# New Ticket Created by Florian Hatat # Please include the string: [perl #59784] # in the subject line of all future correspondence about this issue. # <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=59784 >
Hi, PGE currently only supports one operator table, while some languages (for example the OCaml language, which has "type expressions") may need more than one. This patch updates Per6Grammar.pir to add support for multiple optables: each rule with the option "is optable" now creates a new PGE::OPTable with a unique identifier (using the "unique" method of CodeString). In the generated "__onload" sub, the operators are still added to the tables using the single "optable" variable, which holds the latest defined optable. This implies that once a new optable is defined, the previous ones cannot be extended any more. The diff on the code itself is actually quite small: it was mainly a matter of moving some code around, and adding the unique identifier instead of the "$optable" static name. It contains an update for docs/pct/pct_optable_guide.pod as well. It was made against the 0.7.1 sources. -- Florian, http://openweb.eu.org/ http://www.linux-france.org/
--- runtime/parrot/library/PGE/Perl6Grammar.pir 2008-09-17 00:14:12.000000000 +0200
+++ runtime/parrot/library/PGE/Perl6Grammar.new 2008-10-10 12:57:53.000000000 +0200
@@ -192,8 +192,6 @@
ns_optable:
$P0 = ns['optable']
if $P0 == '' goto iter_loop
- initpir.emit(" optable = new 'PGE::OPTable'")
- initpir.emit(" set_hll_global ['%0'], '$optable', optable", namespace)
initpir .= $P0
goto iter_loop
iter_end:
@@ -290,16 +288,24 @@
goto with_rulepir
rulepir_optable:
## this is a special rule generated via the 'is optable' trait
+ .local pmc optable
+ $P0 = nstable[namespace]
+ optable = $P0['optable']
+ $S0 = optable.unique('optable_')
+
rulepir = new 'CodeString'
- rulepir.emit(<<' END', namespace, name)
+ rulepir.emit(<<' END', namespace, name, $S0)
.namespace [ "%0" ]
.sub "%1"
.param pmc mob
.param pmc adverbs :named :slurpy
- $P0 = get_hll_global ["%0"], "$optable"
+ $P0 = get_hll_global ["%0"], "$%2"
.return $P0.'parse'(mob, 'rulename'=>"%1", adverbs :named :flat)
.end
END
+
+ optable.emit(" optable = new 'PGE::OPTable'")
+ optable.emit(" set_hll_global ['%0'], '$%1', optable", namespace, $S0)
with_rulepir:
## add to set of rules
--- docs/pct/pct_optable_guide.pod 2008-09-17 00:14:34.000000000 +0200
+++ docs/pct/pct_optable_guide.new 2008-10-10 13:23:41.000000000 +0200
@@ -426,7 +426,22 @@
=item * How many operator tables can I use in my language?
-{{ XXX I think one only? Anybody? }}
+You can use as many operator tables as you like: each operator table is declared
+in a rule, as above. Operators automatically belong to the last operator table
+defined before their C<proto> rule. This means, in particular, that you cannot
+add any more operator to an optable once you've started another optable.
+
+The following example defines two optables C<expr> and C<otherexpr>, with some
+operators:
+
+ rule expr is optable { ... }
+ proto 'infix:+' is precedence('1') { ... }
+ proto 'infix:*' is tighter('infix:+') { ... }
+ proto 'term:' is tighter('infix:*') is parsed(&term) { ... }
+
+ rule otherexpr is optable { ... }
+ proto 'infix:+' is precedence('1')
+ proto 'term:' is tighter('infix:+') is parsed(&otherterm) { ... }
=item * How does an optable parser work?
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