Add backticks support for string blocks (#65)

Fixes gobuffalo/pop#168

functions_test.go

@@ -3,6 +3,7 @@ package plush
 import (
 	"errors"
 	"fmt"
+	"html/template"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -127,3 +128,52 @@ func Test_Render_Function_Optional_Map(t *testing.T) {
 	r.NoError(err)
 	r.Equal("foo|A", s)
 }
+
+func Test_Render_Function_With_Backticks_And_Quotes(t *testing.T) {
+	// From https://github.com/gobuffalo/pop/issues/168
+	r := require.New(t)
+	input := "<%= raw(`" + `CREATE MATERIALIZED VIEW view_papers AS
+	SELECT papers.created_at,
+	   papers.updated_at,
+	   papers.id,
+	   papers.name,
+	   (   setweight(to_tsvector(papers.name::text), 'A'::"char") || 
+		   setweight(to_tsvector(papers.author_name), 'B'::"char")
+	   ) || setweight(to_tsvector(papers.description), 'C'::"char")
+	   AS paper_vector
+	  FROM
+	  ( SELECT papers.id, string_agg(categories.code, ',') as categories
+	   FROM papers
+	   LEFT JOIN paper_categories ON paper_categories.paper_id=papers.id LEFT JOIN (select * from categories order by weight asc) categories ON categories.id=paper_categories.category_id
+	   GROUP BY papers.id
+	  ) a
+	  LEFT JOIN papers on a.id=papers.id
+	 WHERE (papers.doc_status = ANY (ARRAY[1, 3])) AND papers.status = 1
+   WITH DATA` + "`) %>"
+
+	output := `CREATE MATERIALIZED VIEW view_papers AS
+	SELECT papers.created_at,
+	   papers.updated_at,
+	   papers.id,
+	   papers.name,
+	   (   setweight(to_tsvector(papers.name::text), 'A'::"char") || 
+		   setweight(to_tsvector(papers.author_name), 'B'::"char")
+	   ) || setweight(to_tsvector(papers.description), 'C'::"char")
+	   AS paper_vector
+	  FROM
+	  ( SELECT papers.id, string_agg(categories.code, ',') as categories
+	   FROM papers
+	   LEFT JOIN paper_categories ON paper_categories.paper_id=papers.id LEFT JOIN (select * from categories order by weight asc) categories ON categories.id=paper_categories.category_id
+	   GROUP BY papers.id
+	  ) a
+	  LEFT JOIN papers on a.id=papers.id
+	 WHERE (papers.doc_status = ANY (ARRAY[1, 3])) AND papers.status = 1
+   WITH DATA`
+	s, err := Render(input, NewContextWith(map[string]interface{}{
+		"raw": func(arg string) template.HTML {
+			return template.HTML(arg)
+		},
+	}))
+	r.NoError(err)
+	r.Equal(output, s)
+}

lexer/lexer.go

@@ -170,6 +170,9 @@ func (l *Lexer) nextInsideToken() token.Token {
 	case '"':
 		tok.Type = token.STRING
 		tok.Literal = l.readString()
+	case '`':
+		tok.Type = token.B_STRING
+		tok.Literal = l.readBString()
 	case '[':
 		tok = l.newToken(token.LBRACKET)
 	case ']':
@@ -275,6 +278,18 @@ func (l *Lexer) readString() string {
 	return strings.Replace(s, "\\\"", "\"", -1)
 }
 
+func (l *Lexer) readBString() string {
+	position := l.position + 1
+	for l.ch != 0 {
+		l.readChar()
+		if l.ch == '`' {
+			break
+		}
+	}
+	s := l.input[position:l.position]
+	return s
+}
+
 func (l *Lexer) readHTML() string {
 	position := l.position
 

parser/parser.go

@@ -36,6 +36,7 @@ func newParser(l *lexer.Lexer) *parser {
 	p.registerPrefix(token.INT, p.parseIntegerLiteral)
 	p.registerPrefix(token.FLOAT, p.parseFloatLiteral)
 	p.registerPrefix(token.STRING, p.parseStringLiteral)
+	p.registerPrefix(token.B_STRING, p.parseStringLiteral)
 	p.registerPrefix(token.BANG, p.parsePrefixExpression)
 	p.registerPrefix(token.MINUS, p.parsePrefixExpression)
 	p.registerPrefix(token.TRUE, p.parseBoolean)

parser/parser_test.go

@@ -650,6 +650,19 @@ func Test_StringLiteralExpression(t *testing.T) {
 	r.Equal("hello world", literal.Value)
 }
 
+func Test_StringBlockExpression(t *testing.T) {
+	r := require.New(t)
+	input := "<% `hello world`; %>"
+
+	program, err := Parse(input)
+	r.NoError(err)
+
+	stmt := program.Statements[0].(*ast.ExpressionStatement)
+	literal := stmt.Expression.(*ast.StringLiteral)
+
+	r.Equal("hello world", literal.Value)
+}
+
 func Test_EmptyArrayLiterals(t *testing.T) {
 	r := require.New(t)
 	input := "<% [] %>"

token/const.go

@@ -5,12 +5,13 @@ const (
 	EOF     = "EOF"
 
 	// Identifiers + literals
-	IDENT  = "IDENT"  // add, foobar, x, y, ...
-	INT    = "INT"    // 1343456
-	FLOAT  = "FLOAT"  // 12.34
-	STRING = "STRING" // "foobar"
-	HTML   = "HTML"   // <p>adf</p>
-	DOT    = "DOT"    // .23
+	IDENT    = "IDENT"    // add, foobar, x, y, ...
+	INT      = "INT"      // 1343456
+	FLOAT    = "FLOAT"    // 12.34
+	STRING   = "STRING"   // "foobar"
+	B_STRING = "B_STRING" // `foobar`
+	HTML     = "HTML"     // <p>adf</p>
+	DOT      = "DOT"      // .23
 
 	// Operators
 	ASSIGN   = "="