Add a termstack, some infix grammar rules.

perl6 · Oct 19, 2009 · f4c2dcb · f4c2dcb
1 parent 5648720
commit f4c2dcb
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Showing 2 changed files with 26 additions and 3 deletions.
diff --git a/src/NQP/Grammar.pm b/src/NQP/Grammar.pm
@@ -5,6 +5,10 @@ token TOP { <EXPR> }
 proto token term { <...> }
 token term:sym<value> { <value> }
 
+proto token infix { <...> }
+token infix:sym<+> { '+' }
+token infix:sym<-> { '-' }
+
 token value {
     | <integer>
     | <quote_delimited>

diff --git a/src/cheats/hll-grammar.pir b/src/cheats/hll-grammar.pir
@@ -358,15 +358,34 @@ An operator precedence parser.
     .local string termish
     termish = 'termish'
 
-    .local pmc here, term
-    .local int pos
+    .local pmc opstack, termstack
+    opstack = new ['ResizablePMCArray']
+    .lex '@opstack', opstack
+    termstack = new ['ResizablePMCArray']
+    .lex '@termstack', termstack
+
+    .local pmc here, infix, from, pos
     (here, pos) = self.'!cursor_start'()
 
     here = here.termish()
     unless here goto fail
-
+    push termstack, here
+
+  term_done:
+    # $I0 = elements termstack
+    # if $I0 != 1 goto err_internal
+    from = getattribute self, '$!from'
+    pos = getattribute here, '$!pos'
+    here = pop termstack
+    setattribute here, '$!from', from
+    setattribute here, '$!pos', pos
+    here.'!reduce'('EXPR')
   fail:
     .return (here)
+
+  err_internal:
+    $I0 = termstack
+    here.'panic'('Internal operator parser error, @termstack == ', $I0)
 .end
 
 =cut