69 lines
1.4 KiB
Go
69 lines
1.4 KiB
Go
package cmdlang
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import (
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"context"
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"errors"
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"github.com/lmika/gopkgs/fp/slices"
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"strconv"
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)
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type evaluator struct {
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}
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func (e evaluator) evaluate(ctx context.Context, ec *evalCtx, n *astPipeline) (object, error) {
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res, err := e.evalCmd(ctx, ec, n.First)
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if err != nil {
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return nil, err
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}
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if len(n.Rest) == 0 {
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return res, nil
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}
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// Command is a pipeline, so build it out
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for _, rest := range n.Rest {
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out, err := e.evalCmd(ctx, ec.withCurrentStream(asStream(res)), rest)
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if err != nil {
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return nil, err
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}
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res = out
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}
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return res, nil
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}
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func (e evaluator) evalCmd(ctx context.Context, ec *evalCtx, ast *astCmd) (object, error) {
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cmd, err := ec.lookupCmd(ast.Name)
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if err != nil {
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return nil, err
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}
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args, err := slices.MapWithError(ast.Args, func(a astCmdArg) (string, error) {
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return e.evalArg(ctx, ec, a)
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})
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if err != nil {
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return nil, err
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}
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return cmd.invoke(ctx, invocationArgs{
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args: args,
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inStream: ec.currentStream,
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})
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}
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func (e evaluator) evalArg(ctx context.Context, ec *evalCtx, n astCmdArg) (string, error) {
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return e.evalLiteral(ctx, ec, n.Literal)
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}
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func (e evaluator) evalLiteral(ctx context.Context, ec *evalCtx, n astLiteral) (string, error) {
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switch {
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case n.Str != nil:
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uq, err := strconv.Unquote(*n.Str)
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if err != nil {
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return "", err
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}
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return uq, nil
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case n.Ident != nil:
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return *n.Ident, nil
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}
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return "", errors.New("unhandled literal type")
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}
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