build-sys: import build system from darvaza.org/core

Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-08-28 22:10:36 +00:00
1 changed files with 0 additions and 54 deletions
@@ -1,54 +0,0 @@
 // Package lexer provides basic helpers to implement parsers
 package lexer
 import "io"
 // StateFn is a State Function of the parser
 type StateFn func() (StateFn, error)
 // Run runs a state machine until the state function either
 // returns nil or an error
 func Run(fn StateFn) error {
 	var err error
 	for fn != nil && err == nil {
 		fn, err = fn()
 	}
 	return err
 }
 // Accept consumes a rune from the source if it meets the condition.
 // it returns true if the condition was met and false if it wasn't.
 func Accept(src io.RuneScanner, cond func(r rune) bool) bool {
 	r, _, err := src.ReadRune()
 	switch {
 	case err != nil:
 		return false
 	case cond(r):
 		return true
 	default:
 		_ = src.UnreadRune()
 		return false
 	}
 }
 // AcceptAll consumes runes from the source as long as they meet the
 // condition. it returns true if the condition was met for at least one rune,
 // and false if it wasn't.
 func AcceptAll(src io.RuneScanner, cond func(r rune) bool) bool {
 	var accepted bool
 	for {
 		r, _, err := src.ReadRune()
 		switch {
 		case err != nil:
 			return accepted
 		case cond(r):
 			accepted = true
 		default:
 			_ = src.UnreadRune()
 			return accepted
 		}
 	}
 }