eliminate additional newline at end of substitutions

Author: mandelsoft

README.md

@@ -1,6 +1,7 @@
-<!-- DO NOT MODIDY                   -->
+<!-- DO NOT MODIFY                   -->
 <!-- this file is generated by mdref -->
 <!-- from src/README.md              -->
+
 # Markdown Reference Generator
 
 This markdown reference generator uses
@@ -28,7 +29,6 @@ Flags:
   --skip-execute omit the evaluation of the execute statement (for test purposes, only)
   --skip-source  omit source reference in generation comment
   --list         print reference index and usage list
-
 ```
 
 If called without a target folder a consistency check is

cmds.go

@@ -14,6 +14,7 @@ import (
 
 type Command interface {
 	Position() string
+	EOL() bool
 	GetSubstitution(path string, opts Options) ([]byte, error)
 }
 
@@ -23,6 +24,7 @@ type Commands map[string]Command
 
 type Include struct {
 	_Position
+	nl        bool
 	file      string
 	filter    *filter
 	extractor extractor
@@ -36,6 +38,10 @@ type filter struct {
 	filter *regexp.Regexp
 }
 
+func (i *Include) EOL() bool {
+	return i.nl
+}
+
 func (i *Include) getData(p string) ([]byte, error) {
 	if !filepath.IsAbs(i.file) {
 		p = filepath.Join(filepath.Dir(p), i.file)
@@ -106,7 +112,7 @@ var includeExpPat = regexp.MustCompile("^{([^}]+)}{([a-zA-Z][a-zA-Z0-9 -]*)}(?:{
 // --- end include args ---
 // --- end example ---
 
-func NewInclude(pos Position, args []byte) (Command, error) {
+func NewInclude(pos Position, args []byte, nl bool) (Command, error) {
 	var err error
 
 	matches := includeExpNum.FindSubmatch(args)
@@ -137,7 +143,7 @@ func NewInclude(pos Position, args []byte) (Command, error) {
 				return nil, fmt.Errorf("invalid filter expression: %w", err)
 			}
 		}
-		return &Include{pos, string(matches[1]), &filter{fexp}, &NumExtractor{int(start), int(end)}}, nil
+		return &Include{pos, nl, string(matches[1]), &filter{fexp}, &NumExtractor{int(start), int(end)}}, nil
 	}
 
 	matches = includeExpPat.FindSubmatch(args)
@@ -149,7 +155,7 @@ func NewInclude(pos Position, args []byte) (Command, error) {
 				return nil, fmt.Errorf("invalid filter expression: %w", err)
 			}
 		}
-		return &Include{pos, string(matches[1]), &filter{fexp}, &PatternExtractor{string(matches[2])}}, nil
+		return &Include{pos, nl, string(matches[1]), &filter{fexp}, &PatternExtractor{string(matches[2])}}, nil
 	}
 
 	return nil, fmt.Errorf("invalid include arguments %q", string(args))
@@ -220,6 +226,7 @@ func (i *PatternExtractor) match(data []byte, key string) (int, int, error) {
 
 type Execute struct {
 	_Position
+	nl        bool
 	cmd       []string
 	filter    *filter
 	extractor extractor
@@ -228,6 +235,10 @@ type Execute struct {
 
 var _ Command = (*Execute)(nil)
 
+func (e *Execute) EOL() bool {
+	return e.nl
+}
+
 func (e *Execute) GetSubstitution(path string, opts Options) ([]byte, error) {
 
 	if opts.SkipExecute {
@@ -268,7 +279,7 @@ var nextarg = regexp.MustCompile("^{([^}]+)}(.*)$")
 var extractExpNum = regexp.MustCompile("^([0-9]+)?(?:(:)([0-9]+)?)?$")
 var extractExpPat = regexp.MustCompile("^([a-zA-Z -]+)$")
 
-func NewExecute(pos Position, args []byte) (Command, error) {
+func NewExecute(pos Position, args []byte, nl bool) (Command, error) {
 	var cmd []string
 
 	for {
@@ -339,5 +350,5 @@ func NewExecute(pos Position, args []byte) (Command, error) {
 			return nil, fmt.Errorf("invalid filter expression: %w", err)
 		}
 	}
-	return &Execute{pos, cmd, &filter{fexp}, ext, nil}, nil
+	return &Execute{pos, nl, cmd, &filter{fexp}, ext, nil}, nil
 }

doc/chapters/commands.md

@@ -1,6 +1,7 @@
-<!-- DO NOT MODIDY                           -->
+<!-- DO NOT MODIFY                           -->
 <!-- this file is generated by mdref         -->
 <!-- from ../../src/doc/chapters/commands.md -->
+
 ## Commands
 
 Commands provide additional functionality to Markdown files.
@@ -78,7 +79,6 @@ the content of the first matching group of the all matches is
 concatenated. If the expression uses the multi-line mode, the matches
 are suffixed with a newline.
 
-
 The previous paragraph is taken from the source file
 ```go
 // --- begin filter ---
@@ -123,7 +123,6 @@ some demo text
 // --- end text ---
 this is line 5 of the demo output
 and some other text.
-
 ```
 
 It can be completely substituted (as shown above) with the command

doc/chapters/references.md

@@ -1,6 +1,7 @@
-<!-- DO NOT MODIDY                             -->
+<!-- DO NOT MODIFY                             -->
 <!-- this file is generated by mdref           -->
 <!-- from ../../src/doc/chapters/references.md -->
+
 ## References
 
 Any reference in a Markdown document may

doc/chapters/terms.md

@@ -1,6 +1,7 @@
-<!-- DO NOT MODIDY                        -->
+<!-- DO NOT MODIFY                        -->
 <!-- this file is generated by mdref      -->
 <!-- from ../../src/doc/chapters/terms.md -->
+
 ## Terms
 
 Instead of using a reference as target for a markdown

generate.go

@@ -43,6 +43,7 @@ func generate(files []*File, resolution Resolution, source, target string, opts
 			if err == nil && !opts.SkipSource {
 				w.Write(comment(fmt.Sprintf("from %s", rel), l))
 			}
+			w.Write([]byte("\n"))
 		}
 		if !f.HasSubst() {
 			_, err := io.Copy(w, r)
@@ -96,6 +97,9 @@ func generate(files []*File, resolution Resolution, source, target string, opts
 				if err != nil {
 					return fmt.Errorf("%s: %s: %s; %w", f.relpath, c.Position(), k, err)
 				}
+				if c.EOL() && sub[len(sub)-1] == '\n' {
+					sub = sub[:len(sub)-1]
+				}
 				data = exp.ReplaceAll(data, sub)
 			}
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/mandelsoft/mdref
 
-go 1.21
+go 1.23.2
 
 require (
 	github.com/Masterminds/semver/v3 v3.2.1

scan.go

@@ -186,13 +186,17 @@ func scanRefs(src string, opts Options) (Refs, Refs, Refs, Commands, error) {
 	matches, indices = info.scanFor(cmdExp)
 	for i, m := range matches {
 		var cmd Command
+		nl := false
 		pos := info.Position(indices[i][0])
 		key := string(m[1])
+		if len(info.data) > indices[i][0]+len(m[0]) {
+			nl = info.data[indices[i][0]+len(m[0])] == '\n'
+		}
 		switch key {
 		case "include":
-			cmd, err = NewInclude(pos, m[2])
+			cmd, err = NewInclude(pos, m[2], nl)
 		case "execute":
-			cmd, err = NewExecute(pos, m[2])
+			cmd, err = NewExecute(pos, m[2], nl)
 		default:
 			err = fmt.Errorf("invalid command %q", key)
 		}

test/README.md

@@ -1,6 +1,7 @@
 <!-- DO NOT MODIFY                   -->
 <!-- this file is generated by mdref -->
 <!-- from ../src/README.md           -->
+
 # Markdown Reference Generator
 
 This markdown reference generator uses
@@ -28,7 +29,6 @@ Flags:
   --skip-execute omit the evaluation of the execute statement (for test purposes, only)
   --skip-source  omit source reference in generation comment
   --list         print reference index and usage list
-
 ```
 
 If called without a target folder a consistency check is

test/doc/chapters/commands.md

@@ -1,6 +1,7 @@
 <!-- DO NOT MODIFY                              -->
 <!-- this file is generated by mdref            -->
 <!-- from ../../../src/doc/chapters/commands.md -->
+
 ## Commands
 
 Commands provide additional functionality to Markdown files.
@@ -78,7 +79,6 @@ the content of the first matching group of the all matches is
 concatenated. If the expression uses the multi-line mode, the matches
 are suffixed with a newline.
 
-
 The previous paragraph is taken from the source file
 ```go
 // --- begin filter ---
@@ -123,7 +123,6 @@ some demo text
 // --- end text ---
 this is line 5 of the demo output
 and some other text.
-
 ```
 
 It can be completely substituted (as shown above) with the command

test/doc/chapters/references.md

@@ -1,6 +1,7 @@
 <!-- DO NOT MODIFY                                -->
 <!-- this file is generated by mdref              -->
 <!-- from ../../../src/doc/chapters/references.md -->
+
 ## References
 
 Any reference in a Markdown document may

test/doc/chapters/terms.md

@@ -1,6 +1,7 @@
 <!-- DO NOT MODIFY                           -->
 <!-- this file is generated by mdref         -->
 <!-- from ../../../src/doc/chapters/terms.md -->
+
 ## Terms
 
 Instead of using a reference as target for a markdown