ExpressionBuilder

@webda/ql

---

Class: ExpressionBuilder

Defined in: packages/ql/src/query.ts:118

ANTLR parse tree visitor that builds an optimized Expression AST from the parsed tokens

Converts the ANTLR parse tree into a flat, evaluatable expression tree. Automatically flattens nested AND/OR expressions of the same type to reduce depth.

Extends

• AbstractParseTreeVisitor<Query>

Extended by

• PartialExpressionBuilder

Implements

• WebdaQLParserVisitor<any>

Constructors

Constructor

new ExpressionBuilder(): ExpressionBuilder

Returns

ExpressionBuilder

Inherited from

AbstractParseTreeVisitor<Query>.constructor

Properties

limit

limit: number

Defined in: packages/ql/src/query.ts:122

Parsed LIMIT value, if present

---

offset

offset: string

Defined in: packages/ql/src/query.ts:126

Parsed OFFSET continuation token, if present

---

orderBy

orderBy: OrderBy[]

Defined in: packages/ql/src/query.ts:130

Parsed ORDER BY clauses, if present

Methods

aggregateResult()

protected aggregateResult(aggregate, nextResult): Query

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:77

Aggregates the results of visiting multiple children of a node. After either all children are visited or #shouldVisitNextChild returns false, the aggregate value is returned as the result of #visitChildren.

The default implementation returns nextResult, meaning #visitChildren will return the result of the last child visited (or return the initial value if the node has no children).

Parameters

aggregate

Query

The previous aggregate value. In the default implementation, the aggregate value is initialized to #defaultResult, which is passed as the aggregate argument to this method after the first child node is visited.

nextResult

Query

The result of the immediately preceeding call to visit a child node.

Returns

Query

The updated aggregate result.

Inherited from

AbstractParseTreeVisitor.aggregateResult

---

defaultResult()

protected defaultResult(): Query

Defined in: packages/ql/src/query.ts:136

Default result when no expression is matched (empty AND, always true)

Returns

Query

an empty AND query

Overrides

AbstractParseTreeVisitor.defaultResult

---

getComparison()

getComparison(ctx): any[]

Defined in: packages/ql/src/query.ts:247

Recursively flatten nested logical expressions of the same type

ANTLR produces right-recursive trees like a AND (b AND (c AND d)). This method flattens them into [a, b, c, d] so a single LogicalExpression holds all children at one level.

Parameters

ctx

AndLogicExpressionContext | OrLogicExpressionContext

an AND or OR logical expression context

Returns

any[]

flat array of child parse tree nodes

---

getLimit()

getLimit(): number

Defined in: packages/ql/src/query.ts:155

Get parsed LIMIT value

Returns

number

the limit value

---

getOffset()

getOffset(): string

Defined in: packages/ql/src/query.ts:147

Get parsed OFFSET continuation token

Returns

string

the offset token

---

shouldVisitNextChild()

protected shouldVisitNextChild(node, currentResult): boolean

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:102

This method is called after visiting each child in #visitChildren. This method is first called before the first child is visited; at that point currentResult will be the initial value (in the default implementation, the initial value is returned by a call to #defaultResult. This method is not called after the last child is visited.

The default implementation always returns true, indicating that visitChildren should only return after all children are visited. One reason to override this method is to provide a "short circuit" evaluation option for situations where the result of visiting a single child has the potential to determine the result of the visit operation as a whole.

Parameters

node

RuleNode

The RuleNode whose children are currently being visited.

currentResult

Query

The current aggregate result of the children visited to the current point.

Returns

boolean

true to continue visiting children. Otherwise return false to stop visiting children and immediately return the current aggregate result from #visitChildren.

Inherited from

AbstractParseTreeVisitor.shouldVisitNextChild

---

visit()

visit(tree): Query

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:17

The default implementation calls ParseTree#accept on the specified tree.

Parameters

tree

ParseTree

Returns

Query

Implementation of

WebdaQLParserVisitor.visit

Inherited from

AbstractParseTreeVisitor.visit

---

visitAndLogicExpression()

visitAndLogicExpression(ctx): Expression

Defined in: packages/ql/src/query.ts:278

Get the AndExpression, regrouping all the parameters

By default the parser is doing a AND (b AND (c AND d)) creating 3 depth expressions This visitor simplify to a AND b AND c AND d with only one Expression

Parameters

ctx

AndLogicExpressionContext

the AND logic expression context

Returns

Expression

the flattened AndExpression

Implementation of

WebdaQLParserVisitor.visitAndLogicExpression

---

visitAtomExpression()

visitAtomExpression(ctx): Expression

Defined in: packages/ql/src/query.ts:377

A bare atom used as an expression: only TRUE / FALSE are valid

Parameters

ctx

AtomExpressionContext

the atom expression context

Returns

Expression

the constant expression

Throws

for identifiers, numbers and strings

Implementation of

WebdaQLParserVisitor.visitAtomExpression

---

visitBinaryComparisonExpression()

visitBinaryComparisonExpression(ctx): ComparisonExpression<ComparisonOperator>

Defined in: packages/ql/src/query.ts:290

Implement the BinaryComparison with all methods managed

Parameters

ctx

BinaryComparisonExpressionContext

the binary comparison context

Returns

ComparisonExpression<ComparisonOperator>

the comparison expression

Implementation of

WebdaQLParserVisitor.visitBinaryComparisonExpression

---

visitBooleanLiteral()

visitBooleanLiteral(ctx): boolean

Defined in: packages/ql/src/query.ts:399

Read the boolean literal

Parameters

ctx

BooleanLiteralContext

the boolean literal context

Returns

boolean

the boolean value

Implementation of

WebdaQLParserVisitor.visitBooleanLiteral

---

visitChildren()

visitChildren(node): Query

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:33

The default implementation initializes the aggregate result to #defaultResult defaultResult(). Before visiting each child, it calls #shouldVisitNextChild shouldVisitNextChild; if the result is false no more children are visited and the current aggregate result is returned. After visiting a child, the aggregate result is updated by calling #aggregateResult aggregateResult with the previous aggregate result and the result of visiting the child.

The default implementation is not safe for use in visitors that modify the tree structure. Visitors that modify the tree should override this method to behave properly in respect to the specific algorithm in use.

Parameters

node

RuleNode

Returns

Query

Implementation of

WebdaQLParserVisitor.visitChildren

Inherited from

AbstractParseTreeVisitor.visitChildren

---

visitContainsExpression()

visitContainsExpression(ctx): ComparisonExpression<"CONTAINS">

Defined in: packages/ql/src/query.ts:332

Map the a CONTAINS 'b'

Parameters

ctx

ContainsExpressionContext

the CONTAINS expression context

Returns

ComparisonExpression<"CONTAINS">

the comparison expression

Implementation of

WebdaQLParserVisitor.visitContainsExpression

---

visitErrorNode()

visitErrorNode(node): Query

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:47

The default implementation returns the result of #defaultResult defaultResult.

Parameters

node

ErrorNode

Returns

Query

Implementation of

WebdaQLParserVisitor.visitErrorNode

Inherited from

AbstractParseTreeVisitor.visitErrorNode

---

visitInExpression()

visitInExpression(ctx): ComparisonExpression<"IN">

Defined in: packages/ql/src/query.ts:321

Map the a IN ['b','c']

Parameters

ctx

InExpressionContext

the IN expression context

Returns

ComparisonExpression<"IN">

the comparison expression

Implementation of

WebdaQLParserVisitor.visitInExpression

---

visitIntegerLiteral()

visitIntegerLiteral(ctx): number

Defined in: packages/ql/src/query.ts:408

Read the number literal

Parameters

ctx

IntegerLiteralContext

the integer literal context

Returns

number

the parsed integer value

Implementation of

WebdaQLParserVisitor.visitIntegerLiteral

---

visitIsNotNullExpression()

visitIsNotNullExpression(ctx): ComparisonExpression<"IS NOT NULL">

Defined in: packages/ql/src/query.ts:352

Map the a IS NOT NULL

Parameters

ctx

IsNotNullExpressionContext

the IS NOT NULL expression context

Returns

ComparisonExpression<"IS NOT NULL">

the comparison expression

Implementation of

WebdaQLParserVisitor.visitIsNotNullExpression

---

visitIsNullExpression()

visitIsNullExpression(ctx): ComparisonExpression<"IS NULL">

Defined in: packages/ql/src/query.ts:343

Map the a IS NULL

Parameters

ctx

IsNullExpressionContext

the IS NULL expression context

Returns

ComparisonExpression<"IS NULL">

the comparison expression

Implementation of

WebdaQLParserVisitor.visitIsNullExpression

---

visitLikeExpression()

visitLikeExpression(ctx): ComparisonExpression<"LIKE">

Defined in: packages/ql/src/query.ts:310

Visit a LIKE expression (e.g. field LIKE '%pattern_')

Parameters

ctx

LikeExpressionContext

the LIKE expression context

Returns

ComparisonExpression<"LIKE">

the comparison expression

Implementation of

WebdaQLParserVisitor.visitLikeExpression

---

visitLimitExpression()

visitLimitExpression(ctx): void

Defined in: packages/ql/src/query.ts:163

Visit a LIMIT clause and store the integer value

Parameters

ctx

LimitExpressionContext

the limit expression context

Returns

void

Implementation of

WebdaQLParserVisitor.visitLimitExpression

---

visitNumberLiteral()

visitNumberLiteral(ctx): number

Defined in: packages/ql/src/query.ts:417

Read a signed or decimal number literal

Parameters

ctx

NumberLiteralContext

the number literal context

Returns

number

the parsed number

Implementation of

WebdaQLParserVisitor.visitNumberLiteral

---

visitOffsetExpression()

visitOffsetExpression(ctx): void

Defined in: packages/ql/src/query.ts:171

Visit an OFFSET clause and store the string continuation token

Parameters

ctx

OffsetExpressionContext

the offset expression context

Returns

void

Implementation of

WebdaQLParserVisitor.visitOffsetExpression

---

visitOrderExpression()

visitOrderExpression(ctx): void

Defined in: packages/ql/src/query.ts:191

Read the order by values

Parameters

ctx

OrderExpressionContext

the order expression context

Returns

void

Implementation of

WebdaQLParserVisitor.visitOrderExpression

---

visitOrderFieldExpression()

visitOrderFieldExpression(ctx): OrderBy

Defined in: packages/ql/src/query.ts:180

Visit a order field expression

Parameters

ctx

OrderFieldExpressionContext

the order field expression context

Returns

OrderBy

the parsed OrderBy

Implementation of

WebdaQLParserVisitor.visitOrderFieldExpression

---

visitOrLogicExpression()

visitOrLogicExpression(ctx): Expression

Defined in: packages/ql/src/query.ts:364

Get the OrExpression, regrouping all the parameters

By default the parser is doing a OR (b OR (c OR d)) creating 3 depth expressions This visitor simplify to a OR b OR c OR d with only one Expression

Parameters

ctx

OrLogicExpressionContext

the OR logic expression context

Returns

Expression

the flattened OrExpression

Implementation of

WebdaQLParserVisitor.visitOrLogicExpression

---

visitParameter()

visitParameter(ctx): never

Defined in: packages/ql/src/query.ts:426

A ? or :name placeholder reaching evaluation was never bound

Parameters

ctx

ParameterContext

the parameter context

Returns

never

Throws

always: use bind() or pass the parameters to query()

Implementation of

WebdaQLParserVisitor.visitParameter

---

visitSetExpression()

visitSetExpression(ctx): value[]

Defined in: packages/ql/src/query.ts:301

Visit each value of the [..., ..., ...] set

Parameters

ctx

SetExpressionContext

the set expression context

Returns

value[]

the array of values

Implementation of

WebdaQLParserVisitor.visitSetExpression

---

visitStringLiteral()

visitStringLiteral(ctx): string

Defined in: packages/ql/src/query.ts:390

Read a string literal, stripping the surrounding single or double quotes

Parameters

ctx

StringLiteralContext

the string literal context

Returns

string

the unquoted string value

Implementation of

WebdaQLParserVisitor.visitStringLiteral

---

visitTerminal()

visitTerminal(node): Query

Defined in: node_modules/.pnpm/antlr4ts@0.5.0-alpha.4/node_modules/antlr4ts/tree/AbstractParseTreeVisitor.d.ts:40

The default implementation returns the result of #defaultResult defaultResult.

Parameters

node

TerminalNode

Returns

Query

Implementation of

WebdaQLParserVisitor.visitTerminal

Inherited from

AbstractParseTreeVisitor.visitTerminal

---

visitWebdaql()

visitWebdaql(ctx): Query

Defined in: packages/ql/src/query.ts:205

Visit the root webdaql rule and build the complete Query

Parses filter expression, ORDER BY, LIMIT, and OFFSET clauses. Returns an empty AND expression (always true) when no filter is present.

Parameters

ctx

WebdaqlContext

the webdaql parse context

Returns

Query

the built Query

Implementation of

WebdaQLParserVisitor.visitWebdaql