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authorCharlie Stanton <charlie@shtanton.xyz>2023-04-19 13:23:47 +0100
committerCharlie Stanton <charlie@shtanton.xyz>2023-04-19 13:27:38 +0100
commitaea1a08d6a9d378137d467d3e1f1ccc40232b725 (patch)
tree680e7c913b3ea782557d51968e24d7fa5c4d450a /subex/arithmetic.go
parentb48dcb0d37bd3db854927df25e6ff41d07501026 (diff)
downloadstred-go-aea1a08d6a9d378137d467d3e1f1ccc40232b725.tar
Adds the negate operator
Negates all of the numbers produced by its content subex
Diffstat (limited to 'subex/arithmetic.go')
-rw-r--r--subex/arithmetic.go33
1 files changed, 33 insertions, 0 deletions
diff --git a/subex/arithmetic.go b/subex/arithmetic.go
index 7200ac7..5497a68 100644
--- a/subex/arithmetic.go
+++ b/subex/arithmetic.go
@@ -85,3 +85,36 @@ func multiplyValues(atoms []walk.Atom) ([]walk.Atom, error) {
return []walk.Atom{walk.ValueNumber(product)}, nil
}
}
+
+// Does tries to cast all to numbers and negates them
+func negateValues(atoms []walk.Atom) ([]walk.Atom, error) {
+ var negatedNumbers []walk.Atom
+ values, err := walk.MemoryCompound(atoms)
+ if err != nil {
+ return nil, err
+ }
+ for _, value := range values {
+ switch v := value.(type) {
+ case walk.ValueNull:
+ negatedNumbers = append(negatedNumbers, walk.ValueNumber(0))
+ case walk.ValueBool:
+ if bool(v) {
+ negatedNumbers = append(negatedNumbers, walk.ValueNumber(-1))
+ } else {
+ negatedNumbers = append(negatedNumbers, walk.ValueNumber(0))
+ }
+ case walk.ValueNumber:
+ negatedNumbers = append(negatedNumbers, walk.ValueNumber(-v))
+ case walk.ValueString:
+ num, err := strconv.ParseFloat(string(v), 64)
+ if err == nil {
+ negatedNumbers = append(negatedNumbers, walk.ValueNumber(-num))
+ } else {
+ return nil, errors.New("Tried to sum non-castable string")
+ }
+ default:
+ return nil, errors.New("Tried to sum non-number")
+ }
+ }
+ return negatedNumbers, nil
+}