vera

Installation

go get https://github.com/Ro5bert/vera

The CLI binary can be built from the cli folder; for example:

cd $(go env GOPATH)/src/github.com/Ro5bert/vera/cli && go build -o vera main.go

Syntax

0	False
1	True
a-z, A-Z	Statement
(...)	Grouping/explicit binary operator precedence
!	Negate
&	AND
|	OR
^	XOR
>	Conditional/Implication
=	Bi-conditional/Equality/IFF

Limitations

• There is a maximum of 52 atomic statements (26 lowercase letters + 26 uppercase letter = 52). (Although, I am not sure why or how you would have 52 atomic statements... performance is O(2ⁿ) where n is number of atomic statements).
• To avoid subjectivity in operator precedence, all binary operators are assigned equal precedence and must be parenthesized as necessary (even if the operators are all AND, for example); this may change in the future. (Negation, of course, still has higher precedence than all binary operators.)

Sample CLI Output

Use as a Library Example

// Assuming "github.com/Ro5bert/vera" is imported

stmt, truth, err := vera.Parse("a > b")
if err != nil {
    // handle error
}
// Iterate over all sets of truth values and print out the stmt evaluated at each set:
for ; truth.Val < (1 << len(truth.Names)); truth.Val++ {
    fmt.Println(stmt.Eval(truth))
}