github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/parsers/dialect/postgresql/postgresql_lexer.go (about)

     1  // Copyright 2021 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package postgresql
    16  
    17  import (
    18  	"context"
    19  	"strconv"
    20  
    21  	"github.com/matrixorigin/matrixone/pkg/common/moerr"
    22  	"github.com/matrixorigin/matrixone/pkg/sql/parsers/dialect"
    23  	"github.com/matrixorigin/matrixone/pkg/sql/parsers/tree"
    24  )
    25  
    26  func Parse(ctx context.Context, sql string) ([]tree.Statement, error) {
    27  	lexer := NewLexer(dialect.POSTGRESQL, sql)
    28  	if yyParse(lexer) != 0 {
    29  		return nil, lexer.scanner.LastError
    30  	}
    31  	return lexer.stmts, nil
    32  }
    33  
    34  func ParseOne(ctx context.Context, sql string) (tree.Statement, error) {
    35  	lexer := NewLexer(dialect.POSTGRESQL, sql)
    36  	if yyParse(lexer) != 0 {
    37  		return nil, lexer.scanner.LastError
    38  	}
    39  	if len(lexer.stmts) != 1 {
    40  		return nil, moerr.NewInternalError(ctx, "syntax Error, or too many sql to parse")
    41  	}
    42  	return lexer.stmts[0], nil
    43  }
    44  
    45  type Lexer struct {
    46  	scanner *Scanner
    47  	stmts   []tree.Statement
    48  }
    49  
    50  func NewLexer(dialectType dialect.DialectType, sql string) *Lexer {
    51  	return &Lexer{
    52  		scanner: NewScanner(dialectType, sql),
    53  	}
    54  }
    55  
    56  func (l *Lexer) Lex(lval *yySymType) int {
    57  	typ, str := l.scanner.Scan()
    58  	l.scanner.LastToken = str
    59  
    60  	switch typ {
    61  	case INTEGRAL:
    62  		return l.toInt(lval, str)
    63  	case FLOAT:
    64  		return l.toFloat(lval, str)
    65  	case HEX:
    66  		return l.toHex(lval, str)
    67  	case HEXNUM:
    68  		return l.toHexNum(lval, str)
    69  	case BIT_LITERAL:
    70  		return l.toBit(lval, str)
    71  	}
    72  
    73  	lval.str = str
    74  	return typ
    75  }
    76  
    77  func (l *Lexer) Error(err string) {
    78  	l.scanner.LastError = PositionedErr{Err: err, Pos: l.scanner.Pos + 1, Near: l.scanner.LastToken}
    79  }
    80  
    81  func (l *Lexer) AppendStmt(stmt tree.Statement) {
    82  	l.stmts = append(l.stmts, stmt)
    83  }
    84  
    85  func (l *Lexer) toInt(lval *yySymType, str string) int {
    86  	ival, err := strconv.ParseInt(str, 10, 64)
    87  	if err != nil {
    88  		l.scanner.LastError = err
    89  	}
    90  	lval.item = ival
    91  	return INTEGRAL
    92  }
    93  
    94  func (l *Lexer) toFloat(lval *yySymType, str string) int {
    95  	fval, err := strconv.ParseFloat(str, 64)
    96  	if err != nil {
    97  		l.scanner.LastError = err
    98  	}
    99  	lval.item = fval
   100  	return FLOAT
   101  }
   102  
   103  func (l *Lexer) toHex(lval *yySymType, str string) int {
   104  	return HEX
   105  }
   106  
   107  func (l *Lexer) toHexNum(lval *yySymType, str string) int {
   108  	return HEXNUM
   109  }
   110  
   111  func (l *Lexer) toBit(lval *yySymType, str string) int {
   112  	return BIT_LITERAL
   113  }