Luke Wilson
258b3c8e9b
- Add support for error sets and error union types - Implement for loops with index and payload syntax - Add defer, break, continue, and switch statements - Support unary expressions and array indexing - Add unreachable expression and test declarations - Extend AST with new type expressions (array, error union) - Update formatter to handle all new syntax elements - Fix formatting for switch prongs, payloads, and blocks
530 lines
11 KiB
Go
530 lines
11 KiB
Go
package zig
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"strings"
|
|
)
|
|
|
|
type formatter struct {
|
|
w io.Writer
|
|
line int // 1-based
|
|
col int // 1-based, reset to 1 after newline
|
|
indent int // indentation level
|
|
}
|
|
|
|
// indentStr defines the string used for each indentation level (4 spaces).
|
|
const indentStr = " "
|
|
|
|
// writef writes formatted text to the underlying writer and updates line/col counters.
|
|
// It also handles indentation after newlines when appropriate.
|
|
func (f *formatter) writef(format string, a ...any) {
|
|
s := fmt.Sprintf(format, a...)
|
|
for i, r := range s {
|
|
if r == '\n' {
|
|
f.line++
|
|
f.col = 1
|
|
// After a newline, write indentation for the next line unless it's a closing brace or another newline.
|
|
if i+1 < len(s) && s[i+1] != '\n' && s[i+1] != '}' {
|
|
f.writeIndent()
|
|
}
|
|
} else {
|
|
if f.col == 0 {
|
|
f.col = 1
|
|
} else {
|
|
f.col++
|
|
}
|
|
}
|
|
}
|
|
if _, err := f.w.Write([]byte(s)); err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
// writeIndent writes the current indentation level to the output.
|
|
// Call this at the start of a new line before writing statements or closing braces.
|
|
func (f *formatter) writeIndent() {
|
|
for i := 0; i < f.indent; i++ {
|
|
if _, err := f.w.Write([]byte(indentStr)); err != nil {
|
|
panic(err)
|
|
}
|
|
f.col += len(indentStr)
|
|
}
|
|
}
|
|
|
|
// Write is the entry point for formatting a Zig AST.
|
|
func Write(w io.Writer, root *Root) (err error) {
|
|
defer func() {
|
|
if r := recover(); r != nil {
|
|
if e, ok := r.(error); ok {
|
|
err = e
|
|
} else {
|
|
panic(r)
|
|
}
|
|
}
|
|
}()
|
|
sb := &strings.Builder{}
|
|
f := &formatter{w: sb, line: 1, col: 1, indent: 0}
|
|
|
|
if root.ContainerDocComment != "" {
|
|
f.writef("//! %s\n\n", root.ContainerDocComment)
|
|
}
|
|
for i, member := range root.ContainerMembers {
|
|
if member.Decl != nil {
|
|
// Only emit a leading newline before a function/global after the first declaration
|
|
if i > 0 {
|
|
f.writef("\n")
|
|
}
|
|
writeDecl(f, member.Decl)
|
|
}
|
|
}
|
|
out := sb.String()
|
|
if len(out) == 0 || out[len(out)-1] != '\n' {
|
|
out += "\n"
|
|
}
|
|
_, err = w.Write([]byte(out))
|
|
return err
|
|
}
|
|
|
|
// writeDecl emits a top-level declaration.
|
|
func writeDecl(f *formatter, decl Decl) {
|
|
switch d := decl.(type) {
|
|
case *FnDecl:
|
|
if d.Flags&FnExport != 0 {
|
|
f.writef("pub ")
|
|
}
|
|
f.writef("fn %s(", d.Name)
|
|
writeParams(f, d.Params)
|
|
f.writef(") ")
|
|
writeTypeExpr(f, d.ReturnType)
|
|
writeBlock(f, d.Body)
|
|
f.writef("\n")
|
|
case *GlobalVarDecl:
|
|
if d.Flags&GlobalVarConst != 0 {
|
|
f.writef("const %s = ", d.Name)
|
|
} else {
|
|
f.writef("var %s = ", d.Name)
|
|
}
|
|
writeExpr(f, d.Value)
|
|
f.writef(";\n")
|
|
case *ContainerDecl:
|
|
f.writef("struct ")
|
|
writeStructBody(f, d)
|
|
case *ErrorSetDecl:
|
|
writeExpr(f, d)
|
|
case *TestDecl:
|
|
f.writef("test ")
|
|
if d.Name != "" {
|
|
f.writef(`"%s"`, d.Name)
|
|
}
|
|
writeBlock(f, d.Block)
|
|
f.writef("\n")
|
|
}
|
|
}
|
|
|
|
// writeParams emits function parameters, separated by commas.
|
|
func writeParams(f *formatter, params []*ParamDecl) {
|
|
for i, param := range params {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
if param.Name != "" {
|
|
f.writef("%s: ", param.Name)
|
|
}
|
|
writeTypeExpr(f, param.Type)
|
|
}
|
|
}
|
|
|
|
// writeTypeExpr emits a type expression.
|
|
func writeTypeExpr(f *formatter, typ TypeExpr) {
|
|
switch t := typ.(type) {
|
|
case *Identifier:
|
|
f.writef("%s", t.Name)
|
|
case *PrefixTypeExpr:
|
|
f.writef("%s", t.Op)
|
|
writeTypeExpr(f, t.Base)
|
|
case *ArrayTypeExpr:
|
|
f.writef("[")
|
|
writeExpr(f, t.Size)
|
|
f.writef("]")
|
|
writeTypeExpr(f, t.Elem)
|
|
case *ErrorUnionTypeExpr:
|
|
writeTypeExpr(f, t.ErrSet)
|
|
f.writef("!")
|
|
writeTypeExpr(f, t.Type)
|
|
case nil:
|
|
// nothing
|
|
default:
|
|
f.writef("%v", t)
|
|
}
|
|
}
|
|
|
|
// writeBlock emits a block, handling indentation for statements and the closing brace.
|
|
func writeBlock(f *formatter, block *Block) {
|
|
if block == nil {
|
|
f.writef(";")
|
|
return
|
|
}
|
|
f.writef(" {\n")
|
|
f.indent++
|
|
for _, stmt := range block.Stmts {
|
|
f.writeIndent()
|
|
writeStmt(f, stmt)
|
|
f.writef("\n")
|
|
}
|
|
f.indent--
|
|
f.writeIndent()
|
|
f.writef("}")
|
|
}
|
|
|
|
// writeStmt emits a statement. Indentation is handled by the caller (writeBlock).
|
|
func writeStmt(f *formatter, stmt Stmt) {
|
|
switch s := stmt.(type) {
|
|
case *ReturnStmt:
|
|
f.writef("return")
|
|
if s.Value != nil {
|
|
f.writef(" ")
|
|
writeExpr(f, s.Value)
|
|
}
|
|
f.writef(";")
|
|
case *ExprStmt:
|
|
writeExpr(f, s.Expr)
|
|
f.writef(";")
|
|
case *VarDeclStmt:
|
|
if s.Const {
|
|
f.writef("const ")
|
|
} else {
|
|
f.writef("var ")
|
|
}
|
|
for i, name := range s.Pattern.Names {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
f.writef("%s", name)
|
|
}
|
|
if s.Type != nil {
|
|
f.writef(": ")
|
|
writeTypeExpr(f, s.Type)
|
|
}
|
|
if s.Value != nil {
|
|
f.writef(" = ")
|
|
writeExpr(f, s.Value)
|
|
}
|
|
f.writef(";")
|
|
case *BlockStmt:
|
|
writeBlock(f, s.Block)
|
|
case *IfStmt:
|
|
f.writef("if (")
|
|
writeExpr(f, s.Cond)
|
|
f.writef(")")
|
|
|
|
// Handle payload if present
|
|
if s.Payload != nil {
|
|
f.writef(" ")
|
|
writePayload(f, s.Payload)
|
|
}
|
|
|
|
// Always write the then branch as a block
|
|
if block, ok := s.Then.(*BlockStmt); ok {
|
|
writeBlock(f, block.Block)
|
|
} else {
|
|
f.writef(" ")
|
|
writeStmt(f, s.Then)
|
|
}
|
|
if s.Else != nil {
|
|
f.writef(" else")
|
|
if block, ok := s.Else.(*BlockStmt); ok {
|
|
writeBlock(f, block.Block)
|
|
} else {
|
|
f.writef(" ")
|
|
writeStmt(f, s.Else)
|
|
}
|
|
}
|
|
case *LoopStmt:
|
|
if s.Kind == "while" {
|
|
f.writef("while (")
|
|
if wp, ok := s.Prefix.(*WhilePrefix); ok {
|
|
writeExpr(f, wp.Cond)
|
|
if wp.Continue != nil {
|
|
f.writef(") : (")
|
|
writeExpr(f, wp.Continue)
|
|
}
|
|
}
|
|
f.writef(")")
|
|
// Always write the body as a block
|
|
if block, ok := s.Body.(*BlockStmt); ok {
|
|
writeBlock(f, block.Block)
|
|
} else {
|
|
f.writef(" ")
|
|
writeStmt(f, s.Body)
|
|
}
|
|
} else if s.Kind == "for" {
|
|
f.writef("for (")
|
|
if fp, ok := s.Prefix.(*ForPrefix); ok {
|
|
for i, arg := range fp.Args {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
writeExpr(f, arg.Expr)
|
|
if arg.From != nil {
|
|
if lit, ok := arg.From.(*Literal); ok && lit.Value == "" {
|
|
f.writef("..")
|
|
} else {
|
|
f.writef("...")
|
|
writeExpr(f, arg.From)
|
|
}
|
|
}
|
|
}
|
|
f.writef(")")
|
|
if fp.Payload != nil {
|
|
f.writef(" ")
|
|
writePayload(f, fp.Payload)
|
|
}
|
|
}
|
|
// Always write the body as a block
|
|
if block, ok := s.Body.(*BlockStmt); ok {
|
|
writeBlock(f, block.Block)
|
|
} else {
|
|
f.writef(" ")
|
|
writeStmt(f, s.Body)
|
|
}
|
|
}
|
|
case *DeferStmt:
|
|
if s.ErrDefer {
|
|
f.writef("errdefer")
|
|
} else {
|
|
f.writef("defer")
|
|
}
|
|
f.writef(" ")
|
|
writeStmt(f, s.Stmt)
|
|
case *BreakStmt:
|
|
f.writef("break")
|
|
if s.Label != "" {
|
|
f.writef(" :%s", s.Label)
|
|
}
|
|
if s.Value != nil {
|
|
f.writef(" ")
|
|
writeExpr(f, s.Value)
|
|
}
|
|
f.writef(";")
|
|
case *ContinueStmt:
|
|
f.writef("continue")
|
|
if s.Label != "" {
|
|
f.writef(" :%s", s.Label)
|
|
}
|
|
f.writef(";")
|
|
case *SwitchStmt:
|
|
f.writef("switch (")
|
|
writeExpr(f, s.Cond)
|
|
f.writef(") {\n")
|
|
f.indent++
|
|
for _, prong := range s.Prongs {
|
|
f.writeIndent()
|
|
writeSwitchProng(f, prong)
|
|
f.writef("\n")
|
|
}
|
|
f.indent--
|
|
f.writeIndent()
|
|
f.writef("}")
|
|
}
|
|
}
|
|
|
|
// writePayload emits a payload (|x|, |*x|, |*x, y|, etc).
|
|
func writePayload(f *formatter, payload *Payload) {
|
|
f.writef("|")
|
|
for i, name := range payload.Names {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
if payload.Pointers[i] {
|
|
f.writef("*")
|
|
}
|
|
f.writef("%s", name)
|
|
}
|
|
f.writef("|")
|
|
}
|
|
|
|
// writeSwitchProng emits a switch prong.
|
|
func writeSwitchProng(f *formatter, prong *SwitchProng) {
|
|
for i, c := range prong.Cases {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
if c.IsElse {
|
|
f.writef("else")
|
|
} else {
|
|
writeExpr(f, c.Expr)
|
|
if c.To != nil {
|
|
f.writef("...")
|
|
writeExpr(f, c.To)
|
|
}
|
|
}
|
|
}
|
|
f.writef(" => ")
|
|
// Check if the expression is actually a statement (like return or break)
|
|
if stmt, ok := prong.Expr.(Stmt); ok {
|
|
// If it's a block, write it directly without the leading space
|
|
if blockStmt, isBlock := stmt.(*BlockStmt); isBlock {
|
|
f.writef("{\n")
|
|
f.indent++
|
|
for _, s := range blockStmt.Block.Stmts {
|
|
f.writeIndent()
|
|
writeStmt(f, s)
|
|
f.writef("\n")
|
|
}
|
|
f.indent--
|
|
f.writeIndent()
|
|
f.writef("},")
|
|
} else {
|
|
// For single statements, write without the semicolon
|
|
switch s := stmt.(type) {
|
|
case *ReturnStmt:
|
|
f.writef("return")
|
|
if s.Value != nil {
|
|
f.writef(" ")
|
|
writeExpr(f, s.Value)
|
|
}
|
|
case *BreakStmt:
|
|
f.writef("break")
|
|
if s.Label != "" {
|
|
f.writef(" :%s", s.Label)
|
|
}
|
|
if s.Value != nil {
|
|
f.writef(" ")
|
|
writeExpr(f, s.Value)
|
|
}
|
|
case *ContinueStmt:
|
|
f.writef("continue")
|
|
if s.Label != "" {
|
|
f.writef(" :%s", s.Label)
|
|
}
|
|
case *ExprStmt:
|
|
writeExpr(f, s.Expr)
|
|
default:
|
|
writeStmt(f, stmt)
|
|
}
|
|
f.writef(",")
|
|
}
|
|
} else {
|
|
writeExpr(f, prong.Expr)
|
|
f.writef(",")
|
|
}
|
|
}
|
|
|
|
// writeExpr emits an expression.
|
|
func writeExpr(f *formatter, expr Expr) {
|
|
switch e := expr.(type) {
|
|
case *Identifier:
|
|
f.writef("%s", e.Name)
|
|
case *CallExpr:
|
|
writeExpr(f, e.Fun)
|
|
f.writef("(")
|
|
for i, arg := range e.Args {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
writeExpr(f, arg)
|
|
}
|
|
f.writef(")")
|
|
case *FieldAccessExpr:
|
|
writeExpr(f, e.Receiver)
|
|
f.writef(".%s", e.Field)
|
|
case *Literal:
|
|
switch e.Kind {
|
|
case "string":
|
|
f.writef(`"%v"`, e.Value)
|
|
default:
|
|
f.writef("%v", e.Value)
|
|
}
|
|
case *InitListExpr:
|
|
if e.Empty {
|
|
f.writef(".{}")
|
|
} else if len(e.Values) > 0 {
|
|
if len(e.Values) == 1 {
|
|
f.writef(".{")
|
|
writeExpr(f, e.Values[0])
|
|
f.writef("}")
|
|
} else {
|
|
f.writef(".{ ")
|
|
for i, v := range e.Values {
|
|
if i > 0 {
|
|
f.writef(", ")
|
|
}
|
|
writeExpr(f, v)
|
|
}
|
|
f.writef(" }")
|
|
}
|
|
}
|
|
case *ContainerDecl:
|
|
if e.Kind == "struct" {
|
|
f.writef("struct ")
|
|
writeStructBody(f, e)
|
|
} else {
|
|
panic("not implemented: " + e.Kind)
|
|
}
|
|
case *TryExpr:
|
|
f.writef("try ")
|
|
writeExpr(f, e.Expr)
|
|
case *BinaryExpr:
|
|
writeExpr(f, e.Left)
|
|
f.writef(" %s ", e.Op)
|
|
writeExpr(f, e.Right)
|
|
case *UnaryExpr:
|
|
f.writef("%s", e.Op)
|
|
writeExpr(f, e.Expr)
|
|
case *IndexExpr:
|
|
writeExpr(f, e.Receiver)
|
|
f.writef("[")
|
|
writeExpr(f, e.Index)
|
|
f.writef("]")
|
|
case *UnreachableExpr:
|
|
f.writef("unreachable")
|
|
case *ErrorSetDecl:
|
|
f.writef("error{\n")
|
|
f.indent++
|
|
for _, name := range e.Names {
|
|
f.writeIndent()
|
|
f.writef("%s,\n", name)
|
|
}
|
|
f.indent--
|
|
f.writeIndent()
|
|
f.writef("}")
|
|
}
|
|
}
|
|
|
|
// writeStructBody emits the body of a struct/union/enum/opaque declaration.
|
|
func writeStructBody(f *formatter, decl *ContainerDecl) {
|
|
f.writef("{\n")
|
|
f.indent++
|
|
for _, member := range decl.Fields {
|
|
if member.Field != nil {
|
|
// Field or const
|
|
if member.Field.Type == nil && member.Field.Value != nil {
|
|
// const field
|
|
f.writeIndent()
|
|
f.writef("const %s = ", member.Field.Name)
|
|
writeExpr(f, member.Field.Value)
|
|
f.writef(";\n")
|
|
} else {
|
|
// regular field
|
|
f.writeIndent()
|
|
f.writef("%s: ", member.Field.Name)
|
|
writeTypeExpr(f, member.Field.Type)
|
|
if member.Field.Value != nil {
|
|
f.writef(" = ")
|
|
writeExpr(f, member.Field.Value)
|
|
}
|
|
f.writef(",\n")
|
|
}
|
|
} else if member.Decl != nil {
|
|
// Method or nested decl
|
|
f.writef("\n")
|
|
f.writeIndent()
|
|
writeDecl(f, member.Decl)
|
|
}
|
|
}
|
|
f.indent--
|
|
f.writeIndent()
|
|
f.writef("}")
|
|
}
|