evaler

func BigratToBigint ¶

func BigratToBigint(bigrat *big.Rat) *big.Int

BigratToInt converts a *big.Rat to a *big.Int (with truncation)

func BigratToFloat ¶

func BigratToFloat(bigrat *big.Rat) float64

BigratToFloat converts a *big.Rat to a float64 (with loss of precision).

func BigratToInt ¶

func BigratToInt(bigrat *big.Rat) (int64, error)

BigratToInt converts a *big.Rat to an int64 (with truncation); it returns an error for integer overflows.

func Eval ¶

func Eval(expr string) (result *big.Rat, err error)

Eval takes an infix string arithmetic expression, and evaluates it

Usage:

result, err := evaler.Eval("1+2")

Returns: the result of the evaluation, and any errors

func EvalWithVariables ¶

func EvalWithVariables(expr string, variables map[string]string) (result *big.Rat, err error)

EvalWithVariables allows variables to be passed into expressions, for example evaluate "x + 1" where x=5

func FloatToBigrat ¶

func FloatToBigrat(float float64) *big.Rat

FloatToBigrat converts a float64 to a *big.Rat.

func Tokenise ¶

func Tokenise(expr string) []string

Tokenise takes an expr string and converts it to a slice of tokens

Tokenise puts spaces around all non-numbers, removes leading and trailing spaces, then splits on spaces