Hello world

pkg/parser/parser.go

@@ -0,0 +1,31 @@
+//go:generate antlr4 -Xexact-output-dir -o fql -package fql -visitor -Dlanguage=Go antlr/FqlLexer.g4 antlr/FqlParser.g4
+package parser
+
+import (
+	"github.com/MontFerret/ferret/pkg/parser/fql"
+	"github.com/antlr/antlr4/runtime/Go/antlr"
+)
+
+type Parser struct {
+	tree *fql.FqlParser
+}
+
+func New(query string) *Parser {
+	input := antlr.NewInputStream(query)
+	lexer := fql.NewFqlLexer(input)
+	stream := antlr.NewCommonTokenStream(lexer, antlr.TokenDefaultChannel)
+
+	p := fql.NewFqlParser(stream)
+	p.BuildParseTrees = true
+	p.AddErrorListener(antlr.NewDiagnosticErrorListener(true))
+
+	return &Parser{tree: p}
+}
+
+func (p *Parser) AddErrorListener(listener antlr.ErrorListener) {
+	p.tree.AddErrorListener(listener)
+}
+
+func (p *Parser) Visit(visitor fql.FqlParserVisitor) interface{} {
+	return visitor.VisitProgram(p.tree.Program().(*fql.ProgramContext))
+}