977 lines
18 KiB
Go
977 lines
18 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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"sort"
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"time"
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"golang.org/x/text/language"
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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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exp, 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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mul = append(mul, exp)
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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) 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) 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) 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) 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) parsePriority() (float64, error) {
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tok, lit, err := p.shouldBe(NUMBER)
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if err != nil {
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return 0, &ParseError{Found: lit, Expected: []string{"number"}}
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}
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val, err := p.declare(tok, lit)
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return val.(float64), err
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}
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func (p *parser) parseType() (t, k string, err error) {
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_, t, err = p.shouldBe(IDENT, STRING, PASSWORD)
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if err != nil {
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err = &ParseError{Found: t, Expected: allowedTypes}
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return
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}
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if !contains(t, allowedTypes) {
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err = &ParseError{Found: t, Expected: allowedTypes}
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return
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}
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if t == "record" {
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if _, _, exi := p.mightBe(LPAREN); exi {
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if _, k, err = p.shouldBe(IDENT); err != nil {
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return
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}
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if _, _, err = p.shouldBe(RPAREN); err != nil {
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return
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}
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}
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}
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return
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}
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func (p *parser) parseLanguage() (language.Tag, error) {
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_, lit, err := p.shouldBe(IDENT, STRING)
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if err != nil {
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return language.English, &ParseError{Found: lit, Expected: []string{"string"}}
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}
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tag, err := language.Parse(lit)
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if err != nil {
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return language.English, &ParseError{Found: lit, Expected: []string{"BCP47 language"}}
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}
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if _, _, exi := p.mightBe(NUMERIC); exi {
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tag, _ = tag.SetTypeForKey("kn", "true")
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}
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return tag, err
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}
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func (p *parser) parseAlgorithm() (string, error) {
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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: allowedAlgorithms}
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}
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switch lit {
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case
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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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default:
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return string(""), &ParseError{Found: lit, Expected: allowedAlgorithms}
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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 primary token is an in, out, or
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// multi way path expression, then follow
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// the path through to the end.
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if tok, _, exi := p.mightBe(OEDGE, IEDGE, BEDGE); exi {
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root.RHS, err = p.parsePath(tok)
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if err != nil {
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return nil, err
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}
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} else {
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// Otherwise begin with parsing the first
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// expression, as the root of the tree.
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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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// But if the subsequent token is an in, out,
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// or multi way path expression, then follow
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// the path through to the end.
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if tok, _, exi := p.mightBe(DOT, OEDGE, IEDGE, BEDGE); exi {
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root.RHS, err = p.parsePath(root.RHS, tok)
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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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}
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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.parseExpr()
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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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if r, ok := rhs.(*BinaryExpression); ok {
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if r.Op.precedence() < tok.precedence() {
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r.LHS = &BinaryExpression{
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LHS: root.RHS,
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Op: tok,
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RHS: r.LHS,
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}
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node.RHS = rhs
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break
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}
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}
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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{
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LHS: node.RHS,
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Op: tok,
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RHS: rhs,
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}
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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 nil, nil
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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, EXPR, IDENT, THING, MODEL,
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NULL, VOID, EMPTY, MISSING,
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TRUE, FALSE, STRING, REGION, NUMBER, DOUBLE, REGEX,
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DATE, TIME, DURATION, JSON, ARRAY, PARAM, LPAREN, IF,
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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 IF word clause
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// then we will parse anything from here on
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// as an IF expression clause.
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if is(tok, IF) {
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return p.parseIfel()
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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 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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// 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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if !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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func (p *parser) parseSubq() (exp *SubExpression, err error) {
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exp = &SubExpression{}
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tok, _, _ := p.mightBe(SELECT, CREATE, UPDATE, DELETE, RELATE, INSERT, UPSERT)
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switch tok {
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case SELECT:
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exp.Expr, err = p.parseSelectStatement()
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case CREATE:
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p.buf.rw = true
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exp.Expr, err = p.parseCreateStatement()
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case UPDATE:
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p.buf.rw = true
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exp.Expr, err = p.parseUpdateStatement()
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case DELETE:
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p.buf.rw = true
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exp.Expr, err = p.parseDeleteStatement()
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case RELATE:
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p.buf.rw = true
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exp.Expr, err = p.parseRelateStatement()
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case INSERT:
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p.buf.rw = true
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exp.Expr, err = p.parseInsertStatement()
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case UPSERT:
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p.buf.rw = true
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exp.Expr, err = p.parseUpsertStatement()
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default:
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exp.Expr, err = p.parseExpr()
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}
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|
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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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_, _, err = p.shouldBe(RPAREN)
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return
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}
|
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|
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func (p *parser) parseMult() (exp *MultExpression, err error) {
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exp = &MultExpression{}
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if _, _, err = p.shouldBe(LPAREN); err != nil {
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return nil, err
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}
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|
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for {
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var stm Expr
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tok, _, _ := p.mightBe(IF, RUN, CREATE, UPDATE, DELETE, RELATE, INSERT, UPSERT)
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|
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switch tok {
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case IF:
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stm, err = p.parseIfel()
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case RUN:
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stm, err = p.parseRunStatement()
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case CREATE:
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p.buf.rw = true
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stm, err = p.parseCreateStatement()
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case UPDATE:
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p.buf.rw = true
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stm, err = p.parseUpdateStatement()
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case DELETE:
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p.buf.rw = true
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stm, err = p.parseDeleteStatement()
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case RELATE:
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p.buf.rw = true
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stm, err = p.parseRelateStatement()
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case INSERT:
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p.buf.rw = true
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stm, err = p.parseInsertStatement()
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case UPSERT:
|
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p.buf.rw = true
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stm, err = p.parseUpsertStatement()
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}
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|
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exp.Expr = append(exp.Expr, stm)
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|
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if _, _, exi := p.mightBe(SEMICOLON); !exi {
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break
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}
|
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|
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}
|
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|
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if _, _, err = p.shouldBe(RPAREN); err != nil {
|
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return nil, err
|
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}
|
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|
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return
|
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|
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}
|
|
|
|
func (p *parser) parseIfel() (exp *IfelExpression, err error) {
|
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|
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exp = &IfelExpression{}
|
|
|
|
for {
|
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|
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var tok Token
|
|
|
|
if cond, err := p.parseExpr(); err != nil {
|
|
return nil, err
|
|
} else {
|
|
exp.Cond = append(exp.Cond, cond)
|
|
}
|
|
|
|
if _, _, err = p.shouldBe(THEN); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if then, err := p.parseExpr(); err != nil {
|
|
return nil, err
|
|
} else {
|
|
exp.Then = append(exp.Then, then)
|
|
}
|
|
|
|
// Check to see if the next token is an
|
|
// ELSE keyword and if it is then check to
|
|
// see if there is another if statement.
|
|
|
|
if tok, _, err = p.shouldBe(ELSE, END); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if tok == END {
|
|
return
|
|
}
|
|
|
|
if tok == ELSE {
|
|
if _, _, exi := p.mightBe(IF); !exi {
|
|
break
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
if then, err := p.parseExpr(); err != nil {
|
|
return nil, err
|
|
} else {
|
|
exp.Else = then
|
|
}
|
|
|
|
if _, _, err = p.shouldBe(END); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return
|
|
|
|
}
|
|
|
|
func (p *parser) parseCall(name string) (fnc *FuncExpression, err error) {
|
|
|
|
fnc = &FuncExpression{Name: name}
|
|
|
|
// Check to see if this is an aggregate
|
|
// function, and if it is then mark it,
|
|
// so we can process it correcyly in the
|
|
// 'iterator' and 'document' layers.
|
|
|
|
if _, ok := aggrs[name]; ok {
|
|
fnc.Aggr = true
|
|
}
|
|
|
|
// 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 this function is allowed to
|
|
// have an undefined number of arguments, and
|
|
// if it is then skip argument checking.
|
|
|
|
if _, ok := funcs[fnc.Name][-1]; ok {
|
|
return
|
|
}
|
|
|
|
// 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, a, t := "", []int{}, len(funcs[fnc.Name])
|
|
|
|
for i := range funcs[fnc.Name] {
|
|
a = append(a, i)
|
|
}
|
|
|
|
sort.Ints(a)
|
|
|
|
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", a[i])
|
|
}
|
|
|
|
switch t {
|
|
case 1:
|
|
s = s + " argument"
|
|
default:
|
|
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) {
|
|
|
|
defer func() {
|
|
if val, ok := path.Expr[len(path.Expr)-1].(*JoinExpression); ok {
|
|
if val.Join == DOT {
|
|
err = &ParseError{
|
|
Found: fmt.Sprintf("."),
|
|
Expected: []string{"field expression"},
|
|
}
|
|
}
|
|
}
|
|
}()
|
|
|
|
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
|
|
}
|
|
|
|
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
|
|
}
|
|
|
|
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
|
|
}
|
|
|
|
if part == nil {
|
|
return
|
|
}
|
|
|
|
path.Expr = append(path.Expr, &PartExpression{Part: part})
|
|
|
|
}
|
|
|
|
}
|
|
|
|
func (p *parser) parseJoin() (exp Expr, err error) {
|
|
|
|
toks := []Token{
|
|
DOT, OEDGE, IEDGE, BEDGE,
|
|
}
|
|
|
|
tok, _, _ := p.scan()
|
|
|
|
if !in(tok, toks) {
|
|
p.unscan()
|
|
return
|
|
}
|
|
|
|
return tok, err
|
|
|
|
}
|
|
|
|
func (p *parser) parseStep() (exp Expr, err error) {
|
|
|
|
toks := []Token{
|
|
QMARK, IDENT, THING, LPAREN, EXPR, MUL,
|
|
}
|
|
|
|
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 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 !in(tok, toks) {
|
|
p.unscan()
|
|
exp = nil
|
|
}
|
|
|
|
return
|
|
|
|
}
|
|
|
|
func (p *parser) parseSubp() (stmt *SubpExpression, err error) {
|
|
|
|
stmt = &SubpExpression{}
|
|
|
|
// IMPORTANT maybe we should not accept any expression here
|
|
|
|
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
|
|
|
|
}
|