init

.gitignore

@@ -0,0 +1 @@
+pp

build.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+#
+go build ./cmd/pp

errors.go

@@ -0,0 +1,15 @@
+package pp
+
+import (
+	//"errors"
+	"fmt"
+)
+
+type UnexpectedError struct {
+	What string
+	Line int
+}
+func (err UnexpectedError) Error() string {
+	return fmt.Sprintf("%d: unexpected %s", err.Line, err.What)
+}
+

go.mod

@@ -0,0 +1,8 @@
+module vultras.su/util/pp
+
+go 1.21.7
+
+require (
+	github.com/d5/tengo/v2 v2.16.1 // indirect
+	vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0 // indirect
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/d5/tengo/v2 v2.16.1 h1:/N6dqiGu9toqANInZEOQMM8I06icdZnmb+81DG/lZdw=
+github.com/d5/tengo/v2 v2.16.1/go.mod h1:XRGjEs5I9jYIKTxly6HCF8oiiilk5E/RYXOZ5b0DZC8=
+vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0 h1:acA77oEg7hDuUchyBvw7scG9gayVLFAC9/CGuqyfLSA=
+vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0/go.mod h1:rYu/sFWE3vUkDSSJCZt+K1aVaso0MYcZ+tmxQd4whdQ=

main.go

@@ -0,0 +1,109 @@
+package pp
+
+import (
+	"github.com/d5/tengo/v2"
+	"github.com/d5/tengo/v2/stdlib"
+	"context"
+	"strings"
+	"fmt"
+)
+
+type Preprocessor struct {
+	// The string will be inserted in the
+	// beginning of processed files.
+	head string
+
+	tags [2]string
+	modules *tengo.ModuleMap
+}
+
+// Evaluate the expression and return the value
+// it would print.
+func (pp *Preprocessor) Eval(data string) (string, error) {
+	const retHead = `
+		printf := func(format, ...vals) {
+			__ret__ += __Sprintf(format, vals...)
+		}
+	`
+	script := tengo.NewScript([]byte(retHead + pp.head + "\n" + data))
+	err := script.Add("__Sprintf", &tengo.UserFunction{
+			Value: func(args ...tengo.Object) (tengo.Object, error){
+				if len(args) < 1 {
+					return nil, tengo.ErrWrongNumArguments
+				}
+				format, ok := tengo.ToString(args[0])
+				if !ok {
+					return nil, tengo.ErrInvalidArgumentType{
+						Expected: "string",
+					}
+				}
+				gargs := make([]any, len(args) - 1)
+				for i := range gargs {
+					gargs[i] = tengo.ToInterface(args[i+1])
+					//fmt.Printf("shit: %q\n", gargs[i])
+				}
+				str := fmt.Sprintf(format, gargs...)
+				return tengo.FromInterface(str)
+			},
+		},
+	)
+	if err != nil {
+		return "", err
+	}
+	err = script.Add("__ret__", "")
+	if err != nil{ 
+		return "", err
+	}
+	compiled, err := script.RunContext(context.Background())
+	if err != nil {
+		return "", err
+	}
+
+	return compiled.Get("__ret__").String(), nil
+}
+
+// Get the new preprocessor with default options.
+func NewPp() *Preprocessor {
+	pp := &Preprocessor{
+		tags: [2]string{
+			"<?tengo",
+			"?>",
+		},
+		modules: stdlib.GetModuleMap(stdlib.AllModuleNames()...)
+	}
+	return pp
+}
+
+func (pp *Preprocessor) Process(data string) (string, error) {
+	var b strings.Builder
+	last := 0
+	for {
+		idxStart := strings.Index(data[last:], pp.tags[0])
+		idxEnd := strings.Index(data[last:], pp.tags[1])
+		//fmt.Printf("cock %d %d %d\n", last, idxStart, idxEnd)
+		if idxStart < 0 {
+			if idxEnd >= 0 {
+				return "", UnexpectedError{
+					What: "end tag",
+				}
+			}
+			fmt.Fprint(&b, data[last:])
+			break
+		} else if idxEnd < 0 {
+			return "", UnexpectedError{
+				What: "start tag",
+			}
+		}
+		fmt.Fprint(&b, data[last:idxStart])
+		code := data[idxStart+len(pp.tags[0]):idxEnd]
+		str, err := pp.Eval(code)
+		if err != nil {
+			return "", err
+		}
+		fmt.Fprint(&b, str)
+		data = data[idxEnd + len(pp.tags[1])+1:]
+	}
+
+	return b.String(), nil
+}
+

tests/index.md.pp

@@ -0,0 +1,11 @@
+# The index testing
+	1 + 1 = <?tengo
+		printf("%d", 1+1)
+		printf("\ncock")
+	?>
+## The shit after
+
+checking <?tengo
+	printf("second shit")
+?>
+

tool.go

@@ -0,0 +1,28 @@
+package pp
+
+import (
+	"vultras.su/core/cli/mtool"
+	"fmt"
+	"os"
+	"log"
+	"path/filepath"
+)
+
+var Tool = mtool.T("pp").Func(func(flags *mtool.Flags){
+	pp := NewPp()
+	filePaths := flags.Parse()
+	for _, filePath := range filePaths {
+		pth := filepath.FromSlash(filePath)
+		bts, err := os.ReadFile(pth)
+		if err != nil {
+			log.Println("read error:", err)
+			continue
+		}
+		str, err := pp.Process(string(bts))
+		if err != nil {
+			log.Println("pp error:", err)
+			continue
+		}
+		fmt.Print(str)
+	}
+})