hcl/zcl/zclsyntax/peeker.go

84 lines
1.6 KiB
Go

package zclsyntax
import (
"github.com/zclconf/go-zcl/zcl"
)
type peeker struct {
Tokens Tokens
NextIndex int
IncludeComments bool
IncludeNewlinesStack []bool
}
func newPeeker(tokens Tokens, includeComments bool) *peeker {
return &peeker{
Tokens: tokens,
IncludeComments: includeComments,
IncludeNewlinesStack: []bool{true},
}
}
func (p *peeker) Peek() Token {
ret, _ := p.nextToken()
return ret
}
func (p *peeker) Read() Token {
ret, nextIdx := p.nextToken()
p.NextIndex = nextIdx
return ret
}
func (p *peeker) NextRange() zcl.Range {
return p.Peek().Range
}
func (p *peeker) PrevRange() zcl.Range {
if p.NextIndex == 0 {
return p.NextRange()
}
return p.Tokens[p.NextIndex-1].Range
}
func (p *peeker) nextToken() (Token, int) {
for i := p.NextIndex; i < len(p.Tokens); i++ {
tok := p.Tokens[i]
switch tok.Type {
case TokenComment:
if !p.IncludeComments {
continue
}
case TokenNewline:
if !p.includingNewlines() {
continue
}
}
return tok, i + 1
}
// if we fall out here then we'll return the EOF token, and leave
// our index pointed off the end of the array so we'll keep
// returning EOF in future too.
return p.Tokens[len(p.Tokens)-1], len(p.Tokens)
}
func (p *peeker) includingNewlines() bool {
return p.IncludeNewlinesStack[len(p.IncludeNewlinesStack)-1]
}
func (p *peeker) PushIncludeNewlines(include bool) {
p.IncludeNewlinesStack = append(p.IncludeNewlinesStack, include)
}
func (p *peeker) PopIncludeNewlines() bool {
stack := p.IncludeNewlinesStack
remain, ret := stack[:len(stack)-1], stack[len(stack)-1]
p.IncludeNewlinesStack = remain
return ret
}