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hoc: don't nest calls to follow() when lexing ++/+= and --/-= (#287)

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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.
This commit is contained in:
deepcube 2019-09-19 10:10:28 -07:00 • committed by Dan Cross
parent 9389de63d7
commit f1dd3f065a
1 changed files with 2 additions and 2 deletions
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4
src/cmd/hoc/hoc.y
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@ -215,8 +215,8 @@ yylex(void) /* hoc6 */
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, '%');