Expression Grammar

Filter Grammar

Language Issues

Filter and Expression Keywords

Expression Grammar

The FdoExpression::Parse() method supports the following expression grammar:

<Expression> ::= '(' Expression ')'

| <UnaryExpression>

| <BinaryExpression>

| <Function>

| <Identifier>

| <ValueExpression>

<BinaryExpression> ::=

<Expression> '+' <Expression>

| <Expression> '-' <Expression>

| <Expression> '*' <Expression>

| <Expression> '/' <Expression>

<DataValue> ::=

TRUE

| FALSE

| DATETIME

| DOUBLE

| INTEGER

| STRING

| BLOB

| CLOB

| NULL

<Function> ::= <Identifier> '(' <ExpressionCollection> ')'

<ExpressionCollection> ::=

| <Expression>

| <ExpressionCollection> ',' <Expression>

<GeometryValue> ::= GEOMFROMTEXT '(' STRING ')'

<Identifier> ::= IDENTIFIER

<ValueExpression> ::= <LiteralValue> | <Parameter>;

<LiteralValue> ::= <GeometryValue> | <DataValue>

<Parameter> ::= PARAMETER | ':'STRING

<UnaryExpression> ::= '-' <Expression>

Expression Operator Precedence

The precedence is shown in YACC notation, that is, the highest precedence operators are at the bottom.

%left Add Subtract

%left Multiply Divide

%left Negate