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Merge pull request 'lexer: constants and helpers' (#9)

Reviewed-on: #9
pull/10/head v0.3.6
Alejandro Mery 1 year ago
parent
commit
3bd2c58fc3
  1. 9
      lexer/error.go
  2. 41
      lexer/runes.go

9
lexer/error.go

@ -1,6 +1,7 @@
package lexer
import (
"errors"
"fmt"
"strings"
)
@ -9,6 +10,14 @@ var (
_ error = (*Error)(nil)
)
var (
// ErrUnacceptableRune indicates the read rune isn't acceptable in the context
ErrUnacceptableRune = errors.New("rune not acceptable in context")
// ErrNotImplemented indicates something hasn't been implemented yet
ErrNotImplemented = errors.New("not implemented")
)
// Error represents a generic parsing error
type Error struct {
Filename string

41
lexer/runes.go

@ -0,0 +1,41 @@
package lexer
import (
"strings"
"unicode"
)
// NewIsNot generates a rune condition checker that reverses the
// decision of the given checker.
func NewIsNot(cond func(rune) bool) func(rune) bool {
return func(r rune) bool {
return !cond(r)
}
}
// NewIsIn generates a rune condition checker that accepts runes
// contained on the provided string
func NewIsIn(s string) func(rune) bool {
return func(r rune) bool {
return strings.ContainsRune(s, r)
}
}
// NewIsOneOf generates a run condition checker that accepts runes
// accepted by any of the given checkers
func NewIsOneOf(s ...func(rune) bool) func(rune) bool {
return func(r rune) bool {
for _, cond := range s {
if cond(r) {
return true
}
}
return false
}
}
// IsSpace reports whether the rune is a space character as
// defined by Unicode's White Space property
func IsSpace(r rune) bool {
return unicode.IsSpace(r)
}
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