adding quickfix library

quickfix/cmd/generate-fix/internal/generate.go

@@ -0,0 +1,88 @@
+package internal
+
+import (
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"os"
+	"path"
+)
+
+var (
+	useFloat    = flag.Bool("use-float", false, "By default, FIX float fields are represented as arbitrary-precision fixed-point decimal numbers.  Set to 'true' to instead generate FIX float fields as float64 values.")
+	useUDecimal = flag.Bool("use-udecimal", false, "By default, FIX uses the shopspring/decimal library for fixed-point decimal numbers.  Set to 'true' to instead use the quagmt/udecimal library.")
+	pkgRoot     = flag.String("pkg-root", "github.com/quickfixgo", "Set a string here to provide a custom import path for generated packages.")
+	tabWidth    = 8
+	printerMode = printer.UseSpaces | printer.TabIndent
+)
+
+// ParseError indicates generated go source is invalid
+type ParseError struct {
+	path string
+	err  error
+}
+
+func (e ParseError) Error() string {
+	return fmt.Sprintf("Error parsing %v: %v", e.path, e.err)
+}
+
+// ErrorHandler is a convenience struct for interpretting generation Errors
+type ErrorHandler struct {
+	ReturnCode int
+}
+
+// Handle interprets the generation error. Proceeds with setting returnCode, or panics depending on error type
+func (h *ErrorHandler) Handle(err error) {
+	switch err := err.(type) {
+	case nil:
+	//do nothing
+	case ParseError:
+		fmt.Println(err)
+		h.ReturnCode = 1
+	default:
+		panic(err)
+	}
+}
+
+func write(filePath string, fset *token.FileSet, f *ast.File) error {
+	if parentdir := path.Dir(filePath); parentdir != "." {
+		if err := os.MkdirAll(parentdir, os.ModePerm); err != nil {
+			return err
+		}
+	}
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		return err
+	}
+
+	ast.SortImports(fset, f)
+	err = (&printer.Config{Mode: printerMode, Tabwidth: tabWidth}).Fprint(file, fset, f)
+	_ = file.Close()
+	return err
+}
+
+// WriteFile parses the generated code in fileOut and writes the code out to filePath.
+// Function performs some import clean up and gofmts the code before writing
+// Returns ParseError if the generated source is invalid but is written to filePath
+func WriteFile(filePath, fileOut string) error {
+	fset := token.NewFileSet()
+	f, pErr := parser.ParseFile(fset, "", fileOut, parser.ParseComments)
+	if f == nil {
+		return pErr
+	}
+
+	//write out the file regardless of parseFile errors
+	if err := write(filePath, fset, f); err != nil {
+		return err
+	}
+
+	if pErr != nil {
+		return ParseError{path: filePath, err: pErr}
+	}
+
+	return nil
+}