go tree-sitter
Golang bindings for tree-sitter
Usage
Create a parser with that grammar:
import (
sitter "github.com/smacker/go-tree-sitter"
"github.com/smacker/go-tree-sitter/javascript"
)
parser := sitter.NewParser()
parser.SetLanguage(javascript.GetLanguage())Parse some code:
sourceCode := []byte("let a = 1")
tree := parser.Parse(nil, sourceCode)Inspect the syntax tree:
n := tree.RootNode()
fmt.Println(n) // (program (lexical_declaration (variable_declarator (identifier) (number))))
child := n.NamedChild(0)
fmt.Println(child.Type()) // lexical_declaration
fmt.Println(child.StartByte()) // 0
fmt.Println(child.EndByte()) // 9If your source code changes, you can update the syntax tree. This will take less time than the first parse.
// change 1 -> true
newText := []byte("let a = true")
tree.Edit(sitter.EditInput{
StartIndex: 8,
OldEndIndex: 9,
NewEndIndex: 12,
StartPoint: sitter.Point{
Row: 0,
Column: 8,
},
OldEndPoint: sitter.Point{
Row: 0,
Column: 9,
},
NewEndPoint: sitter.Point{
Row: 0,
Column: 12,
},
})
// check that it changed tree
assert.True(n.HasChanges())
assert.True(n.Child(0).HasChanges())
assert.False(n.Child(0).Child(0).HasChanges()) // left side of the tree didn't change
assert.True(n.Child(0).Child(1).HasChanges())
// generate new tree
newTree := parser.Parse(tree, newText)Development
Check if any updates for vendored files are available:
./vendor.sh check-updates
Update vendor files:
- modify
grammarsarray invendor.sh - run
./vendor.sh download. (This script requires Bash v5, not the v3 of recent Mac OS.)