ref: 02fdefe15a8152dbee66519fc3a14c186650485f
parent: 7d6f64c59093d5a8e6ef35d8c012395a6eff64c1
author: Ori Bernstein <ori@eigenstate.org>
date: Fri Dec 6 06:53:44 EST 2019
hoc: don't nest calls to follow() when lexing ++/+= and --/-= (#287) The code had a nested use of the follow() function that could cause +=+ and -=- to register as ++ and --. The first follow() to execute could consume a character and match and then the second follow() could consume another character and match. For example i-=-10 would result in a syntax error and i-=- would decrement i. (imported from plan9port commit f1dd3f065a97f57bf59db2e3284868e181734159)
--- a/sys/src/cmd/hoc/hoc.y
+++ b/sys/src/cmd/hoc/hoc.y
@@ -214,8 +214,8 @@
return STRING;
}
switch (c) {- case '+': return follow('+', INC, follow('=', ADDEQ, '+'));- case '-': return follow('-', DEC, follow('=', SUBEQ, '-'));+ case '+': return follow('+', INC, '+') == INC ? INC : follow('=', ADDEQ, '+');+ case '-': return follow('-', DEC, '-') == DEC ? DEC : follow('=', SUBEQ, '-'); case '*': return follow('=', MULEQ, '*'); case '/': return follow('=', DIVEQ, '/'); case '%': return follow('=', MODEQ, '%');--
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