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Feat[bmq]: support exists(x) function in subscription expressions (#594)
* Implement support for exists() in BISON expressions Signed-off-by: Dmitrii Petukhov <[email protected]> * Update src/groups/bmq/bmqeval/bmqeval_simpleevaluator.cpp Co-authored-by: Evgeny Malygin <[email protected]> Signed-off-by: Dmitrii Petukhov <[email protected]> * Update src/groups/bmq/bmqeval/bmqeval_simpleevaluator.h Co-authored-by: Evgeny Malygin <[email protected]> Signed-off-by: Dmitrii Petukhov <[email protected]> * Update src/groups/bmq/bmqeval/bmqeval_simpleevaluator.h Co-authored-by: Evgeny Malygin <[email protected]> Signed-off-by: Dmitrii Petukhov <[email protected]> * Update src/groups/bmq/bmqeval/bmqeval_simpleevaluator.t.cpp Co-authored-by: Evgeny Malygin <[email protected]> Signed-off-by: Dmitrii Petukhov <[email protected]> * Update src/groups/bmq/bmqeval/bmqeval_simpleevaluator.t.cpp Co-authored-by: Evgeny Malygin <[email protected]> Signed-off-by: Dmitrii Petukhov <[email protected]> * Refactor Exists::evaluate - make code smpler Signed-off-by: Dmitrii Petukhov <[email protected]> --------- Signed-off-by: Dmitrii Petukhov <[email protected]> Co-authored-by: Evgeny Malygin <[email protected]>
1 parent b6dfeae commit f3ba418

5 files changed

+102
-4
lines changed

‎src/groups/bmq/bmqeval/bmqeval_simpleevaluator.cpp

+25
Original file line numberDiff line numberDiff line change
@@ -364,5 +364,30 @@ bdld::Datum SimpleEvaluator::Not::evaluate(EvaluationContext& context) const
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return bdld::Datum::createBoolean(!value.theBoolean());
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}
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// -----------------------------
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// class SimpleEvaluator::Exists
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// -----------------------------
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SimpleEvaluator::Exists::Exists(const bsl::string& name)
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: d_name(name)
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{
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}
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#if defined(BSLS_COMPILERFEATURES_SUPPORT_RVALUE_REFERENCES) && \
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defined(BSLS_COMPILERFEATURES_SUPPORT_NOEXCEPT)
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SimpleEvaluator::Exists::Exists(bsl::string&& name) noexcept
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: d_name(bsl::move(name))
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{
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}
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#endif
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bdld::Datum SimpleEvaluator::Exists::evaluate(EvaluationContext& context) const
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{
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bdld::Datum value = context.d_propertiesReader->get(d_name,
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context.d_allocator);
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return bdld::Datum::createBoolean(!value.isError());
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}
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} // close package namespace
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} // close enterprise namespace

‎src/groups/bmq/bmqeval/bmqeval_simpleevaluator.h

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Original file line numberDiff line numberDiff line change
@@ -478,6 +478,41 @@ class SimpleEvaluator {
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evaluate(EvaluationContext& context) const BSLS_KEYWORD_OVERRIDE;
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};
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// ------
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// Exists
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// ------
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class Exists : public Expression {
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private:
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// DATA
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// The name of the property.
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bsl::string d_name;
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public:
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// CREATORS
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/// Create an object that evaluates property `name`, in the
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/// evaluation context, as a boolean.
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explicit Exists(const bsl::string& name);
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#if defined(BSLS_COMPILERFEATURES_SUPPORT_RVALUE_REFERENCES) && \
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defined(BSLS_COMPILERFEATURES_SUPPORT_NOEXCEPT)
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/// Create an object that evaluates property `name`, in the
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/// evaluation context, as a boolean.
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explicit Exists(bsl::string&& name) noexcept;
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#endif
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// ACCESSORS
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/// Evaluate `expression` passed to the constructor. If it is a
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/// boolean, return the negated value as a boolean Datum.
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/// Otherwise, set the error in the context to e_TYPE, stop the
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/// evaluation, and return a null datum.
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bdld::Datum
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evaluate(EvaluationContext& context) const BSLS_KEYWORD_OVERRIDE;
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};
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private:
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// SimpleEvaluator(const SimpleEvaluator& other) BSLS_KEYWORD_DELETED;
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// SimpleEvaluator& operator=(const SimpleEvaluator& other)
@@ -549,6 +584,7 @@ class SimpleEvaluator {
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friend class SimpleEvaluatorScanner; // for access to Expression hierarchy
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friend class CompilationContext; // for access to ExpressionPtr
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};
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// ========================
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// class CompilationContext
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// ========================

‎src/groups/bmq/bmqeval/bmqeval_simpleevaluator.t.cpp

+13
Original file line numberDiff line numberDiff line change
@@ -55,6 +55,7 @@ class MockPropertiesReader : public PropertiesReader {
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d_map["i_42"] = bdld::Datum::createInteger(42);
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d_map["i64_42"] = bdld::Datum::createInteger64(42, allocator);
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d_map["s_foo"] = bdld::Datum::createStringRef("foo", allocator);
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d_map["exists"] = bdld::Datum::createInteger(42);
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}
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// Destroy this object.
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@@ -520,6 +521,18 @@ static void test3_evaluation()
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{"i_0 != -9223372036854775807", true}, // -(2 ** 63) + 1
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{"i_0 != 9223372036854775807", true}, // 2 ** 63 - 1
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{"i_0 != -9223372036854775808", true}, // -(2 ** 63)
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// exists
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// Note that we allow to set a message property with name `exists`.
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// In this case the usage context defines whether it's a function call
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// or a property value.
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{"exists(i_42)", true},
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{"exists(non_existing_property)", false},
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{"!exists(non_existing_property) || non_existing_property > 41", true},
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{"exists(i_42) && i_42 > 41", true},
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{"exists(non_existing_property) && non_existing_property > 41", false},
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{"exists == 42", true},
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{"exists(exists)", true},
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};
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const TestParameters* testParametersEnd = testParameters +
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sizeof(testParameters) /

‎src/groups/bmq/bmqeval/bmqeval_simpleevaluatorparser.y

+23-4
Original file line numberDiff line numberDiff line change
@@ -75,6 +75,7 @@
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%token PLUS "+" MINUS "-";
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%token TIMES "*" DIVIDES "/" MODULUS "%";
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%token EQ "=" NE "<>" LT "<" LE "<=" GE ">=" GT ">";
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%token <bsl::string> EXISTS "exists";
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%left OR;
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%left AND;
@@ -84,6 +85,7 @@
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%left TIMES DIVIDES MODULUS;
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%right NOT "!";
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%type<bsl::string> variable;
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%type<SimpleEvaluator::ExpressionPtr> expression;
8890
%type<SimpleEvaluator::ExpressionPtr> predicate;
8991
%start predicate
@@ -95,18 +97,35 @@ predicate : expression END
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ctx.d_expression = $1;
9698
}
9799

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expression
100+
variable
99101
: PROPERTY
100102
{
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++ctx.d_numProperties;
104+
$$ = $1;
105+
}
106+
| EXISTS
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{
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++ctx.d_numProperties;
109+
$$ = $1;
110+
}
101111

102-
#if defined(BSLS_COMPILERFEATURES_SUPPORT_RVALUE_REFERENCES) \
112+
expression
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: variable {
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#if defined(BSLS_COMPILERFEATURES_SUPPORT_RVALUE_REFERENCES) \
103115
&& defined(BSLS_COMPILERFEATURES_SUPPORT_NOEXCEPT)
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$$ = ctx.makeUnaryExpression<SimpleEvaluator::Property, bsl::string>(bsl::move($1));
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#else
106118
$$ = ctx.makeUnaryExpression<SimpleEvaluator::Property, bsl::string>($1);
107119
#endif
108-
109-
++ctx.d_numProperties;
120+
}
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| EXISTS LPAR variable RPAR
122+
{
123+
#if defined(BSLS_COMPILERFEATURES_SUPPORT_RVALUE_REFERENCES) \
124+
&& defined(BSLS_COMPILERFEATURES_SUPPORT_NOEXCEPT)
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$$ = ctx.makeUnaryExpression<SimpleEvaluator::Exists, bsl::string>(bsl::move($3));
126+
#else
127+
$$ = ctx.makeUnaryExpression<SimpleEvaluator::Exists, bsl::string>($3);
128+
#endif
110129
}
111130
| INTEGER
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{ $$ = ctx.makeLiteral<SimpleEvaluator::IntegerLiteral>($1); }

‎src/groups/bmq/bmqeval/bmqeval_simpleevaluatorscanner.l

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Original file line numberDiff line numberDiff line change
@@ -32,6 +32,11 @@
3232
return SimpleEvaluatorParser::make_FALSE();
3333
}
3434

35+
"exists" {
36+
updatePosition();
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return SimpleEvaluatorParser::make_EXISTS(yytext);
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}
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3540
[a-zA-Z][a-zA-Z0-9_.]* {
3641
updatePosition();
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return SimpleEvaluatorParser::make_PROPERTY(yytext);

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