Working on multi-line statements

cmdlang/ast.go

@@ -2,6 +2,7 @@ package cmdlang
 
 import (
 	"github.com/alecthomas/participle/v2"
+	"github.com/alecthomas/participle/v2/lexer"
 	"io"
 )
 
@@ -12,8 +13,8 @@ type astLiteral struct {
 
 type astCmdArg struct {
 	Literal *astLiteral  `parser:"@@"`
-	Var     *string      `parser:"| '$' @Ident"`
+	Var     *string      `parser:"| DOLLAR @Ident"`
-	Sub     *astPipeline `parser:"| '(' @@ ')'"`
+	Sub     *astPipeline `parser:"| LP @@ RP"`
 }
 
 type astCmd struct {
@@ -23,15 +24,33 @@ type astCmd struct {
 
 type astPipeline struct {
 	First *astCmd   `parser:"@@"`
-	Rest  []*astCmd `parser:"( '|' @@ )*"`
+	Rest  []*astCmd `parser:"( PIPE @@ )*"`
 }
 
 type astStatements struct {
 	First *astPipeline   `parser:"@@"`
-	Rest  []*astPipeline `parser:"( ';' @@ )*"` // TODO: also add support for newlines
+	Rest  []*astPipeline `parser:"( (SEMICL | NL)+ @@ )*"` // TODO: also add support for newlines
 }
 
-var parser = participle.MustBuild[astStatements]()
+type astBlock struct {
+	Statements *astStatements `parser:"'{'  "`
+}
+
+var scanner = lexer.MustStateful(lexer.Rules{
+	"Root": {
+		{"Whitespace", `[ ]`, nil},
+		{"NL", `\n\s*`, nil},
+		{"String", `"(\\"|[^"])*"`, nil},
+		{"DOLLAR", `\$`, nil},
+		{"LP", `\(`, nil},
+		{"RP", `\)`, nil},
+		{"SEMICL", `;`, nil},
+		{"PIPE", `\|`, nil},
+		{"Ident", `\w+`, nil},
+	},
+})
+var parser = participle.MustBuild[astStatements](participle.Lexer(scanner),
+	participle.Elide("Whitespace"))
 
 func parse(r io.Reader) (*astStatements, error) {
 	return parser.Parse("test", r)

cmdlang/builtins.go

@@ -11,7 +11,9 @@ import (
 
 func echoBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 	if len(args.args) == 0 {
-		return strObject(""), nil
+		if _, err := fmt.Fprintln(args.inst.Out()); err != nil {
+			return nil, err
+		}
 	}
 
 	var line strings.Builder
@@ -21,7 +23,10 @@ func echoBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 		}
 	}
 
-	return strObject(line.String()), nil
+	if _, err := fmt.Fprintln(args.inst.Out(), line.String()); err != nil {
+		return nil, err
+	}
+	return nil, nil
 }
 
 func setBuiltin(ctx context.Context, args invocationArgs) (object, error) {

cmdlang/env.go

@@ -6,18 +6,10 @@ import (
 
 type evalCtx struct {
 	parent   *evalCtx
-	currentStream stream
 	commands map[string]invokable
 	vars     map[string]object
 }
 
-func (ec *evalCtx) withCurrentStream(s stream) *evalCtx {
-	return &evalCtx{
-		parent:        ec,
-		currentStream: s,
-	}
-}
-
 func (ec *evalCtx) addCmd(name string, inv invokable) {
 	if ec.commands == nil {
 		ec.commands = make(map[string]invokable)

cmdlang/eval.go

@@ -10,6 +10,7 @@ import (
 )
 
 type evaluator struct {
+	inst *Inst
 }
 
 func (e evaluator) evalStatement(ctx context.Context, ec *evalCtx, n *astStatements) (object, error) {
@@ -39,7 +40,7 @@ func (e evaluator) evalStatement(ctx context.Context, ec *evalCtx, n *astStateme
 }
 
 func (e evaluator) evalPipeline(ctx context.Context, ec *evalCtx, n *astPipeline) (object, error) {
-	res, err := e.evalCmd(ctx, ec, n.First)
+	res, err := e.evalCmd(ctx, ec, nil, n.First)
 	if err != nil {
 		return nil, err
 	}
@@ -49,7 +50,7 @@ func (e evaluator) evalPipeline(ctx context.Context, ec *evalCtx, n *astPipeline
 
 	// Command is a pipeline, so build it out
 	for _, rest := range n.Rest {
-		out, err := e.evalCmd(ctx, ec.withCurrentStream(asStream(res)), rest)
+		out, err := e.evalCmd(ctx, ec, asStream(res), rest)
 		if err != nil {
 			return nil, err
 		}
@@ -58,7 +59,7 @@ func (e evaluator) evalPipeline(ctx context.Context, ec *evalCtx, n *astPipeline
 	return res, nil
 }
 
-func (e evaluator) evalCmd(ctx context.Context, ec *evalCtx, ast *astCmd) (object, error) {
+func (e evaluator) evalCmd(ctx context.Context, ec *evalCtx, currentStream stream, ast *astCmd) (object, error) {
 	cmd, err := ec.lookupCmd(ast.Name)
 	if err != nil {
 		return nil, err
@@ -71,13 +72,13 @@ func (e evaluator) evalCmd(ctx context.Context, ec *evalCtx, ast *astCmd) (objec
 		return nil, err
 	}
 
-	invArgs := invocationArgs{ec: ec, args: args}
+	invArgs := invocationArgs{ec: ec, inst: e.inst, args: args, currentStream: currentStream}
 
-	if ec.currentStream != nil {
+	if currentStream != nil {
 		if si, ok := cmd.(streamInvokable); ok {
-			return si.invokeWithStream(ctx, ec.currentStream, invArgs)
+			return si.invokeWithStream(ctx, currentStream, invArgs)
 		} else {
-			if err := ec.currentStream.close(); err != nil {
+			if err := currentStream.close(); err != nil {
 				return nil, err
 			}
 		}

cmdlang/inst.go

@@ -47,6 +47,13 @@ func New(opts ...InstOption) *Inst {
 	return inst
 }
 
+func (inst *Inst) Out() io.Writer {
+	if inst.out == nil {
+		return os.Stdout
+	}
+	return inst.out
+}
+
 func (inst *Inst) Eval(ctx context.Context, expr string) (any, error) {
 	res, err := inst.eval(ctx, expr)
 	if err != nil {
@@ -67,7 +74,7 @@ func (inst *Inst) eval(ctx context.Context, expr string) (object, error) {
 		return nil, err
 	}
 
-	eval := evaluator{}
+	eval := evaluator{inst: inst}
 
 	return eval.evalStatement(ctx, inst.rootEC, ast)
 }
@@ -83,6 +90,10 @@ 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 nil:
+		if _, err = fmt.Fprintln(inst.out, "(nil)"); err != nil {
+			return err
+		}
 	case stream:
 		return forEach(v, func(o object, _ int) error { return inst.display(ctx, o) })
 	default:

cmdlang/inst_test.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"github.com/lmika/cmdlang-proto/cmdlang"
 	"github.com/stretchr/testify/assert"
+	"strings"
 	"testing"
 )
 
@@ -17,14 +18,14 @@ func TestInst_Eval(t *testing.T) {
 		{desc: "simple string", expr: `firstarg "hello"`, want: "hello"},
 
 		// Sub-expressions
-		{desc: "sub expression 1", expr: `firstarg (echo "hello")`, want: "hello"},
+		{desc: "sub expression 1", expr: `firstarg (sjoin "hello")`, want: "hello"},
-		{desc: "sub expression 2", expr: `firstarg (echo "hello " "world")`, want: "hello world"},
+		{desc: "sub expression 2", expr: `firstarg (sjoin "hello " "world")`, want: "hello world"},
-		{desc: "sub expression 3", expr: `firstarg (echo "hello" (echo " ") (echo "world"))`, want: "hello world"},
+		{desc: "sub expression 3", expr: `firstarg (sjoin "hello" (sjoin " ") (sjoin "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"},
+		{desc: "var 3", expr: `firstarg (sjoin $bee " " $bee " " $bee)`, want: "buzz buzz buzz"},
 
 		// Pipeline
 		{desc: "pipe 1", expr: `pipe "aye" "bee" "see" | joinpipe`, want: "aye,bee,see"},
@@ -37,6 +38,8 @@ func TestInst_Eval(t *testing.T) {
 		{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"},
+
+		{desc: "multi-line 1", expr: "echo \"Hello\" \n echo \"world\"", want: "world"},
 	}
 
 	for _, tt := range tests {
@@ -53,8 +56,7 @@ func TestInst_Eval(t *testing.T) {
 	}
 }
 
-func TestInst_Builtins(t *testing.T) {
+func TestInst_Builtins_Echo(t *testing.T) {
-	t.Run("echo", func(t *testing.T) {
 	tests := []struct {
 		desc string
 		expr string
@@ -64,6 +66,7 @@ func TestInst_Builtins(t *testing.T) {
 		{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"},
+		{desc: "multi-line 1", expr: joinLines(`echo "Hello"`, `echo "world"`), want: "Hello\nworld"},
 	}
 
 	for _, tt := range tests {
@@ -78,5 +81,8 @@ func TestInst_Builtins(t *testing.T) {
 			assert.Equal(t, tt.want, outW.String())
 		})
 	}
-	})
+}
+
+func joinLines(ls ...string) string {
+	return strings.Join(ls, "\n")
 }

cmdlang/objs.go

@@ -31,6 +31,7 @@ func toGoValue(obj object) (interface{}, bool) {
 type invocationArgs struct {
 	inst          *Inst
 	ec            *evalCtx
+	currentStream stream
 	args          []object
 }
 

cmdlang/testbuiltins_test.go

@@ -2,6 +2,7 @@ package cmdlang
 
 import (
 	"context"
+	"fmt"
 	"strings"
 )
 
@@ -12,6 +13,21 @@ func WithTestBuiltin() InstOption {
 			return args.args[0], nil
 		}))
 
+		i.rootEC.addCmd("sjoin", invokableFunc(func(ctx context.Context, args invocationArgs) (object, error) {
+			if len(args.args) == 0 {
+				return strObject(""), nil
+			}
+
+			var line strings.Builder
+			for _, arg := range args.args {
+				if s, ok := arg.(fmt.Stringer); ok {
+					line.WriteString(s.String())
+				}
+			}
+
+			return strObject(line.String()), nil
+		}))
+
 		i.rootEC.addCmd("pipe", invokableFunc(func(ctx context.Context, args invocationArgs) (object, error) {
 			return &listIterStream{
 				list: args.args,