Move examples to examples dir, now LoadJsonFile() also returns err

* Move examples from cmd to examples dir
* Update Makefile
* LoadJsonFile() dies in-place on read or parse error which is not correct
* LoadJsonFile() wastes Instance map, now it returns its own map and error if any

Makefile

@@ -7,6 +7,8 @@ BINARY=${MYNAME}
 UNIX_BINARY=${MYNAME}
 WINDOWS_BINARY=${MYNAME}.exe
 RMCMD=rm -rf
+EXAMPLE01=01-LoadJsonFile
+EXAMPLE02=02-TestLuaScript
 
 # На windows имя бинарника может зависеть не только от платформы, но и от выбранной цели, для linux-а суффикс .exe
 # не нужен
@@ -58,19 +60,19 @@ clean:
 ifeq ($(OS),Windows_NT)
 ifeq ($(SHELL),sh.exe)
 #	# Vanilla cmd.exe / powershell.
-	if exist 01-LoadJsonFile.exe ${RMCMD} 01-LoadJsonFile.exe
+	if exist ${EXAMPLE01}.exe ${RMCMD} ${EXAMPLE01}.exe
-	if exist 01-LoadJsonFile ${RMCMD} 01-LoadJsonFile
+	if exist ${EXAMPLE01} ${RMCMD} ${EXAMPLE01}
-	if exist 02-TestLuaScript.exe ${RMCMD} 02-TestLuaScript.exe
+	if exist ${EXAMPLE02}.exe ${RMCMD} ${EXAMPLE02}.exe
-	if exist 02-TestLuaScript ${RMCMD} 02-TestLuaScript
+	if exist ${EXAMPLE02} ${RMCMD} ${EXAMPLE02}
 else  # not ifeq ($(SHELL),sh.exe)
-	${RMCMD} ./01-LoadJsonFile.exe
+	${RMCMD} ./${EXAMPLE01}.exe
-	${RMCMD} ./01-LoadJsonFile
+	${RMCMD} ./${EXAMPLE01}
-	${RMCMD} ./02-TestLuaScript.exe
+	${RMCMD} ./${EXAMPLE02}.exe
-	${RMCMD} ./02-TestLuaScript
+	${RMCMD} ./${EXAMPLE02}
 endif # ifeq ($(SHELL),sh.exe)
 else  # not ifeq ($(OS),Windows_NT)
-	${RMCMD} ./01-LoadJsonFile
+	${RMCMD} ${EXAMPLE01}
-	${RMCMD} ./02-TestLuaScript
+	${RMCMD} ${EXAMPLE02}
 endif
 
 
@@ -80,23 +82,23 @@ upgrade:
 	go mod vendor
 
 
-01-LoadJsonFile: clean
+${EXAMPLE01}: clean
 ifeq ($(OS),Windows_NT)
 # Looks like on windows gnu make explicitly set SHELL to sh.exe, if it was not set.
 ifeq ($(SHELL), sh.exe)
 #       # Vanilla cmd.exe / powershell.
 	SET "CGO_ENABLED=0"
-	go build ${BUILDOPTS} -o 01-LoadJsonFile.exe ./cmd/01-LoadJsonFile
+	go build ${BUILDOPTS} -o ${EXAMPLE01}.exe ./cmd/${EXAMPLE01}
 else ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 #       # git-bash
-	CGO_ENABLED=0 go build ${BUILDOPTS} -o 01-LoadJsonFile.exe ./cmd/01-LoadJsonFile
+	CGO_ENABLED=0 go build ${BUILDOPTS} -o ${EXAMPLE01}.exe ./cmd/${EXAMPLE01}
 else  # not ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 #       # Some other shell.
 #       # TODO: handle it.
 	$(info "-- Dunno how to handle this shell: ${SHELL}")
 endif # ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 else  # not  ($(OS),Windows_NT)
-	CGO_ENABLED=0 go build ${BUILDOPTS} -o 01-LoadJsonFile ./cmd/01-LoadJsonFile
+	CGO_ENABLED=0 go build ${BUILDOPTS} -o ${EXAMPLE01} ./cmd/${EXAMPLE01}
 endif # ifeq ($(OS),Windows_NT)
 
 
@@ -106,17 +108,18 @@ ifeq ($(OS),Windows_NT)
 ifeq ($(SHELL), sh.exe)
 #       # Vanilla cmd.exe / powershell.
 	SET "CGO_ENABLED=0"
-	go build ${BUILDOPTS} -o 02-TestLuaScript.exe ./cmd/02-TestLuaScript
+	go build ${BUILDOPTS} -o ${EXAMPLE02}.exe ./cmd/${EXAMPLE02}
 else ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 #       # git-bash
-	CGO_ENABLED=0 go build ${BUILDOPTS} -o 02-TestLuaScript.exe ./cmd/02-TestLuaScript
+	CGO_ENABLED=0 go build ${BUILDOPTS} -o ${EXAMPLE02}.exe ./cmd/${EXAMPLE02}
 else  # not ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 #       # Some other shell.
 #       # TODO: handle it.
 	$(info "-- Dunno how to handle this shell: ${SHELL}")
 endif # ifeq (,$(findstring(Git/usr/bin/sh.exe, $(SHELL))))
 else  # not  ($(OS),Windows_NT)
-	CGO_ENABLED=0 go build ${BUILDOPTS} -o 02-TestLuaScript ./cmd/02-TestLuaScript
+	CGO_ENABLED=0 go build ${BUILDOPTS} -o ${EXAMPLE02} ./cmd/${EXAMPLE02}
 endif # ifeq ($(OS),Windows_NT)
 
+
 # vim: set ft=make noet ai ts=4 sw=4 sts=4:

cmd/01-LoadJsonFile/main.go

@@ -1,21 +0,0 @@
-package main
-
-import (
-	"doll/internal/doll"
-	"doll/internal/log"
-	"os"
-
-	"github.com/davecgh/go-spew/spew"
-)
-
-func main() {
-	log.Init("info", os.Stderr)
-	log.Info("loading config.json")
-
-	data := doll.LoadJsonFile("test_data/config.json")
-
-	log.Info("data fron config.json is")
-	spew.Dump(data)
-}
-
-/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

cmd/02-TestLuaScript/main.go

@@ -1,34 +0,0 @@
-package main
-
-import (
-	"doll/internal/log"
-	"os"
-
-	lua "github.com/yuin/gopher-lua"
-)
-
-func main() {
-	log.Init("info", os.Stderr)
-
-	L := lua.NewState()
-	defer L.Close()
-
-	// Load the Lua script file.
-	log.Info("Loading ./test_data/01-test.lua")
-
-	luaCode, err := os.ReadFile("./test_data/01-test.lua")
-
-	if err != nil {
-		log.Errorf("Error reading Lua file: %s", err)
-
-		os.Exit(1)
-	}
-
-	if err := L.DoString(string(luaCode)); err != nil {
-		log.Errorf("Error evaluating Lua code: %s", err)
-
-		os.Exit(1)
-	}
-}
-
-/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

example_data/02-test.lua

@@ -0,0 +1,3 @@
+print ("Hello World!")
+
+-- vim: set ft=lua noet ai ts=4 sw=4 sts=4:

examples/01-LoadJsonFile/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"doll/internal/doll"
+	"doll/internal/log"
+	"os"
+
+	"github.com/davecgh/go-spew/spew"
+)
+
+func main() {
+	// Init log subsystem.
+	log.Init("info", os.Stderr)
+
+	file := "example_data/01-config.json"
+
+	// Load the Lua script file.
+	log.Infof("Loading %s", file)
+
+	data, err := doll.LoadJsonFile(file)
+
+	if err != nil {
+		log.Fatalf("Unable to unmarshal %s to map: %s", file, err)
+	}
+
+	log.Infof("Map unmarshalled from %s", file)
+
+	spew.Dump(data)
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

examples/02-TestLuaScript/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"doll/internal/log"
+	"os"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+func main() {
+	// Init log subsystem.
+	log.Init("info", os.Stderr)
+
+	file := "example_data/02-test.lua"
+
+	// Load the Lua script file.
+	log.Infof("Loading %s", file)
+
+	// We can execute script directly via L.DoFile("./example_data/02-test.lua") but in practice we'll get scripts as
+	// strings - snippets from templates - so, testing/checking how it works is not use for project.
+	luaCode, err := os.ReadFile(file)
+
+	if err != nil {
+		log.Fatalf("Error reading Lua file %s: %s", file, err)
+	}
+
+	log.Info("Creating new Lua state")
+	L := lua.NewState()
+	defer L.Close()
+
+	log.Info("Evaluating Lua code")
+	if err := L.DoString(string(luaCode)); err != nil {
+		log.Fatalf("Error evaluating Lua code: %s", err)
+	}
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

internal/doll/jsonfile.go

@@ -1,30 +1,30 @@
 package doll
 
 import (
-	"doll/internal/log"
 	"encoding/json"
+	"fmt"
 	"os"
 )
 
 // LoadJsonFile loads data from json to Instance global variable map.
-func LoadJsonFile(file string) map[string]any {
+func LoadJsonFile(file string) (map[string]any, error) {
 	var (
-		err  error
+		err   error
-		data []byte
+		data  []byte
+		myMap map[string]any
 	)
 
 	data, err = os.ReadFile(file)
 
 	if err != nil {
-		log.Fatalf("Unable to load %s: %s", file, err)
+		return myMap, fmt.Errorf("Unable to load %s: %w", file, err)
 	}
 
-	err = json.Unmarshal([]byte(data), &Instance)
+	if err = json.Unmarshal([]byte(data), &myMap); err != nil {
-	if err != nil {
+		return myMap, fmt.Errorf("Unable to unmarshal JSON data from %s: %w", file, err)
-		log.Fatalf("Unable to marshal JSON data from %s: %s", file, err)
 	}
 
-	return Instance
+	return myMap, err
 }
 
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

test_data/01-test.lua

@@ -1,3 +0,0 @@
-print ("Hello World!")
-
--- vim: set ft=go noet ai ts=4 sw=4 sts=4: