Merge pull request #493 from nevalang/regexp_submatcher

feat(std:regexp): Submatcher (+ example)

Makefile

@@ -3,7 +3,7 @@
 # build neva cli for host OS and put to the PATH
 .PHONY: install
 install:
-	@go build -ldflags="-s -w" cmd/cli/*.go && \
+	@go build -ldflags="-s -w" ./cmd/cli && \
 	rm -rf /usr/local/bin/neva && \
 	mv cli /usr/local/bin/neva
 

examples/10_regex_submatch/main.neva

@@ -0,0 +1,17 @@
+import { regexp }
+
+const { regex string = 'a(x*)b(y|z)c' }
+
+component Main(start) (stop) {
+    nodes {
+        Printer<any>
+
+        #bind(regex)
+        regexp.Submatcher
+    }
+    net {
+        :start -> ('-axxxbyc-' -> submatcher:data)
+        submatcher:res -> printer:data
+        printer:sig -> :stop
+    }
+}

internal/runtime/funcs/regexp_submatcher.go

@@ -0,0 +1,50 @@
+package funcs
+
+import (
+	"context"
+	"regexp"
+
+	"github.com/nevalang/neva/internal/runtime"
+)
+
+type regexpSubmatcher struct{}
+
+func (r regexpSubmatcher) Create(io runtime.FuncIO, cfgMsg runtime.Msg) (func(ctx context.Context), error) {
+	regex, err := regexp.Compile(cfgMsg.Str())
+	if err != nil {
+		return nil, err
+	}
+
+	dataIn, err := io.In.Port("data")
+	if err != nil {
+		return nil, err
+	}
+
+	resOut, err := io.Out.Port("res")
+	if err != nil {
+		return nil, err
+	}
+
+	return func(ctx context.Context) {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case dataMsg := <-dataIn:
+				resOut <- wrap(
+					regex.FindStringSubmatch(
+						dataMsg.String(),
+					),
+				)
+			}
+		}
+	}, nil
+}
+
+func wrap(ss []string) runtime.Msg {
+	msgs := make([]runtime.Msg, 0, len(ss))
+	for _, s := range ss {
+		msgs = append(msgs, runtime.NewStrMsg(s))
+	}
+	return runtime.NewListMsg(msgs...)
+}

internal/runtime/funcs/registry.go

@@ -22,6 +22,7 @@ func CreatorRegistry() map[string]runtime.FuncCreator {
 		"line_printer": linePrinter{},
 		// math
 		"int_adder": intAdder{},
-		// parsing
+		// regexp
+		"regexp_submatcher": regexpSubmatcher{},
 	}
 }

pkg/version.go

@@ -1,4 +1,4 @@
 package pkg
 
 // Version is the current version of the language and stdlib
-var Version = "0.9.0" //nolint:gochecknoglobals
+var Version = "0.10.0" //nolint:gochecknoglobals

std/regexp/regexp.neva

@@ -0,0 +1,3 @@
+// bind regexp string
+#extern(regexp_submatcher)
+pub component Submatcher(data string) (res list<string>)