aa7e4ac561
The SQL parser now supports model expressions for defining ranges using the |table:0,0.5..100| notation syntax.
899 lines
17 KiB
Go
899 lines
17 KiB
Go
// Copyright © 2016 Abcum Ltd
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package sql
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import (
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"fmt"
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"regexp"
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"time"
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"golang.org/x/crypto/bcrypt"
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"github.com/abcum/surreal/util/rand"
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)
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func (p *parser) parseWhat() (mul []Expr, err error) {
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for {
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tok, lit, err := p.shouldBe(IDENT, THING, PARAM, MODEL)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"table, or thing"}}
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}
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if p.is(tok, IDENT) {
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one, _ := p.declare(TABLE, lit)
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mul = append(mul, one)
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}
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if p.is(tok, THING) {
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one, _ := p.declare(THING, lit)
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mul = append(mul, one)
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}
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if p.is(tok, PARAM) {
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one, _ := p.declare(PARAM, lit)
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mul = append(mul, one)
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}
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if p.is(tok, MODEL) {
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one, _ := p.declare(MODEL, lit)
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mul = append(mul, one)
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}
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// Check to see if the next token is a comma
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// and if not, then break out of the loop,
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// otherwise repeat until we find no comma.
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if _, _, exi := p.mightBe(COMMA); !exi {
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break
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}
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}
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return
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}
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func (p *parser) parseIdent() (*Ident, error) {
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_, lit, err := p.shouldBe(IDENT)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"name"}}
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}
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val, err := p.declare(IDENT, lit)
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return val.(*Ident), err
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}
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func (p *parser) parseIdents() (mul Idents, err error) {
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for {
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one, err := p.parseIdent()
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if err != nil {
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return nil, err
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}
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mul = append(mul, one)
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if _, _, exi := p.mightBe(COMMA); !exi {
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break
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}
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}
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return
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}
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func (p *parser) parseTable() (*Table, error) {
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_, lit, err := p.shouldBe(IDENT)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"table"}}
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}
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val, err := p.declare(TABLE, lit)
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return val.(*Table), err
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}
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func (p *parser) parseTables() (mul Tables, err error) {
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for {
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one, err := p.parseTable()
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if err != nil {
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return nil, err
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}
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mul = append(mul, one)
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if _, _, exi := p.mightBe(COMMA); !exi {
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break
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}
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}
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return
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}
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func (p *parser) parseThing() (*Thing, error) {
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_, lit, err := p.shouldBe(THING)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"thing"}}
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}
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val, err := p.declare(THING, lit)
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return val.(*Thing), err
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}
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func (p *parser) parseThings() (mul Things, err error) {
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for {
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one, err := p.parseThing()
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if err != nil {
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return nil, err
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}
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mul = append(mul, one)
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if _, _, exi := p.mightBe(COMMA); !exi {
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break
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}
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}
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return
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}
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func (p *parser) parseIdiom() (*Ident, error) {
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_, lit, err := p.shouldBe(IDENT, EXPR)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"name, or expression"}}
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}
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val, err := p.declare(IDENT, lit)
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return val.(*Ident), err
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}
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func (p *parser) parseIdioms() (mul Idents, err error) {
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for {
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one, err := p.parseIdiom()
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if err != nil {
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return nil, err
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}
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mul = append(mul, one)
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if _, _, exi := p.mightBe(COMMA); !exi {
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break
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}
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}
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return
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}
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// --------------------------------------------------
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//
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// --------------------------------------------------
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func (p *parser) parseCond() (exp Expr, err error) {
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// The next token that we expect to see is a
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// WHERE token, and if we don't find one then
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// return nil, with no error.
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if _, _, exi := p.mightBe(WHERE); !exi {
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return nil, nil
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}
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return p.parseExpr()
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}
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// --------------------------------------------------
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//
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// --------------------------------------------------
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func (p *parser) parseRand() (exp []byte, err error) {
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exp = rand.New(128)
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return
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}
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// --------------------------------------------------
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//
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// --------------------------------------------------
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func (p *parser) parseArray() (Array, error) {
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_, lit, err := p.shouldBe(ARRAY)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"array"}}
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}
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val, err := p.declare(ARRAY, lit)
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return val.(Array), err
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}
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func (p *parser) parseObject() (Object, error) {
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_, lit, err := p.shouldBe(JSON)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"object"}}
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}
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val, err := p.declare(JSON, lit)
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return val.(Object), err
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}
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func (p *parser) parseNumber() (int64, error) {
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_, lit, err := p.shouldBe(NUMBER)
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if err != nil {
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return int64(0), &ParseError{Found: lit, Expected: []string{"number"}}
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}
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val, err := p.declare(NUMBER, lit)
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return val.(int64), err
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}
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func (p *parser) parseDouble() (float64, error) {
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_, lit, err := p.shouldBe(NUMBER, DOUBLE)
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if err != nil {
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return float64(0), &ParseError{Found: lit, Expected: []string{"number"}}
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}
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val, err := p.declare(DOUBLE, lit)
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return val.(float64), err
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}
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func (p *parser) parseString() (string, error) {
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_, lit, err := p.shouldBe(STRING)
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if err != nil {
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return string(""), &ParseError{Found: lit, Expected: []string{"string"}}
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}
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return lit, err
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}
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func (p *parser) parseRegion() (string, error) {
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_, lit, err := p.shouldBe(STRING, REGION)
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if err != nil {
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return string(""), &ParseError{Found: lit, Expected: []string{"string"}}
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}
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return lit, err
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}
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func (p *parser) parseBinary() ([]byte, error) {
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_, lit, err := p.shouldBe(STRING, REGION)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"string"}}
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}
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return []byte(lit), err
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}
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func (p *parser) parseScript() (string, error) {
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_, lit, err := p.shouldBe(STRING, REGION)
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if err != nil {
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return string(""), &ParseError{Found: lit, Expected: []string{"script"}}
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}
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return lit, err
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}
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func (p *parser) parseRegexp() (string, error) {
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tok, lit, err := p.shouldBe(REGEX)
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if err != nil {
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return string(""), &ParseError{Found: lit, Expected: []string{"regular expression"}}
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}
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val, err := p.declare(tok, lit)
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return val.(*regexp.Regexp).String(), err
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}
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func (p *parser) parseBoolean() (bool, error) {
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tok, lit, err := p.shouldBe(TRUE, FALSE)
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if err != nil {
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return bool(false), &ParseError{Found: lit, Expected: []string{"boolean"}}
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}
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val, err := p.declare(tok, lit)
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return val.(bool), err
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}
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func (p *parser) parseDuration() (time.Duration, error) {
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tok, lit, err := p.shouldBe(DURATION)
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if err != nil {
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return 0, &ParseError{Found: lit, Expected: []string{"duration"}}
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}
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val, err := p.declare(tok, lit)
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return val.(time.Duration), err
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}
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func (p *parser) parseTimeout() (time.Duration, error) {
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if _, _, exi := p.mightBe(TIMEOUT); !exi {
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return 0, nil
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}
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return p.parseDuration()
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}
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func (p *parser) parseBcrypt() ([]byte, error) {
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_, lit, err := p.shouldBe(STRING)
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if err != nil {
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return nil, &ParseError{Found: lit, Expected: []string{"string"}}
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}
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return bcrypt.GenerateFromPassword([]byte(lit), bcrypt.DefaultCost)
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}
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func (p *parser) parseAlgorithm() (string, error) {
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expected := []string{
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"ES256", "ES384", "ES512",
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"HS256", "HS384", "HS512",
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"PS256", "PS384", "PS512",
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"RS256", "RS384", "RS512",
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}
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_, lit, err := p.shouldBe(IDENT, STRING)
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if err != nil {
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return string(""), &ParseError{Found: lit, Expected: expected}
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}
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switch lit {
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case "ES256", "ES384", "ES512":
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case "HS256", "HS384", "HS512":
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case "PS256", "PS384", "PS512":
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case "RS256", "RS384", "RS512":
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default:
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return string(""), &ParseError{Found: lit, Expected: expected}
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}
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return lit, err
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}
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func (p *parser) parseExpr() (exp Expr, err error) {
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// Create the root binary expression tree.
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root := &BinaryExpression{}
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// If the subsequent token is an in, out, or
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// multi way path expression, then parse all
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// following expressions as a path.
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if tok, _, exi := p.mightBe(OEDGE, IEDGE, BEDGE); exi {
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return p.parsePath(tok)
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}
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// Begin with parsing the first expression
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// as the root of the tree to start with.
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root.RHS, err = p.parsePart()
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if err != nil {
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return nil, err
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}
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// If the subsequent token is an in, out, or
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// multi way path expression, then parse all
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// following expressions as a path.
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if tok, _, exi := p.mightBe(OEDGE, IEDGE, BEDGE); exi {
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return p.parsePath(root.RHS, tok)
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}
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// Loop over the operations and expressions
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// and build a binary expression tree based
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// on the precedence of the operators.
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for {
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var rhs Expr
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// Get the next token from the scanner and
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// the literal value that it is scanned as.
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tok, lit, _ := p.scan()
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switch tok {
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// If the token is an AND or OR expression
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// then skip to the next expression without
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// further checks.
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case AND, OR:
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// If the token is not an operator but can
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// be converted into an operator based on
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// logic, then convert it to an operator.
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case IN:
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tok = INS
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if _, _, exi := p.mightBe(NOT); exi {
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tok = NIS
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}
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case CONTAINS:
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tok = SIN
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if _, _, exi := p.mightBe(NOT); exi {
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tok = SNI
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}
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case IS:
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tok = EQ
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if _, _, exi := p.mightBe(NOT); exi {
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tok = NEQ
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}
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if _, _, exi := p.mightBe(IN); exi {
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switch tok {
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case EQ:
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tok = INS
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case NEQ:
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tok = NIS
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}
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}
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// If the token is a keyword which is also
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// actually an operator, then skip to the
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// next expression without further checks.
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case CONTAINSALL, CONTAINSNONE, CONTAINSSOME:
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case ALLCONTAINEDIN, NONECONTAINEDIN, SOMECONTAINEDIN:
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// If the token is an int64 or a float64 then
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// check to see whether the first rune is a
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// + or a - and use it as a token instead.
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case NUMBER, DOUBLE:
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switch lit[0] {
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case '-':
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rhs, err = p.declare(tok, lit[1:])
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tok = SUB
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case '+':
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rhs, err = p.declare(tok, lit[1:])
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tok = ADD
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default:
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p.unscan()
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return root.RHS, nil
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}
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// Check to see if the token is an operator
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// expression. If it is none of those then
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// unscan and break out of the loop.
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default:
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if !tok.isOperator() {
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p.unscan()
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return root.RHS, nil
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}
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}
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// If the token was not an int64 or float64
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// signed value then retrieve the next part
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// of the expression and add it to the right.
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if rhs == nil {
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rhs, err = p.parsePart()
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if err != nil {
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return nil, err
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}
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}
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// Find the right place in the tree to add the
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// new expression, by descending the right side
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// of the tree until we reach the last binary
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// expression, or until we reach an expression
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// whose operator precendence >= this precedence.
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for node := root; ; {
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r, ok := node.RHS.(*BinaryExpression)
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if !ok || r.Op.precedence() >= tok.precedence() {
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node.RHS = &BinaryExpression{LHS: node.RHS, Op: tok, RHS: rhs}
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break
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}
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node = r
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}
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}
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return root, err
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}
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func (p *parser) parsePart() (exp Expr, err error) {
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toks := []Token{
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MUL, ID, EXPR, IDENT, THING,
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NULL, VOID, EMPTY, MISSING,
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TRUE, FALSE, STRING, REGION, NUMBER, DOUBLE,
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NOW, DATE, TIME, DURATION, JSON, ARRAY, PARAM, LPAREN,
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}
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tok, lit, _ := p.scan()
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// We need to declare the type up here instead
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// of at the bottom, as the held value might
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// be overwritten by the next token scan.
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exp, err = p.declare(tok, lit)
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if err != nil {
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return nil, err
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}
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// If the current token is a left parenthesis
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// bracket, then we will parse this complete
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// expression part as a subquery.
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if p.is(tok, LPAREN) {
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return p.parseSubq()
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}
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// If the next token is a left parenthesis
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// bracket, then we will parse this complete
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// expression part as a function call.
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if _, _, exi := p.mightBe(LPAREN); exi {
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return p.parseCall(lit)
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}
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|
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// If this expression is not a subquery or a
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// function call, then check to see if the
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// token is in the list of allowed tokens.
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|
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if !p.in(tok, toks) {
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err = &ParseError{Found: lit, Expected: []string{"expression"}}
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}
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return
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}
|
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|
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func (p *parser) parseSubq() (sub *SubExpression, err error) {
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|
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var exp Expr
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var tok Token
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|
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tok, _, _ = p.mightBe(SELECT, CREATE, UPDATE, DELETE, RELATE)
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|
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switch tok {
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default:
|
|
exp, err = p.parseExpr()
|
|
case SELECT:
|
|
exp, err = p.parseSelectStatement()
|
|
case CREATE:
|
|
exp, err = p.parseCreateStatement()
|
|
case UPDATE:
|
|
exp, err = p.parseUpdateStatement()
|
|
case DELETE:
|
|
exp, err = p.parseDeleteStatement()
|
|
case RELATE:
|
|
exp, err = p.parseRelateStatement()
|
|
}
|
|
|
|
p.mightBe(RPAREN)
|
|
|
|
return &SubExpression{Expr: exp}, err
|
|
|
|
}
|
|
|
|
func (p *parser) parseCall(name string) (fnc *FuncExpression, err error) {
|
|
|
|
fnc = &FuncExpression{Name: name}
|
|
|
|
// Check to see if the immediate token
|
|
// is a right parenthesis bracket, and if
|
|
// it is then this function has no args.
|
|
|
|
if _, _, exi := p.mightBe(RPAREN); !exi {
|
|
|
|
for {
|
|
|
|
var arg Expr
|
|
|
|
arg, err = p.parseExpr()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Append the single expression to the array
|
|
// of function argument expressions.
|
|
|
|
fnc.Args = append(fnc.Args, arg)
|
|
|
|
// Check to see if the next token is a comma
|
|
// and if not, then break out of the loop,
|
|
// otherwise repeat until we find no comma.
|
|
|
|
if _, _, exi := p.mightBe(COMMA); !exi {
|
|
break
|
|
}
|
|
|
|
}
|
|
|
|
_, _, err = p.shouldBe(RPAREN)
|
|
|
|
}
|
|
|
|
// Check to see if the used function name is
|
|
// valid according to the currently supported
|
|
// functions. If not then return an error.
|
|
|
|
if _, ok := funcs[fnc.Name]; !ok {
|
|
|
|
return nil, &ParseError{
|
|
Found: fmt.Sprintf("%s()", name),
|
|
Expected: []string{"valid function name"},
|
|
}
|
|
|
|
}
|
|
|
|
// Check to see if the number of arguments
|
|
// is correct for the specified function name,
|
|
// and if not, then return an error.
|
|
|
|
if _, ok := funcs[fnc.Name][len(fnc.Args)]; !ok {
|
|
|
|
s, t := "", len(funcs[fnc.Name])
|
|
|
|
for i := 0; i < t; i++ {
|
|
switch {
|
|
case i > 0 && i == t-1:
|
|
s = s + " or "
|
|
case i > 0:
|
|
s = s + ", "
|
|
}
|
|
s = s + fmt.Sprintf("%d", i)
|
|
}
|
|
|
|
switch {
|
|
case t == 1:
|
|
s = s + " argument"
|
|
case t >= 2:
|
|
s = s + " arguments"
|
|
}
|
|
|
|
return nil, &ParseError{
|
|
Found: fmt.Sprintf("%s() with %d arguments", fnc.Name, len(fnc.Args)),
|
|
Expected: []string{s},
|
|
}
|
|
|
|
}
|
|
|
|
return
|
|
|
|
}
|
|
|
|
func (p *parser) parsePath(expr ...Expr) (path *PathExpression, err error) {
|
|
|
|
path = &PathExpression{}
|
|
|
|
// Take the previosuly scanned expression
|
|
// and append it to the path expression
|
|
// tree as the first item.
|
|
|
|
for _, e := range expr {
|
|
switch v := e.(type) {
|
|
case Token:
|
|
path.Expr = append(path.Expr, &JoinExpression{Join: v})
|
|
default:
|
|
path.Expr = append(path.Expr, &PartExpression{Part: v})
|
|
}
|
|
}
|
|
|
|
// If the last expression passed in was a
|
|
// path joiner (->, <-, or <->), then we
|
|
// need to process a path part first.
|
|
|
|
if _, ok := expr[len(expr)-1].(Token); ok {
|
|
|
|
var part Expr
|
|
|
|
part, err = p.parseStep()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if part == nil {
|
|
return
|
|
}
|
|
|
|
path.Expr = append(path.Expr, &PartExpression{Part: part})
|
|
|
|
}
|
|
|
|
for {
|
|
|
|
var join Expr
|
|
var part Expr
|
|
|
|
// We expect the next token to be a join
|
|
// operator (->, <-, or <->), otherwise we
|
|
// are at the end of the path and will
|
|
// ignore it and return.
|
|
|
|
join, err = p.parseJoin()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if join == nil {
|
|
return
|
|
}
|
|
|
|
path.Expr = append(path.Expr, &JoinExpression{Join: join.(Token)})
|
|
|
|
// We expect the next token to be a path
|
|
// part identifier, otherwise we are at
|
|
// the end of the path and will ignore it
|
|
// and return.
|
|
|
|
part, err = p.parseStep()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if part == nil {
|
|
return
|
|
}
|
|
|
|
path.Expr = append(path.Expr, &PartExpression{Part: part})
|
|
|
|
}
|
|
|
|
}
|
|
|
|
func (p *parser) parseJoin() (exp Expr, err error) {
|
|
|
|
toks := []Token{
|
|
OEDGE, IEDGE, BEDGE,
|
|
}
|
|
|
|
tok, _, _ := p.scan()
|
|
|
|
if !p.in(tok, toks) {
|
|
p.unscan()
|
|
return
|
|
}
|
|
|
|
return tok, err
|
|
|
|
}
|
|
|
|
func (p *parser) parseStep() (exp Expr, err error) {
|
|
|
|
toks := []Token{
|
|
QMARK, IDENT, THING, PARAM, LPAREN,
|
|
}
|
|
|
|
tok, lit, _ := p.scan()
|
|
|
|
// We need to declare the type up here instead
|
|
// of at the bottom, as the held value might
|
|
// be overwritten by the next token scan.
|
|
|
|
exp, err = p.declare(tok, lit)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// If the current token is a left parenthesis
|
|
// bracket, then we will parse this complete
|
|
// expression part as a subquery.
|
|
|
|
if p.is(tok, LPAREN) {
|
|
return p.parseSubp()
|
|
}
|
|
|
|
// If this expression is not a sub-path
|
|
// expression, then check to see if the
|
|
// token is in the list of allowed tokens.
|
|
|
|
if !p.in(tok, toks) {
|
|
p.unscan()
|
|
exp = nil
|
|
}
|
|
|
|
return
|
|
|
|
}
|
|
|
|
func (p *parser) parseSubp() (stmt *SubpExpression, err error) {
|
|
|
|
stmt = &SubpExpression{}
|
|
|
|
if stmt.What, err = p.parseWhat(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if _, _, exi := p.mightBe(AS); exi {
|
|
if stmt.Name, err = p.parseIdent(); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
if stmt.Cond, err = p.parseCond(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if _, _, err = p.shouldBe(RPAREN); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return
|
|
|
|
}
|