12 Compile-time Options
TE_FLOAT
double is the default data type used for the parser’s variable types, parameters, and return types. Compile with TE_FLOAT defined to use float instead.
Refer to floating-point numbers for more information.
This flag will also disable all bitwise functions and operators.
TE_LONG_DOUBLE
Compile with TE_LONG_DOUBLE defined to use long double as the default data type.
Depending on the compiler, this may provide support for handling uint64_t values. Call te_parser::supports_64bit() (or SUPPORTS64BIT() in an expression at runtime) to confirm this.
TE_BITWISE_OPERATORS
By default, the operators &, |, and ^ represent logical AND, logical OR, and exponentiation. If TE_BITWISE_OPERATORS is defined, then they will represent bitwise AND, OR, and XOR.
TE_BRACKETS_AS_PARENS
Define this flag to treat [] pairs the same as (). This can be useful if using the parser for a debugger’s watch window. For example, an expression such as [rsp+1000] would be evaluated as 1000 being added with the variable rsp. In this context, rsp could represent a memory address in the debugger.
TE_NO_BOOKKEEPING
By default, the parser will keep track of all functions and variables used in the last expression it evaluated. From this, the presence of a function or variable in the expression can be verified via is_function_used() and is_variable_used().
Turning this option off can provide a small optimization, as it will result in less heap allocations and search operations. Defining TE_NO_BOOKKEEPING will disable this feature.
TE_POW_FROM_RIGHT
By default, TinyExpr++ does exponentiation from left to right. For example:
a^b^c == (a^b)^c and -a^b == (-a)^b
This is by design; it’s the way that spreadsheets do it (e.g., LibreOffice Calc, Excel, Google Sheets).
If you would rather have exponentiation work from right to left, you need to define TE_POW_FROM_RIGHT when compiling. With TE_POW_FROM_RIGHT defined, the behavior is:
a^b^c == a^(b^c) and -a^b == -(a^b)
That will match how many scripting languages do it (e.g., Python, Ruby).
Note that symbols can be defined by passing them to your compiler’s command line (or in a CMake configuration) as such: -DTE_POW_FROM_RIGHT
C++20 Features
If compiling as C++20 (and TE_FLOAT is not defined), then the following functions and operators will be available:
BITLROTATE8BITLROTATE16BITLROTATE32BITLROTATE64BITLROTATEBITRROTATE8BITRROTATE16BITRROTATE32BITRROTATE64BITRROTATE<<<(unsigned 64-bit left rotation)>>>(unsigned 64-bit right rotation)