func (b *Builder) Parse(name string, l lex.Lexer) (ast *AST, err error) {
ctx := &builderCtx{
ParseName: name,
Lexer: l,
Root: NewRootNode(),
Tokens: [3]lex.LexItem{},
FrameStack: util.NewStack(5),
Frames: util.NewStack(5),
}
defer func() {
if ctx.Error != nil {
err = ctx.Error
ast = nil
// don't let the panic propagate
recover()
}
}()
b.Start(ctx)
b.ParseStatements(ctx)
return &AST{
Name: name,
Root: ctx.Root,
}, nil
}
// NewState creates a new State struct
func NewState() *State {
st := &State{
opidx: 0,
pc: NewByteCode(),
stack: util.NewStack(5),
markstack: util.NewStack(5),
framestack: util.NewStack(5),
frames: util.NewStack(5),
vars: make(Vars),
warn: os.Stderr,
}
st.Pushmark()
st.PushFrame()
return st
}