From 205405f0bf1d2fa37d4c8170c11689a2937f5d9c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 1 Mar 2016 06:23:36 +0100 Subject: Generalize bit string comprehensions The expression in a bit string comprehension is limited to a literal bit string expression. That is, the following code is legal: << <> || X <- List >> but not this code: << foo(X) || X <- List >> The limitation is annoying. For one thing, tools that transform the abstract format must be careful not to produce code such as: << begin %% Some instrumentation code. <> end || X <- List >> One reason for the limitation could be that we'll get reduce/reduce conflicts if we try to allow an arbitrary expression in a bit string comprehension: binary_comprehension -> '<<' expr '||' lc_exprs '>>' : {bc,?anno('$1'),'$2','$4'}. Unfortunately, there does not seem to be an easy way to work around that problem. The best we can do is to allow 'expr_max' expressions (as in the binary syntax): binary_comprehension -> '<<' expr_max '||' lc_exprs '>>' : {bc,?anno('$1'),'$2','$4'}. That will work, but functions calls must be enclosed in parentheses: << (foo(X)) || X <- List >> --- lib/tools/src/cover.erl | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'lib/tools/src') diff --git a/lib/tools/src/cover.erl b/lib/tools/src/cover.erl index 3732b0fc85..87de31919f 100644 --- a/lib/tools/src/cover.erl +++ b/lib/tools/src/cover.erl @@ -2002,9 +2002,7 @@ munge_expr({lc,Line,Expr,Qs}, Vars) -> {MungedQs, Vars3} = munge_qualifiers(Qs, Vars2), {{lc,Line,MungedExpr,MungedQs}, Vars3}; munge_expr({bc,Line,Expr,Qs}, Vars) -> - {bin,BLine,[{bin_element,EL,Val,Sz,TSL}|Es]} = Expr, - Expr2 = {bin,BLine,[{bin_element,EL,Val,Sz,TSL}|Es]}, - {MungedExpr,Vars2} = munge_expr(Expr2, Vars), + {MungedExpr,Vars2} = munge_expr(?BLOCK1(Expr), Vars), {MungedQs, Vars3} = munge_qualifiers(Qs, Vars2), {{bc,Line,MungedExpr,MungedQs}, Vars3}; munge_expr({block,Line,Body}, Vars) -> -- cgit v1.2.3