Started writing some tests

cmdlang/ast.go

@@ -26,8 +26,13 @@ type astPipeline struct {
 	Rest  []*astCmd `parser:"( '|' @@ )*"`
 }
 
-var parser = participle.MustBuild[astPipeline]()
+type astStatements struct {
+	First *astPipeline   `parser:"@@"`
+	Rest  []*astPipeline `parser:"( ';' @@ )*"` // TODO: also add support for newlines
+}
 
-func parse(r io.Reader) (*astPipeline, error) {
+var parser = participle.MustBuild[astStatements]()
+
+func parse(r io.Reader) (*astStatements, error) {
 	return parser.Parse("test", r)
 }

cmdlang/builtins.go

@@ -3,7 +3,6 @@ package cmdlang
 import (
 	"bufio"
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -12,7 +11,7 @@ import (
 
 func echoBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 	if len(args.args) == 0 {
-		return asStream(""), nil
+		return asStream(strObject("")), nil
 	}
 
 	var line strings.Builder
@@ -22,7 +21,7 @@ func echoBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 		}
 	}
 
-	return asStream(line.String()), nil
+	return asStream(strObject(line.String())), nil
 }
 
 func setBuiltin(ctx context.Context, args invocationArgs) (object, error) {
@@ -47,11 +46,11 @@ func toUpperBuiltin(ctx context.Context, inStream stream, args invocationArgs) (
 	return mapFilterStream{
 		in: inStream,
 		mapFn: func(x object) (object, bool) {
-			s, ok := x.(string)
+			s, ok := x.(strObject)
 			if !ok {
 				return nil, false
 			}
-			return strings.ToUpper(s), true
+			return strObject(strings.ToUpper(string(s))), true
 		},
 	}, nil
 }
@@ -75,6 +74,10 @@ type fileLinesStream struct {
 	scnr     *bufio.Scanner
 }
 
+func (f *fileLinesStream) String() string {
+	return fmt.Sprintf("fileLinesStream{file: %v}", f.filename)
+}
+
 func (f *fileLinesStream) next() (object, error) {
 	var err error
 
@@ -88,7 +91,7 @@ func (f *fileLinesStream) next() (object, error) {
 	}
 
 	if f.scnr.Scan() {
-		return f.scnr.Text(), nil
+		return strObject(f.scnr.Text()), nil
 	}
 	if f.scnr.Err() == nil {
 		return nil, io.EOF
@@ -103,6 +106,7 @@ func (f *fileLinesStream) close() error {
 	return nil
 }
 
+/*
 func errorTestBuiltin(ctx context.Context, inStream stream, args invocationArgs) (object, error) {
 	return &timeBombStream{inStream, 2}, nil
 }
@@ -123,3 +127,4 @@ func (ms *timeBombStream) next() (object, error) {
 func (ms *timeBombStream) close() error {
 	return ms.in.close()
 }
+*/

cmdlang/eval.go

@@ -12,7 +12,33 @@ import (
 type evaluator struct {
 }
 
-func (e evaluator) evaluate(ctx context.Context, ec *evalCtx, n *astPipeline) (object, error) {
+func (e evaluator) evalStatement(ctx context.Context, ec *evalCtx, n *astStatements) (object, error) {
+	res, err := e.evalPipeline(ctx, ec, n.First)
+	if err != nil {
+		return nil, err
+	}
+	if len(n.Rest) == 0 {
+		return res, nil
+	}
+
+	for _, rest := range n.Rest {
+		// Discard and close unused streams
+		if s, isStream := res.(stream); isStream {
+			if err := s.close(); err != nil {
+				return nil, err
+			}
+		}
+
+		out, err := e.evalPipeline(ctx, ec, rest)
+		if err != nil {
+			return nil, err
+		}
+		res = out
+	}
+	return res, nil
+}
+
+func (e evaluator) evalPipeline(ctx context.Context, ec *evalCtx, n *astPipeline) (object, error) {
 	res, err := e.evalCmd(ctx, ec, n.First)
 	if err != nil {
 		return nil, err
@@ -81,31 +107,31 @@ func (e evaluator) evalLiteral(ctx context.Context, ec *evalCtx, n *astLiteral)
 	case n.Str != nil:
 		uq, err := strconv.Unquote(*n.Str)
 		if err != nil {
-			return "", err
+			return nil, err
 		}
 		return strObject(uq), nil
 	case n.Ident != nil:
 		return strObject(*n.Ident), nil
 	}
-	return "", errors.New("unhandled literal type")
+	return nil, errors.New("unhandled literal type")
 }
 
 func (e evaluator) evalSub(ctx context.Context, ec *evalCtx, n *astPipeline) (object, error) {
-	pipelineRes, err := e.evaluate(ctx, ec, n)
+	pipelineRes, err := e.evalPipeline(ctx, ec, n)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	switch v := pipelineRes.(type) {
 	case stream:
 		// TODO: use proper lists here, not a string join
 		sb := strings.Builder{}
-		if err := forEach(v, func(o object) error {
+		if err := forEach(v, func(o object, _ int) error {
 			// TODO: use o.String()
 			sb.WriteString(fmt.Sprint(o))
 			return nil
 		}); err != nil {
-			return "", err
+			return nil, err
 		}
 
 		return strObject(sb.String()), nil

cmdlang/inst.go

@@ -2,43 +2,78 @@ package cmdlang
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"io"
+	"os"
 	"strings"
 )
 
 type Inst struct {
+	out io.Writer
+
 	rootEC *evalCtx
 }
 
-func New() *Inst {
+type InstOption func(*Inst)
+
+func WithOut(out io.Writer) InstOption {
+	return func(i *Inst) {
+		i.out = out
+	}
+}
+
+func New(opts ...InstOption) *Inst {
 	rootEC := evalCtx{}
+
 	rootEC.addCmd("echo", invokableFunc(echoBuiltin))
 	rootEC.addCmd("set", invokableFunc(setBuiltin))
 	rootEC.addCmd("toUpper", invokableStreamFunc(toUpperBuiltin))
 	rootEC.addCmd("cat", invokableFunc(catBuiltin))
 
-	rootEC.addCmd("testTimebomb", invokableStreamFunc(errorTestBuiltin))
+	//rootEC.addCmd("testTimebomb", invokableStreamFunc(errorTestBuiltin))
 
 	rootEC.setVar("hello", strObject("world"))
 
-	return &Inst{
+	inst := &Inst{
+		out:    os.Stdout,
 		rootEC: &rootEC,
 	}
+
+	for _, opt := range opts {
+		opt(inst)
+	}
+
+	return inst
 }
 
-// TODO: return value?
 func (inst *Inst) Eval(ctx context.Context, expr string) (any, error) {
+	res, err := inst.eval(ctx, expr)
+	if err != nil {
+		return nil, err
+	}
+
+	goRes, ok := toGoValue(res)
+	if !ok {
+		return nil, errors.New("result not convertable to go")
+	}
+
+	return goRes, nil
+}
+
+func (inst *Inst) eval(ctx context.Context, expr string) (object, error) {
 	ast, err := parse(strings.NewReader(expr))
 	if err != nil {
 		return nil, err
 	}
 
 	eval := evaluator{}
-	return eval.evaluate(ctx, inst.rootEC, ast)
+
+	return eval.evalStatement(ctx, inst.rootEC, ast)
 }
 
 func (inst *Inst) EvalAndDisplay(ctx context.Context, expr string) error {
-	res, err := inst.Eval(ctx, expr)
+	res, err := inst.eval(ctx, expr)
 	if err != nil {
 		return err
 	}
@@ -49,9 +84,11 @@ func (inst *Inst) EvalAndDisplay(ctx context.Context, expr string) error {
 func (inst *Inst) display(ctx context.Context, res object) (err error) {
 	switch v := res.(type) {
 	case stream:
-		return forEach(v, func(o object) error { return inst.display(ctx, o) })
-	case string:
-		fmt.Println(v)
+		return forEach(v, func(o object, _ int) error { return inst.display(ctx, o) })
+	default:
+		if _, err = fmt.Fprintln(inst.out, v.String()); err != nil {
+			return err
+		}
 	}
 	return nil
 }

cmdlang/inst_test.go

@@ -0,0 +1,81 @@
+package cmdlang_test
+
+import (
+	"bytes"
+	"context"
+	"github.com/lmika/cmdlang-proto/cmdlang"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestInst_Eval(t *testing.T) {
+	tests := []struct {
+		desc string
+		expr string
+		want string
+	}{
+		{desc: "simple string", expr: `firstarg "hello"`, want: "hello"},
+
+		// Sub-expressions
+		{desc: "sub expression 1", expr: `firstarg (echo "hello")`, want: "hello"},
+		{desc: "sub expression 2", expr: `firstarg (echo "hello " "world")`, want: "hello world"},
+		{desc: "sub expression 3", expr: `firstarg (echo "hello" (echo " ") (echo "world"))`, want: "hello world"},
+
+		// Variables
+		{desc: "var 1", expr: `firstarg $a`, want: "alpha"},
+		{desc: "var 2", expr: `firstarg $bee`, want: "buzz"},
+		{desc: "var 3", expr: `firstarg (echo $bee " " $bee " " $bee)`, want: "buzz buzz buzz"},
+
+		// Pipeline
+		{desc: "pipe 1", expr: `pipe "aye" "bee" "see" | joinpipe`, want: "aye,bee,see"},
+		{desc: "pipe 2", expr: `pipe "aye" "bee" "see" | toUpper | joinpipe`, want: "AYE,BEE,SEE"},
+
+		{desc: "ignored pipe", expr: `pipe "aye" "bee" "see" | firstarg "ignore me"`, want: "ignore me"}, // TODO: check for leaks
+
+		// Multi-statements
+		{desc: "multi 1", expr: `firstarg "hello" ; firstarg "world"`, want: "world"},
+		{desc: "multi 2", expr: `pipe "hello" | toUpper ; firstarg "world"`, want: "world"}, // TODO: assert for leaks
+		{desc: "multi 3", expr: `set new "this is new" ; firstarg $new`, want: "this is new"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			ctx := context.Background()
+			outW := bytes.NewBuffer(nil)
+
+			inst := cmdlang.New(cmdlang.WithOut(outW), cmdlang.WithTestBuiltin())
+			res, err := inst.Eval(ctx, tt.expr)
+
+			assert.NoError(t, err)
+			assert.Equal(t, tt.want, res)
+		})
+	}
+}
+
+func TestInst_Builtins(t *testing.T) {
+	t.Run("echo", func(t *testing.T) {
+		tests := []struct {
+			desc string
+			expr string
+			want string
+		}{
+			{desc: "no args", expr: `echo`, want: "\n"},
+			{desc: "single arg", expr: `echo "hello"`, want: "hello\n"},
+			{desc: "dual args", expr: `echo "hello " "world"`, want: "hello world\n"},
+			{desc: "args to singleton stream", expr: `echo "aye" "bee" "see" | toUpper`, want: "AYEBEESEE\n"},
+		}
+
+		for _, tt := range tests {
+			t.Run(tt.desc, func(t *testing.T) {
+				ctx := context.Background()
+				outW := bytes.NewBuffer(nil)
+
+				inst := cmdlang.New(cmdlang.WithOut(outW), cmdlang.WithTestBuiltin())
+				err := inst.EvalAndDisplay(ctx, tt.expr)
+
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, outW.String())
+			})
+		}
+	})
+}

cmdlang/objs.go

@@ -8,6 +8,7 @@ import (
 )
 
 type object interface {
+	String() string
 }
 
 type strObject string
@@ -16,7 +17,19 @@ func (s strObject) String() string {
 	return string(s)
 }
 
+func toGoValue(obj object) (interface{}, bool) {
+	switch v := obj.(type) {
+	case nil:
+		return nil, true
+	case strObject:
+		return string(v), true
+	}
+
+	return nil, false
+}
+
 type invocationArgs struct {
+	inst *Inst
 	ec   *evalCtx
 	args []object
 }

cmdlang/streams.go

@@ -2,6 +2,7 @@ package cmdlang
 
 import (
 	"errors"
+	"fmt"
 	"io"
 )
 
@@ -14,6 +15,8 @@ import (
 // It is the job of the final iterator to call close. Any steam that consumes from another stream must
 // implement this, and call close on the parent stream.
 type stream interface {
+	object
+
 	// next pulls the next object from the stream.  If an object is available, the result is the
 	// object and a nil error.  If no more objects are available, error returns io.EOF.
 	// Otherwise, an error is returned.
@@ -24,14 +27,16 @@ type stream interface {
 
 // forEach will iterate over all the items of a stream. The iterating function can return an error, which will
 // be returned as is. A stream that has consumed every item will return nil. The stream will automatically be closed.
-func forEach(s stream, f func(object) error) (err error) {
+func forEach(s stream, f func(object, int) error) (err error) {
 	defer s.close()
 
 	var sv object
+	i := 0
 	for sv, err = s.next(); err == nil; sv, err = s.next() {
-		if err := f(sv); err != nil {
+		if err := f(sv, i); err != nil {
 			return err
 		}
+		i += 1
 	}
 	if !errors.Is(err, io.EOF) {
 		return err
@@ -50,6 +55,10 @@ func asStream(v object) stream {
 
 type emptyStream struct{}
 
+func (s *emptyStream) String() string {
+	return "(nil)"
+}
+
 func (s emptyStream) next() (object, error) {
 	return nil, io.EOF
 }
@@ -57,10 +66,14 @@ func (s emptyStream) next() (object, error) {
 func (s emptyStream) close() error { return nil }
 
 type singletonStream struct {
-	t        any
+	t        object
 	consumed bool
 }
 
+func (s *singletonStream) String() string {
+	return s.t.String()
+}
+
 func (s *singletonStream) next() (object, error) {
 	if s.consumed {
 		return nil, io.EOF
@@ -71,11 +84,37 @@ func (s *singletonStream) next() (object, error) {
 
 func (s *singletonStream) close() error { return nil }
 
+type listIterStream struct {
+	list []object
+	cusr int
+}
+
+func (s *listIterStream) String() string {
+	return fmt.Sprintf("listIterStream{list: %v}", s.list)
+}
+
+func (s *listIterStream) next() (o object, err error) {
+	if s.cusr >= len(s.list) {
+		return nil, io.EOF
+	}
+
+	o = s.list[s.cusr]
+	s.cusr += 1
+
+	return o, nil
+}
+
+func (s *listIterStream) close() error { return nil }
+
 type mapFilterStream struct {
 	in    stream
 	mapFn func(x object) (object, bool)
 }
 
+func (ms mapFilterStream) String() string {
+	return fmt.Sprintf("mapFilterStream{in: %v}", ms.in)
+}
+
 func (ms mapFilterStream) next() (object, error) {
 	for {
 		u, err := ms.in.next()

cmdlang/testbuiltins_test.go

@@ -0,0 +1,38 @@
+package cmdlang
+
+import (
+	"context"
+	"strings"
+)
+
+// Builtins used for test
+func WithTestBuiltin() InstOption {
+	return func(i *Inst) {
+		i.rootEC.addCmd("firstarg", invokableFunc(func(ctx context.Context, args invocationArgs) (object, error) {
+			return args.args[0], nil
+		}))
+
+		i.rootEC.addCmd("pipe", invokableFunc(func(ctx context.Context, args invocationArgs) (object, error) {
+			return &listIterStream{
+				list: args.args,
+			}, nil
+		}))
+
+		i.rootEC.addCmd("joinpipe", invokableStreamFunc(func(ctx context.Context, inStream stream, args invocationArgs) (object, error) {
+			sb := strings.Builder{}
+			if err := forEach(inStream, func(o object, i int) error {
+				if i > 0 {
+					sb.WriteString(",")
+				}
+				sb.WriteString(o.String())
+				return nil
+			}); err != nil {
+				return nil, err
+			}
+			return strObject(sb.String()), nil
+		}))
+
+		i.rootEC.setVar("a", strObject("alpha"))
+		i.rootEC.setVar("bee", strObject("buzz"))
+	}
+}

go.mod

@@ -5,6 +5,10 @@ go 1.21.1
 require (
 	github.com/alecthomas/participle/v2 v2.1.1 // indirect
 	github.com/chzyer/readline v1.5.1 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/lmika/gopkgs v0.0.0-20240408110817-a02f6fc67d1f // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.9.0 // indirect
 	golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -4,7 +4,16 @@ github.com/chzyer/logex v1.2.1/go.mod h1:JLbx6lG2kDbNRFnfkgvh4eRJRPX1QCoOIWomwys
 github.com/chzyer/readline v1.5.1 h1:upd/6fQk4src78LMRzh5vItIt361/o4uq553V8B5sGI=
 github.com/chzyer/readline v1.5.1/go.mod h1:Eh+b79XXUwfKfcPLepksvw2tcLE/Ct21YObkaSkeBlk=
 github.com/chzyer/test v1.0.0/go.mod h1:2JlltgoNkt4TW/z9V/IzDdFaMTM2JPIi26O1pF38GC8=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/lmika/gopkgs v0.0.0-20240408110817-a02f6fc67d1f h1:tz68Lhc1oR15HVz69IGbtdukdH0x70kBDEvvj5pTXyE=
 github.com/lmika/gopkgs v0.0.0-20240408110817-a02f6fc67d1f/go.mod h1:zHQvhjGXRro/Xp2C9dbC+ZUpE0gL4GYW75x1lk7hwzI=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5 h1:y/woIyUBFbpQGKS0u1aHF/40WUDnek3fPOyD08H5Vng=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=