyleng; return '='; }
:[a-zA-Z0-9_]+ {
yycol += yyleng;
--
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