Documentation
¶
Overview ¶
Package ast provides AST definition for GoCaml.
Example ¶
package main
import (
"fmt"
"github.com/rhysd/gocaml/token"
"github.com/rhysd/locerr"
)
// Visitor which counts number of nodes in AST
type printPath struct {
total int
}
// VisitTopdown method is called before children are visited
func (v *printPath) VisitTopdown(e Expr) Visitor {
fmt.Printf("\n -> %s (topdown)", e.Name())
return v
}
// VisitBottomup method is called after children were visited
func (v *printPath) VisitBottomup(e Expr) {
fmt.Printf("\n -> %s (bottomup)", e.Name())
}
func main() {
src := locerr.NewDummySource("")
// AST which usually comes from syntax.Parse() function.
rootOfAST := &Let{
LetToken: &token.Token{File: src},
Symbol: NewSymbol("test"),
Bound: &Int{
Token: &token.Token{File: src},
Value: 42,
},
Body: &Add{
Left: &VarRef{
Token: &token.Token{File: src},
Symbol: NewSymbol("test"),
},
Right: &Float{
Token: &token.Token{File: src},
Value: 3.14,
},
},
}
ast := &AST{Root: rootOfAST}
// Apply visitor to root node of AST
v := &printPath{0}
fmt.Println("ROOT")
Visit(v, ast.Root)
Output:
Index ¶
- func Fprint(out io.Writer, a *AST)
- func Print(a *AST)
- func Println(a *AST)
- func Visit(vis Visitor, e Expr)
- type AST
- type Add
- type And
- type Apply
- type ArrayGet
- type ArrayLit
- type ArrayMake
- type ArrayPut
- type ArraySize
- type Bool
- type CtorType
- type Div
- type Eq
- type Expr
- type External
- type FAdd
- type FDiv
- type FMul
- type FNeg
- type FSub
- type Float
- type FuncDef
- type FuncType
- type Greater
- type GreaterEq
- type If
- type Int
- type Less
- type LessEq
- type Let
- type LetRec
- type LetTuple
- type Match
- type Mod
- type Mul
- type Neg
- type None
- type Not
- type NotEq
- type Or
- type Param
- type Printer
- type Some
- type String
- type Sub
- type Symbol
- type Tuple
- type TupleType
- type TypeDecl
- type Typed
- type Unit
- type VarRef
- type Visitor
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type ArrayPut ¶
type ArrayPut struct {
Array, Index, Assignee Expr
}
AST node which meets Expr interface
type CtorType ¶
type CtorType struct {
StartToken *token.Token // Maybe nil
EndToken *token.Token
ParamTypes []Expr
Ctor *Symbol
}
Note: `int` has no param
type External ¶
type External struct {
StartToken *token.Token
EndToken *token.Token
Ident *Symbol
Type Expr
C string
}
AST node which meets Expr interface
type FuncDef ¶
func (*FuncDef) ParamSymbols ¶
type LetTuple ¶
type LetTuple struct {
LetToken *token.Token
Symbols []*Symbol
Bound, Body Expr
Type Expr // Maybe nil
}
AST node which meets Expr interface
type Match ¶
type Match struct {
StartToken *token.Token
Target Expr
IfSome, IfNone Expr
SomeIdent *Symbol
EndPos locerr.Pos
}
AST node which meets Expr interface
type Printer ¶
type Printer struct {
// contains filtered or unexported fields
}
Printer is a visitor to print AST to io.Writer
func (Printer) VisitBottomup ¶
func (Printer) VisitTopdown ¶
type Symbol ¶
Note: This struct cannot be replaced with string because there may be the same name symbol.
func IgnoredSymbol ¶
func IgnoredSymbol() *Symbol
type Visitor ¶
type Visitor interface {
// VisitTopdown defines the process when a node is visit. This method is called before
// children are visited.
// Returned value is a next visitor to use for succeeding visit. When wanting to stop
// visiting, please return nil.
// A visitor visits in depth-first order.
VisitTopdown(e Expr) Visitor
// VisitBottomup defines the process when a node is visit. This method is called after
// children were visited.
VisitBottomup(e Expr)
}
Visitor is an interface for the structs which is used for traversing AST.
Source Files
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