sqlite: Add experimental parser for SQLite

Author: kyleconroy

internal/sqlite/parse.go

@@ -0,0 +1,108 @@
+package sqlite
+
+import (
+	"errors"
+	"io"
+	"io/ioutil"
+
+	"github.com/antlr/antlr4/runtime/Go/antlr"
+
+	"github.com/kyleconroy/sqlc/internal/sql/ast"
+	"github.com/kyleconroy/sqlc/internal/sqlite/parser"
+)
+
+type listener struct {
+	*parser.BaseSQLiteListener
+
+	stmt *ast.RawStmt
+
+	stmts []ast.Statement
+}
+
+func (l *listener) EnterSql_stmt(c *parser.Sql_stmtContext) {
+	l.stmt = nil
+}
+
+func (l *listener) ExitSql_stmt(c *parser.Sql_stmtContext) {
+	if l.stmt != nil {
+		l.stmts = append(l.stmts, ast.Statement{
+			Raw: l.stmt,
+		})
+		return
+	}
+}
+
+func (l *listener) EnterCreate_table_stmt(c *parser.Create_table_stmtContext) {
+	name := ast.TableName{
+		Name: c.Table_name().GetText(),
+	}
+
+	if c.Database_name() != nil {
+		name.Schema = c.Database_name().GetText()
+	}
+
+	stmt := &ast.CreateTableStmt{
+		Name:        &name,
+		IfNotExists: c.K_EXISTS() != nil,
+	}
+
+	for _, idef := range c.AllColumn_def() {
+		if def, ok := idef.(*parser.Column_defContext); ok {
+			stmt.Cols = append(stmt.Cols, &ast.ColumnDef{
+				Colname: def.Column_name().GetText(),
+				TypeName: &ast.TypeName{
+					Name: def.Type_name().GetText(),
+				},
+			})
+		}
+	}
+
+	l.stmt = &ast.RawStmt{Stmt: stmt}
+}
+
+type errorListener struct {
+	*antlr.DefaultErrorListener
+
+	err string
+}
+
+func (el *errorListener) SyntaxError(recognizer antlr.Recognizer, offendingSymbol interface{}, line, column int, msg string, e antlr.RecognitionException) {
+	el.err = msg
+}
+
+// func (el *errorListener) ReportAmbiguity(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex int, exact bool, ambigAlts *antlr.BitSet, configs antlr.ATNConfigSet) {
+// }
+//
+// func (el *errorListener) ReportAttemptingFullContext(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex int, conflictingAlts *antlr.BitSet, configs antlr.ATNConfigSet) {
+// }
+//
+// func (el *errorListener) ReportContextSensitivity(recognizer antlr.Parser, dfa *antlr.DFA, startIndex, stopIndex, prediction int, configs antlr.ATNConfigSet) {
+// }
+
+func NewParser() *Parser {
+	return &Parser{}
+}
+
+type Parser struct {
+}
+
+func (p *Parser) Parse(r io.Reader) ([]ast.Statement, error) {
+	blob, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	input := antlr.NewInputStream(string(blob))
+	lexer := parser.NewSQLiteLexer(input)
+	stream := antlr.NewCommonTokenStream(lexer, 0)
+	pp := parser.NewSQLiteParser(stream)
+	l := &listener{}
+	el := &errorListener{}
+	pp.AddErrorListener(el)
+	tree := pp.Parse()
+	if el.err != "" {
+		return nil, errors.New(el.err)
+	}
+	// p.BuildParseTrees = true
+	antlr.ParseTreeWalkerDefault.Walk(l, tree)
+	return l.stmts, nil
+}

internal/sqlite/parser/Makefile

@@ -0,0 +1,2 @@
+sqlite_parser.go: SQLite.g4
+	antlr -Dlanguage=Go -visitor SQLite.g4