extract.go | Explore in Territory

func extractVariable(fset *token.FileSet, start, end token.Pos, src []byte, file *ast.File, pkg *types.Package, info *types.Info) (*token.FileSet, *analysis.SuggestedFix, error) { … }

// canExtractVariable reports whether the code in the given range can be
// extracted to a variable.
func canExtractVariable(info *types.Info, file *ast.File, start, end token.Pos) (ast.Expr, []ast.Node, bool, error) { … }

// Calculate indentation for insertion.
// When inserting lines of code, we must ensure that the lines have consistent
// formatting (i.e. the proper indentation). To do so, we observe the indentation on the
// line of code on which the insertion occurs.
func calculateIndentation(content []byte, tok *token.File, insertBeforeStmt ast.Node) (string, error) { … }

// generateAvailableName adjusts the new function name until there are no collisions in scope.
// Possible collisions include other function and variable names. Returns the next index to check for prefix.
func generateAvailableName(pos token.Pos, path []ast.Node, pkg *types.Package, info *types.Info, prefix string, idx int) (string, int) { … }

// generateNameOutsideOfRange is like generateAvailableName, but ignores names
// declared between start and end for the purposes of detecting conflicts.
//
// This is used for function extraction, where [start, end) will be extracted
// to a new scope.
func generateNameOutsideOfRange(start, end token.Pos, path []ast.Node, pkg *types.Package, info *types.Info, prefix string, idx int) (string, int) { … }

func generateName(idx int, prefix string, hasCollision func(string) bool) (string, int) { … }

type returnVariable …

// extractMethod refactors the selected block of code into a new method.
func extractMethod(fset *token.FileSet, start, end token.Pos, src []byte, file *ast.File, pkg *types.Package, info *types.Info) (*token.FileSet, *analysis.SuggestedFix, error) { … }

// extractFunction refactors the selected block of code into a new function.
func extractFunction(fset *token.FileSet, start, end token.Pos, src []byte, file *ast.File, pkg *types.Package, info *types.Info) (*token.FileSet, *analysis.SuggestedFix, error) { … }

// extractFunctionMethod refactors the selected block of code into a new function/method.
// It also replaces the selected block of code with a call to the extracted
// function. First, we manually adjust the selection range. We remove trailing
// and leading whitespace characters to ensure the range is precisely bounded
// by AST nodes. Next, we determine the variables that will be the parameters
// and return values of the extracted function/method. Lastly, we construct the call
// of the function/method and insert this call as well as the extracted function/method into
// their proper locations.
func extractFunctionMethod(fset *token.FileSet, start, end token.Pos, src []byte, file *ast.File, pkg *types.Package, info *types.Info, isMethod bool) (*token.FileSet, *analysis.SuggestedFix, error) { … }

// isSelector reports if e is the selector expr <x>, <sel>. It works for pointer and non-pointer selector expressions.
func isSelector(e ast.Expr, x, sel string) bool { … }

// reorderParams reorders the given parameters in-place to follow common Go conventions.
func reorderParams(params []ast.Expr, paramTypes []*ast.Field) { … }

func moveParamToFrontIfFound(params []ast.Expr, paramTypes []*ast.Field, x, sel string) { … }

// adjustRangeForCommentsAndWhiteSpace adjusts the given range to exclude unnecessary leading or
// trailing whitespace characters from selection as well as leading or trailing comments.
// In the following example, each line of the if statement is indented once. There are also two
// extra spaces after the sclosing bracket before the line break and a comment.
//
// \tif (true) {
// \t    _ = 1
// \t} // hello \n
//
// By default, a valid range begins at 'if' and ends at the first whitespace character
// after the '}'. But, users are likely to highlight full lines rather than adjusting
// their cursors for whitespace. To support this use case, we must manually adjust the
// ranges to match the correct AST node. In this particular example, we would adjust
// rng.Start forward to the start of 'if' and rng.End backward to after '}'.
func adjustRangeForCommentsAndWhiteSpace(tok *token.File, start, end token.Pos, content []byte, file *ast.File) (token.Pos, token.Pos, error) { … }

// isGoWhiteSpace returns true if b is a considered white space in
// Go as defined by scanner.GoWhitespace.
func isGoWhiteSpace(b byte) bool { … }

// findParent finds the parent AST node of the given target node, if the target is a
// descendant of the starting node.
func findParent(start ast.Node, target ast.Node) ast.Node { … }

type variable …

// collectFreeVars maps each identifier in the given range to whether it is "free."
// Given a range, a variable in that range is defined as "free" if it is declared
// outside of the range and neither at the file scope nor package scope. These free
// variables will be used as arguments in the extracted function. It also returns a
// list of identifiers that may need to be returned by the extracted function.
// Some of the code in this function has been adapted from tools/cmd/guru/freevars.go.
func collectFreeVars(info *types.Info, file *ast.File, fileScope, pkgScope *types.Scope, start, end token.Pos, node ast.Node) ([]*variable, error) { … }

// referencesObj checks whether the given object appears in the given expression.
func referencesObj(info *types.Info, expr ast.Expr, obj types.Object) bool { … }

type fnExtractParams …

// canExtractFunction reports whether the code in the given range can be
// extracted to a function.
func canExtractFunction(tok *token.File, start, end token.Pos, src []byte, file *ast.File) (*fnExtractParams, bool, bool, error) { … }

// objUsed checks if the object is used within the range. It returns the first
// occurrence of the object in the range, if it exists.
func objUsed(info *types.Info, start, end token.Pos, obj types.Object) (bool, *ast.Ident) { … }

// varOverridden traverses the given AST node until we find the given identifier. Then, we
// examine the occurrence of the given identifier and check for (1) whether the identifier
// is being redefined. If the identifier is free, we also check for (2) whether the identifier
// is being reassigned. We will not include an identifier in the return statement of the
// extracted function if it meets one of the above conditions.
func varOverridden(info *types.Info, firstUse *ast.Ident, obj types.Object, isFree bool, node ast.Node) bool { … }

// parseStmts parses the specified source (a list of statements) and
// returns them as a BlockStmt along with any associated comments.
func parseStmts(fset *token.FileSet, src []byte) (*ast.BlockStmt, []*ast.CommentGroup, error) { … }

// generateReturnInfo generates the information we need to adjust the return statements and
// signature of the extracted function. We prepare names, signatures, and "zero values" that
// represent the new variables. We also use this information to construct the if statement that
// is inserted below the call to the extracted function.
func generateReturnInfo(enclosing *ast.FuncType, pkg *types.Package, path []ast.Node, file *ast.File, info *types.Info, start, end token.Pos, hasNonNestedReturns bool) ([]*returnVariable, *ast.IfStmt, error) { … }

type objKey …

var conventionalVarNames …

// varNameForTypeName chooses a "good" name for a variable with the given type,
// if possible. Otherwise, it returns "", false.
//
// For special types, it uses known conventional names.
func varNameForType(t types.Type) (string, bool) { … }

// adjustReturnStatements adds "zero values" of the given types to each return statement
// in the given AST node.
func adjustReturnStatements(returnTypes []*ast.Field, seenVars map[types.Object]ast.Expr, file *ast.File, pkg *types.Package, extractedBlock *ast.BlockStmt) error { … }

// generateFuncCall constructs a call expression for the extracted function, described by the
// given parameters and return variables.
func generateFuncCall(hasNonNestedReturn, hasReturnVals bool, params, returns []ast.Expr, name string, token token.Token, selector string) ast.Node { … }

// initializeVars creates variable declarations, if needed.
// Our preference is to replace the selected block with an "x, y, z := fn()" style
// assignment statement. We can use this style when all of the variables in the
// extracted function's return statement are either not defined prior to the extracted block
// or can be safely redefined. However, for example, if z is already defined
// in a different scope, we replace the selected block with:
//
// var x int
// var y string
// x, y, z = fn()
func initializeVars(uninitialized []types.Object, retVars []*returnVariable, seenUninitialized map[types.Object]struct{ … }

// getNames returns the names from the given list of returnVariable.
func getNames(retVars []*returnVariable) []ast.Expr { … }

// getZeroVals returns the "zero values" from the given list of returnVariable.
func getZeroVals(retVars []*returnVariable) []ast.Expr { … }

// getDecls returns the declarations from the given list of returnVariable.
func getDecls(retVars []*returnVariable) []*ast.Field { … }
gotools/gopls/internal/golang/extract.go
