blob: 57a5fd2bdc91e542e9a051fea89b794333c27024 [file] [log] [blame]
package hclwrite
import (
"bytes"
"io"
"github.com/apparentlymart/go-textseg/v13/textseg"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/hclsyntax"
)
// Token is a single sequence of bytes annotated with a type. It is similar
// in purpose to hclsyntax.Token, but discards the source position information
// since that is not useful in code generation.
type Token struct {
Type hclsyntax.TokenType
Bytes []byte
// We record the number of spaces before each token so that we can
// reproduce the exact layout of the original file when we're making
// surgical changes in-place. When _new_ code is created it will always
// be in the canonical style, but we preserve layout of existing code.
SpacesBefore int
}
// asHCLSyntax returns the receiver expressed as an incomplete hclsyntax.Token.
// A complete token is not possible since we don't have source location
// information here, and so this method is unexported so we can be sure it will
// only be used for internal purposes where we know the range isn't important.
//
// This is primarily intended to allow us to re-use certain functionality from
// hclsyntax rather than re-implementing it against our own token type here.
func (t *Token) asHCLSyntax() hclsyntax.Token {
return hclsyntax.Token{
Type: t.Type,
Bytes: t.Bytes,
Range: hcl.Range{
Filename: "<invalid>",
},
}
}
// Tokens is a flat list of tokens.
type Tokens []*Token
func (ts Tokens) Bytes() []byte {
buf := &bytes.Buffer{}
ts.WriteTo(buf)
return buf.Bytes()
}
func (ts Tokens) testValue() string {
return string(ts.Bytes())
}
// Columns returns the number of columns (grapheme clusters) the token sequence
// occupies. The result is not meaningful if there are newline or single-line
// comment tokens in the sequence.
func (ts Tokens) Columns() int {
ret := 0
for _, token := range ts {
ret += token.SpacesBefore // spaces are always worth one column each
ct, _ := textseg.TokenCount(token.Bytes, textseg.ScanGraphemeClusters)
ret += ct
}
return ret
}
// WriteTo takes an io.Writer and writes the bytes for each token to it,
// along with the spacing that separates each token. In other words, this
// allows serializing the tokens to a file or other such byte stream.
func (ts Tokens) WriteTo(wr io.Writer) (int64, error) {
// We know we're going to be writing a lot of small chunks of repeated
// space characters, so we'll prepare a buffer of these that we can
// easily pass to wr.Write without any further allocation.
spaces := make([]byte, 40)
for i := range spaces {
spaces[i] = ' '
}
var n int64
var err error
for _, token := range ts {
if err != nil {
return n, err
}
for spacesBefore := token.SpacesBefore; spacesBefore > 0; spacesBefore -= len(spaces) {
thisChunk := spacesBefore
if thisChunk > len(spaces) {
thisChunk = len(spaces)
}
var thisN int
thisN, err = wr.Write(spaces[:thisChunk])
n += int64(thisN)
if err != nil {
return n, err
}
}
var thisN int
thisN, err = wr.Write(token.Bytes)
n += int64(thisN)
}
return n, err
}
func (ts Tokens) walkChildNodes(w internalWalkFunc) {
// Unstructured tokens have no child nodes
}
func (ts Tokens) BuildTokens(to Tokens) Tokens {
return append(to, ts...)
}
// ObjectAttrTokens represents the raw tokens for the name and value of
// one attribute in an object constructor expression.
//
// This is defined primarily for use with function TokensForObject. See
// that function's documentation for more information.
type ObjectAttrTokens struct {
Name Tokens
Value Tokens
}
func newIdentToken(name string) *Token {
return &Token{
Type: hclsyntax.TokenIdent,
Bytes: []byte(name),
}
}