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Merge pull request #8289 from valtech-nyc/implement-smart-pipeline-in-parser

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Implement Smart Pipeline proposal in @babel/parser
This commit is contained in:
Sven Sauleau
2018-12-03 19:28:45 +01:00
committed by GitHub
parent fa9df678ac 100b38784d
commit fdc869ce16
158 changed files with 8496 additions and 86 deletions
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276
packages/babel-parser/src/parser/expression.js
View File

@@ -297,18 +297,21 @@ export default class ExpressionParser extends LValParser {
}
const op = this.state.type;
if (op === tt.nullishCoalescing) {
this.expectPlugin("nullishCoalescingOperator");
} else if (op === tt.pipeline) {
if (op === tt.pipeline) {
this.expectPlugin("pipelineOperator");
this.state.inPipeline = true;
this.checkPipelineAtInfixOperator(left, leftStartPos);
} else if (op === tt.nullishCoalescing) {
this.expectPlugin("nullishCoalescingOperator");
}
this.next();
const startPos = this.state.start;
const startLoc = this.state.startLoc;
if (op === tt.pipeline) {
if (
op === tt.pipeline &&
this.getPluginOption("pipelineOperator", "proposal") === "minimal"
) {
if (
this.match(tt.name) &&
this.state.value === "await" &&
@@ -321,13 +324,7 @@ export default class ExpressionParser extends LValParser {
}
}
node.right = this.parseExprOp(
this.parseMaybeUnary(),
startPos,
startLoc,
op.rightAssociative ? prec - 1 : prec,
noIn,
);
node.right = this.parseExprOpRightExpr(op, prec, noIn);
this.finishNode(
node,
@@ -337,6 +334,7 @@ export default class ExpressionParser extends LValParser {
? "LogicalExpression"
: "BinaryExpression",
);
return this.parseExprOp(
node,
leftStartPos,
@@ -349,6 +347,54 @@ export default class ExpressionParser extends LValParser {
return left;
}
// Helper function for `parseExprOp`. Parse the right-hand side of binary-
// operator expressions, then apply any operator-specific functions.
parseExprOpRightExpr(
op: TokenType,
prec: number,
noIn: ?boolean,
): N.Expression {
switch (op) {
case tt.pipeline:
if (this.getPluginOption("pipelineOperator", "proposal") === "smart") {
const startPos = this.state.start;
const startLoc = this.state.startLoc;
return this.withTopicPermittingContext(() => {
return this.parseSmartPipelineBody(
this.parseExprOpBaseRightExpr(op, prec, noIn),
startPos,
startLoc,
);
});
}
// falls through
default:
return this.parseExprOpBaseRightExpr(op, prec, noIn);
}
}
// Helper function for `parseExprOpRightExpr`. Parse the right-hand side of
// binary-operator expressions without applying any operator-specific functions.
parseExprOpBaseRightExpr(
op: TokenType,
prec: number,
noIn: ?boolean,
): N.Expression {
const startPos = this.state.start;
const startLoc = this.state.startLoc;
return this.parseExprOp(
this.parseMaybeUnary(),
startPos,
startLoc,
op.rightAssociative ? prec - 1 : prec,
noIn,
);
}
// Parse unary operators, both prefix and postfix.
parseMaybeUnary(refShorthandDefaultPos: ?Pos): N.Expression {
@@ -936,6 +982,32 @@ export default class ExpressionParser extends LValParser {
}
}
case tt.hash: {
if (this.state.inPipeline) {
node = this.startNode();
if (
this.getPluginOption("pipelineOperator", "proposal") !== "smart"
) {
this.raise(
node.start,
"Primary Topic Reference found but pipelineOperator not passed 'smart' for 'proposal' option.",
);
}
this.next();
if (this.primaryTopicReferenceIsAllowedInCurrentTopicContext()) {
this.registerTopicReference();
return this.finishNode(node, "PipelinePrimaryTopicReference");
} else {
throw this.raise(
node.start,
`Topic reference was used in a lexical context without topic binding`,
);
}
}
}
default:
throw this.unexpected();
}
@@ -2037,4 +2109,180 @@ export default class ExpressionParser extends LValParser {
}
return this.finishNode(node, "YieldExpression");
}
// Validates a pipeline (for any of the pipeline Babylon plugins) at the point
// of the infix operator `|>`.
checkPipelineAtInfixOperator(left: N.Expression, leftStartPos: number) {
if (this.getPluginOption("pipelineOperator", "proposal") === "smart") {
if (left.type === "SequenceExpression") {
// Ensure that the pipeline head is not a comma-delimited
// sequence expression.
throw this.raise(
leftStartPos,
`Pipeline head should not be a comma-separated sequence expression`,
);
}
}
}
parseSmartPipelineBody(
childExpression: N.Expression,
startPos: number,
startLoc: Position,
): N.PipelineBody {
const pipelineStyle = this.checkSmartPipelineBodyStyle(childExpression);
this.checkSmartPipelineBodyEarlyErrors(
childExpression,
pipelineStyle,
startPos,
);
return this.parseSmartPipelineBodyInStyle(
childExpression,
pipelineStyle,
startPos,
startLoc,
);
}
checkSmartPipelineBodyEarlyErrors(
childExpression: N.Expression,
pipelineStyle: N.PipelineStyle,
startPos: number,
): void {
if (this.match(tt.arrow)) {
// If the following token is invalidly `=>`, then throw a human-friendly error
// instead of something like 'Unexpected token, expected ";"'.
throw this.raise(
this.state.start,
`Unexpected arrow "=>" after pipeline body; arrow function in pipeline body must be parenthesized`,
);
} else if (
pipelineStyle === "PipelineTopicExpression" &&
childExpression.type === "SequenceExpression"
) {
throw this.raise(
startPos,
`Pipeline body may not be a comma-separated sequence expression`,
);
}
}
parseSmartPipelineBodyInStyle(
childExpression: N.Expression,
pipelineStyle: N.PipelineStyle,
startPos: number,
startLoc: Position,
): N.PipelineBody {
const bodyNode = this.startNodeAt(startPos, startLoc);
switch (pipelineStyle) {
case "PipelineBareFunction":
bodyNode.callee = childExpression;
break;
case "PipelineBareConstructor":
bodyNode.callee = childExpression.callee;
break;
case "PipelineBareAwaitedFunction":
bodyNode.callee = childExpression.argument;
break;
case "PipelineTopicExpression":
if (!this.topicReferenceWasUsedInCurrentTopicContext()) {
throw this.raise(
startPos,
`Pipeline is in topic style but does not use topic reference`,
);
}
bodyNode.expression = childExpression;
break;
default:
throw this.raise(startPos, `Unknown pipeline style ${pipelineStyle}`);
}
return this.finishNode(bodyNode, pipelineStyle);
}
checkSmartPipelineBodyStyle(expression: N.Expression): N.PipelineStyle {
switch (expression.type) {
default:
return this.isSimpleReference(expression)
? "PipelineBareFunction"
: "PipelineTopicExpression";
}
}
isSimpleReference(expression: N.Expression): boolean {
switch (expression.type) {
case "MemberExpression":
return (
!expression.computed && this.isSimpleReference(expression.object)
);
case "Identifier":
return true;
default:
return false;
}
}
// Enable topic references from outer contexts within smart pipeline bodies.
// The function modifies the parser's topic-context state to enable or disable
// the use of topic references with the smartPipelines plugin. They then run a
// callback, then they reset the parser to the old topic-context state that it
// had before the function was called.
withTopicPermittingContext<T>(callback: () => T): T {
const outerContextTopicState = this.state.topicContext;
this.state.topicContext = {
// Enable the use of the primary topic reference.
maxNumOfResolvableTopics: 1,
// Hide the use of any topic references from outer contexts.
maxTopicIndex: null,
};
try {
return callback();
} finally {
this.state.topicContext = outerContextTopicState;
}
}
// Disable topic references from outer contexts within syntax constructs
// such as the bodies of iteration statements.
// The function modifies the parser's topic-context state to enable or disable
// the use of topic references with the smartPipelines plugin. They then run a
// callback, then they reset the parser to the old topic-context state that it
// had before the function was called.
withTopicForbiddingContext<T>(callback: () => T): T {
const outerContextTopicState = this.state.topicContext;
this.state.topicContext = {
// Disable the use of the primary topic reference.
maxNumOfResolvableTopics: 0,
// Hide the use of any topic references from outer contexts.
maxTopicIndex: null,
};
try {
return callback();
} finally {
this.state.topicContext = outerContextTopicState;
}
}
// Register the use of a primary topic reference (`#`) within the current
// topic context.
registerTopicReference(): void {
this.state.topicContext.maxTopicIndex = 0;
}
primaryTopicReferenceIsAllowedInCurrentTopicContext(): boolean {
return this.state.topicContext.maxNumOfResolvableTopics >= 1;
}
topicReferenceWasUsedInCurrentTopicContext(): boolean {
return (
this.state.topicContext.maxTopicIndex != null &&
this.state.topicContext.maxTopicIndex >= 0
);
}
}

162
packages/babel-parser/src/parser/statement.js
View File

@@ -369,8 +369,18 @@ export default class StatementParser extends ExpressionParser {
parseDoStatement(node: N.DoWhileStatement): N.DoWhileStatement {
this.next();
this.state.labels.push(loopLabel);
node.body = this.parseStatement(false);
node.body =
// For the smartPipelines plugin: Disable topic references from outer
// contexts within the loop body. They are permitted in test expressions,
// outside of the loop body.
this.withTopicForbiddingContext(() =>
// Parse the loop body's body.
this.parseStatement(false),
);
this.state.labels.pop();
this.expect(tt._while);
node.test = this.parseParenExpression();
this.eat(tt.semi);
@@ -557,7 +567,17 @@ export default class StatementParser extends ExpressionParser {
} else {
clause.param = null;
}
clause.body = this.parseBlock();
clause.body =
// For the smartPipelines plugin: Disable topic references from outer
// contexts within the function body. They are permitted in function
// default-parameter expressions, which are part of the outer context,
// outside of the function body.
this.withTopicForbiddingContext(() =>
// Parse the catch clause's body.
this.parseBlock(false),
);
node.handler = this.finishNode(clause, "CatchClause");
}
@@ -585,8 +605,18 @@ export default class StatementParser extends ExpressionParser {
this.next();
node.test = this.parseParenExpression();
this.state.labels.push(loopLabel);
node.body = this.parseStatement(false);
node.body =
// For the smartPipelines plugin:
// Disable topic references from outer contexts within the loop body.
// They are permitted in test expressions, outside of the loop body.
this.withTopicForbiddingContext(() =>
// Parse loop body.
this.parseStatement(false),
);
this.state.labels.pop();
return this.finishNode(node, "WhileStatement");
}
@@ -596,7 +626,17 @@ export default class StatementParser extends ExpressionParser {
}
this.next();
node.object = this.parseParenExpression();
node.body = this.parseStatement(false);
node.body =
// For the smartPipelines plugin:
// Disable topic references from outer contexts within the function body.
// They are permitted in function default-parameter expressions, which are
// part of the outer context, outside of the function body.
this.withTopicForbiddingContext(() =>
// Parse the statement body.
this.parseStatement(false),
);
return this.finishNode(node, "WithStatement");
}
@@ -753,8 +793,18 @@ export default class StatementParser extends ExpressionParser {
this.expect(tt.semi);
node.update = this.match(tt.parenR) ? null : this.parseExpression();
this.expect(tt.parenR);
node.body = this.parseStatement(false);
node.body =
// For the smartPipelines plugin: Disable topic references from outer
// contexts within the loop body. They are permitted in test expressions,
// outside of the loop body.
this.withTopicForbiddingContext(() =>
// Parse the loop body.
this.parseStatement(false),
);
this.state.labels.pop();
return this.finishNode(node, "ForStatement");
}
@@ -778,8 +828,18 @@ export default class StatementParser extends ExpressionParser {
node.left = init;
node.right = this.parseExpression();
this.expect(tt.parenR);
node.body = this.parseStatement(false);
node.body =
// For the smartPipelines plugin:
// Disable topic references from outer contexts within the loop body.
// They are permitted in test expressions, outside of the loop body.
this.withTopicForbiddingContext(() =>
// Parse loop body.
this.parseStatement(false),
);
this.state.labels.pop();
return this.finishNode(node, type);
}
@@ -887,11 +947,18 @@ export default class StatementParser extends ExpressionParser {
}
this.parseFunctionParams(node);
this.parseFunctionBodyAndFinish(
node,
isStatement ? "FunctionDeclaration" : "FunctionExpression",
allowExpressionBody,
);
// For the smartPipelines plugin: Disable topic references from outer
// contexts within the function body. They are permitted in test
// expressions, outside of the function body.
this.withTopicForbiddingContext(() => {
// Parse the function body.
this.parseFunctionBodyAndFinish(
node,
isStatement ? "FunctionDeclaration" : "FunctionExpression",
allowExpressionBody,
);
});
this.state.inFunction = oldInFunc;
this.state.inMethod = oldInMethod;
@@ -966,44 +1033,49 @@ export default class StatementParser extends ExpressionParser {
this.expect(tt.braceL);
while (!this.eat(tt.braceR)) {
if (this.eat(tt.semi)) {
if (decorators.length > 0) {
// For the smartPipelines plugin: Disable topic references from outer
// contexts within the class body. They are permitted in test expressions,
// outside of the class body.
this.withTopicForbiddingContext(() => {
while (!this.eat(tt.braceR)) {
if (this.eat(tt.semi)) {
if (decorators.length > 0) {
this.raise(
this.state.lastTokEnd,
"Decorators must not be followed by a semicolon",
);
}
continue;
}
if (this.match(tt.at)) {
decorators.push(this.parseDecorator());
continue;
}
const member = this.startNode();
// steal the decorators if there are any
if (decorators.length) {
member.decorators = decorators;
this.resetStartLocationFromNode(member, decorators[0]);
decorators = [];
}
this.parseClassMember(classBody, member, state);
if (
member.kind === "constructor" &&
member.decorators &&
member.decorators.length > 0
) {
this.raise(
this.state.lastTokEnd,
"Decorators must not be followed by a semicolon",
member.start,
"Decorators can't be used with a constructor. Did you mean '@dec class { ... }'?",
);
}
continue;
}
if (this.match(tt.at)) {
decorators.push(this.parseDecorator());
continue;
}
const member = this.startNode();
// steal the decorators if there are any
if (decorators.length) {
member.decorators = decorators;
this.resetStartLocationFromNode(member, decorators[0]);
decorators = [];
}
this.parseClassMember(classBody, member, state);
if (
member.kind === "constructor" &&
member.decorators &&
member.decorators.length > 0
) {
this.raise(
member.start,
"Decorators can't be used with a constructor. Did you mean '@dec class { ... }'?",
);
}
}
});
if (decorators.length) {
this.raise(