expr/operator-builtin.go

62 lines
1.2 KiB
Go

// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.
// operator-builtin.go
package expr
import "io"
//-------- builtin term
func newBuiltinTerm(tk *Token) (inst *term) {
return &term{
tk: *tk,
children: make([]*term, 0, 1),
position: posPrefix,
priority: priSign,
evalFunc: evalBuiltin,
}
}
func evalBuiltin(ctx ExprContext, opTerm *term) (v any, err error) {
var childValue any
if childValue, err = opTerm.evalPrefix(ctx); err != nil {
return
}
count := 0
if IsString(childValue) {
module, _ := childValue.(string)
count, err = ImportInContextByGlobPattern(module)
} else {
var moduleSpec any
it := NewAnyIterator(childValue)
for moduleSpec, err = it.Next(); err == nil; moduleSpec, err = it.Next() {
if module, ok := moduleSpec.(string); ok {
if ImportInContext(module) {
count++
} else {
err = opTerm.Errorf("unknown builtin module %q", module)
break
}
} else {
err = opTerm.Errorf("expected string at item nr %d, got %s", it.Index()+1, TypeName(moduleSpec))
break
}
}
if err == io.EOF {
err = nil
}
}
if err == nil {
v = int64(count)
}
return
}
// init
func init() {
registerTermConstructor(SymKwBuiltin, newBuiltinTerm)
}