modernc.org/knuth@v0.0.4/mft/etc.go (about)

     1  // Copyright 2023 The Knuth Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package mft // modernc.org/knuth/mft
     6  
     7  import (
     8  	"fmt"
     9  	"os"
    10  	"path/filepath"
    11  	"runtime"
    12  	"strings"
    13  )
    14  
    15  // origin returns caller's short position, skipping skip frames.
    16  func origin(skip int) string {
    17  	pc, fn, fl, _ := runtime.Caller(skip)
    18  	f := runtime.FuncForPC(pc)
    19  	var fns string
    20  	if f != nil {
    21  		fns = f.Name()
    22  		if x := strings.LastIndex(fns, "."); x > 0 {
    23  			fns = fns[x+1:]
    24  		}
    25  		if strings.HasPrefix(fns, "func") {
    26  			num := true
    27  			for _, c := range fns[len("func"):] {
    28  				if c < '0' || c > '9' {
    29  					num = false
    30  					break
    31  				}
    32  			}
    33  			if num {
    34  				return origin(skip + 2)
    35  			}
    36  		}
    37  	}
    38  	return fmt.Sprintf("%s:%d:%s", filepath.Base(fn), fl, fns)
    39  }
    40  
    41  // todo prints and returns caller's position and an optional message tagged with TODO. Output goes to stderr.
    42  //lint:ignore U1000 whatever
    43  func todo(s string, args ...interface{}) string {
    44  	switch {
    45  	case s == "":
    46  		s = fmt.Sprintf(strings.Repeat("%v ", len(args)), args...)
    47  	default:
    48  		s = fmt.Sprintf(s, args...)
    49  	}
    50  	r := fmt.Sprintf("%s\n\tTODO %s", origin(2), s)
    51  	// fmt.Fprintf(os.Stderr, "%s\n", r)
    52  	// os.Stdout.Sync()
    53  	return r
    54  }
    55  
    56  // trc prints and returns caller's position and an optional message tagged with TRC. Output goes to stderr.
    57  //lint:ignore U1000 whatever
    58  func trc(s string, args ...interface{}) string {
    59  	switch {
    60  	case s == "":
    61  		s = fmt.Sprintf(strings.Repeat("%v ", len(args)), args...)
    62  	default:
    63  		s = fmt.Sprintf(s, args...)
    64  	}
    65  	r := fmt.Sprintf("%s: TRC %s", origin(2), s)
    66  	fmt.Fprintf(os.Stderr, "%s\n", r)
    67  	os.Stderr.Sync()
    68  	return r
    69  }