caddyfile: Support for raw token values; improve `map`, `expression` (#4643)

* caddyfile: Support for raw token values, improve `map`, `expression`

* Applied code review comments

* Rename RawVal to ValRaw

Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>

2 files changed, 70 insertions, 5 deletions

diff --git a/caddyconfig/caddyfile/dispenser.go b/caddyconfig/caddyfile/dispenser.go
index 23f6ead..fbe71ad 100755
--- a/caddyconfig/caddyfile/dispenser.go
+++ b/caddyconfig/caddyfile/dispenser.go
@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"strconv"
 	"strings"
 )
 
@@ -201,6 +202,43 @@ func (d *Dispenser) Val() string {
 	return d.tokens[d.cursor].Text
 }
 
+// ValRaw gets the raw text of the current token (including quotes).
+// If there is no token loaded, it returns empty string.
+func (d *Dispenser) ValRaw() string {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return ""
+	}
+	quote := d.tokens[d.cursor].wasQuoted
+	if quote > 0 {
+		return string(quote) + d.tokens[d.cursor].Text + string(quote) // string literal
+	}
+	return d.tokens[d.cursor].Text
+}
+
+// ScalarVal gets value of the current token, converted to the closest
+// scalar type. If there is no token loaded, it returns nil.
+func (d *Dispenser) ScalarVal() interface{} {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return nil
+	}
+	quote := d.tokens[d.cursor].wasQuoted
+	text := d.tokens[d.cursor].Text
+
+	if quote > 0 {
+		return text // string literal
+	}
+	if num, err := strconv.Atoi(text); err == nil {
+		return num
+	}
+	if num, err := strconv.ParseFloat(text, 64); err == nil {
+		return num
+	}
+	if bool, err := strconv.ParseBool(text); err == nil {
+		return bool
+	}
+	return text
+}
+
 // Line gets the line number of the current token.
 // If there is no token loaded, it returns 0.
 func (d *Dispenser) Line() int {
@@ -249,6 +287,19 @@ func (d *Dispenser) AllArgs(targets ...*string) bool {
 	return true
 }
 
+// CountRemainingArgs counts the amount of remaining arguments
+// (tokens on the same line) without consuming the tokens.
+func (d *Dispenser) CountRemainingArgs() int {
+	count := 0
+	for d.NextArg() {
+		count++
+	}
+	for i := 0; i < count; i++ {
+		d.Prev()
+	}
+	return count
+}
+
 // RemainingArgs loads any more arguments (tokens on the same line)
 // into a slice and returns them. Open curly brace tokens also indicate
 // the end of arguments, and the curly brace is not included in
@@ -261,6 +312,18 @@ func (d *Dispenser) RemainingArgs() []string {
 	return args
 }
 
+// RemainingArgsRaw loads any more arguments (tokens on the same line,
+// retaining quotes) into a slice and returns them. Open curly brace
+// tokens also indicate the end of arguments, and the curly brace is
+// not included in the return value nor is it loaded.
+func (d *Dispenser) RemainingArgsRaw() []string {
+	var args []string
+	for d.NextArg() {
+		args = append(args, d.ValRaw())
+	}
+	return args
+}
+
 // NewFromNextSegment returns a new dispenser with a copy of
 // the tokens from the current token until the end of the
 // "directive" whether that be to the end of the line or
diff --git a/caddyconfig/caddyfile/lexer.go b/caddyconfig/caddyfile/lexer.go
index 968277f..4a23524 100755
--- a/caddyconfig/caddyfile/lexer.go
+++ b/caddyconfig/caddyfile/lexer.go
@@ -38,6 +38,7 @@ type (
 		File        string
 		Line        int
 		Text        string
+		wasQuoted   rune // enclosing quote character, if any
 		inSnippet   bool
 		snippetName string
 	}
@@ -78,8 +79,9 @@ func (l *lexer) next() bool {
 	var val []rune
 	var comment, quoted, btQuoted, escaped bool
 
-	makeToken := func() bool {
+	makeToken := func(quoted rune) bool {
 		l.token.Text = string(val)
+		l.token.wasQuoted = quoted
 		return true
 	}
 
@@ -87,7 +89,7 @@ func (l *lexer) next() bool {
 		ch, _, err := l.reader.ReadRune()
 		if err != nil {
 			if len(val) > 0 {
-				return makeToken()
+				return makeToken(0)
 			}
 			if err == io.EOF {
 				return false
@@ -110,10 +112,10 @@ func (l *lexer) next() bool {
 				escaped = false
 			} else {
 				if quoted && ch == '"' {
-					return makeToken()
+					return makeToken('"')
 				}
 				if btQuoted && ch == '`' {
-					return makeToken()
+					return makeToken('`')
 				}
 			}
 			if ch == '\n' {
@@ -139,7 +141,7 @@ func (l *lexer) next() bool {
 				comment = false
 			}
 			if len(val) > 0 {
-				return makeToken()
+				return makeToken(0)
 			}
 			continue
 		}