q/src/core/Define.go

33 lines
787 B
Go

package core
import (
"git.akyoto.dev/cli/q/src/errors"
"git.akyoto.dev/cli/q/src/expression"
"git.akyoto.dev/cli/q/src/scope"
"git.akyoto.dev/cli/q/src/token"
)
// Define defines a new variable.
func (f *Function) Define(leaf *expression.Expression) (*scope.Variable, error) {
name := leaf.Token.Text(f.File.Bytes)
variable := f.VariableByName(name)
if variable != nil {
return nil, errors.New(&errors.VariableAlreadyExists{Name: name}, f.File, leaf.Token.Position)
}
uses := token.Count(f.Body, f.File.Bytes, token.Identifier, name) - 1
if uses == 0 {
return nil, errors.New(&errors.UnusedVariable{Name: name}, f.File, leaf.Token.Position)
}
variable = &scope.Variable{
Name: name,
Register: f.NewRegister(),
Alive: uses,
}
return variable, nil
}