elvish/pkg/eval/builtin_ns.go
Qi Xiao 6e8ecc8bd5 pkg/eval: Cleanups for reducing the API surface area number of files.
- Move NewEnvListVar to pkg/eval/vars.

- De-export GlobPattern, GlobFlag and ExternalCmd.

- Merge editor.go and chdir.go into eval.go, value_helper.go into compile_value.go.

- Remove eval_internal_test.go and replace it with a new test for $pid.
2021-01-05 04:33:52 +00:00

94 lines
1.9 KiB
Go

package eval
import (
"strconv"
"syscall"
"github.com/elves/elvish/pkg/eval/vars"
)
//elvdoc:var _
//
// A blackhole variable.
//
// Values assigned to it will be discarded. Referencing it always results in $nil.
//elvdoc:var args
//
// A list containing command-line arguments. Analogous to `argv` in some other
// languages. Examples:
//
// ```elvish-transcript
// ~> echo 'put $args' > args.elv
// ~> elvish args.elv foo -bar
// ▶ [foo -bar]
// ~> elvish -c 'put $args' foo -bar
// ▶ [foo -bar]
// ```
//
// As demonstrated above, this variable does not contain the name of the script
// used to invoke it. For that information, use the `src` command.
//
// @cf src
//elvdoc:var false
//
// The boolean false value.
//elvdoc:var ok
//
// The special value used by `?()` to signal absence of exceptions.
//elvdoc:var nil
//
// A special value useful for representing the lack of values.
//elvdoc:var paths
//
// A list of search paths, kept in sync with `$E:PATH`. It is easier to use than
// `$E:PATH`.
//elvdoc:var pid
//
// The process ID of the current Elvish process.
//elvdoc:var pwd
//
// The present working directory. Setting this variable has the same effect as
// `cd`. This variable is most useful in a temporary assignment.
//
// Example:
//
// ```elvish
// ## Updates all git repositories
// for x [*/] {
// pwd=$x {
// if ?(test -d .git) {
// git pull
// }
// }
// }
// ```
//
// Etymology: the `pwd` command.
//
// @cf cd
//elvdoc:var true
//
// The boolean true value.
var builtinNs = NsBuilder{
"_": vars.NewBlackhole(),
"pid": vars.NewReadOnly(strconv.Itoa(syscall.Getpid())),
"ok": vars.NewReadOnly(OK),
"nil": vars.NewReadOnly(nil),
"true": vars.NewReadOnly(true),
"false": vars.NewReadOnly(false),
"paths": vars.NewEnvListVar("PATH"),
}
func addBuiltinFns(fns map[string]interface{}) {
builtinNs.AddGoFns("", fns)
}