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converter.go
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// (Try to!) convert a Turbo Pascal AST into Go code
package main
import (
"fmt"
"io"
"strings"
)
func Convert(file File, units []*Unit, w io.Writer) {
c := &converter{w: w}
c.units = make(map[string]*Unit)
for _, unit := range units {
c.units[strings.ToLower(unit.Name)] = unit
}
c.types = make(map[string]TypeSpec)
c.pushScope(ScopeGlobal)
// Builtin functions (or those in VIDEO.PAS)
c.defineVar("Chr", &FuncSpec{
[]*ParamGroup{{false, []string{"x"}, &TypeIdent{"byte"}}},
&TypeIdent{"string"},
})
c.defineVar("Copy", &FuncSpec{
[]*ParamGroup{
{false, []string{"s"}, &TypeIdent{"string"}},
{false, []string{"index", "count"}, &TypeIdent{"integer"}},
},
&TypeIdent{"string"},
})
c.defineVar("GetTime", &ProcSpec{[]*ParamGroup{
{true, []string{"h", "m", "s", "s100"}, &TypeIdent{"uint16"}},
}})
c.defineVar("IOResult", &FuncSpec{
nil,
&TypeIdent{"integer"},
})
c.defineVar("KeyPressed", &FuncSpec{
nil,
&TypeIdent{"boolean"},
})
c.defineVar("Length", &FuncSpec{
[]*ParamGroup{{false, []string{"s"}, &TypeIdent{"string"}}},
&TypeIdent{"integer"},
})
c.defineVar("Port", &ArraySpec{
Min: &ConstExpr{0, false},
Max: &ConstExpr{1000, false},
Of: &IdentSpec{&TypeIdent{"integer"}},
})
c.defineVar("Random", &FuncSpec{
[]*ParamGroup{{false, []string{"end"}, &TypeIdent{"integer"}}},
&TypeIdent{"integer"},
})
c.defineVar("ReadKey", &FuncSpec{
nil,
&TypeIdent{"char"},
})
c.defineVar("Sqr", &FuncSpec{
[]*ParamGroup{{false, []string{"n"}, &TypeIdent{"integer"}}},
&TypeIdent{"integer"},
})
c.defineVar("Trunc", &FuncSpec{
[]*ParamGroup{{false, []string{"x"}, &TypeIdent{"real"}}},
&TypeIdent{"integer"},
})
c.defineVar("UpCase", &FuncSpec{
[]*ParamGroup{{false, []string{"ch"}, &TypeIdent{"char"}}},
&TypeIdent{"char"},
})
c.defineVar("VideoMove", &ProcSpec{[]*ParamGroup{
{false, []string{"x", "y", "chars"}, &TypeIdent{"integer"}},
{false, []string{"data"}, &TypeIdent{"pointer"}},
{false, []string{"toVideo"}, &TypeIdent{"boolean"}},
}})
c.defineVar("VideoWriteText", &ProcSpec{[]*ParamGroup{
{false, []string{"x", "y"}, &TypeIdent{"integer"}},
{false, []string{"color"}, &TypeIdent{"byte"}},
{false, []string{"text"}, &TypeIdent{"string"}},
}})
c.defineType("TVideoLine", &StringSpec{80})
switch file := file.(type) {
case *Program:
c.program(file)
case *Unit:
c.unit(file)
default:
panic(fmt.Sprintf("unhandled File type: %T", file))
}
}
type converter struct {
units map[string]*Unit
w io.Writer
types map[string]TypeSpec
scopes []Scope
}
type Scope struct {
Type ScopeType
WithName string
WithExpr Expr
Vars map[string]TypeSpec
VarParams map[string]struct{}
}
type ScopeType int
const (
ScopeNone ScopeType = iota
ScopeGlobal
ScopeLocal
ScopeWith
)
func (c *converter) pushScope(typ ScopeType) {
scope := Scope{
Type: typ,
Vars: make(map[string]TypeSpec),
VarParams: make(map[string]struct{}),
}
c.scopes = append(c.scopes, scope)
}
func (c *converter) pushWithScope(withName string, withExpr Expr) {
c.pushScope(ScopeWith)
c.scopes[len(c.scopes)-1].WithName = withName
c.scopes[len(c.scopes)-1].WithExpr = withExpr
}
func (c *converter) popScope() {
c.scopes = c.scopes[:len(c.scopes)-1]
}
func (c *converter) defineVar(name string, spec TypeSpec) {
scope := c.scopes[len(c.scopes)-1]
scope.Vars[strings.ToLower(name)] = spec
}
func (c *converter) defineWithVar(name string) {
for i := len(c.scopes) - 1; i >= 0; i-- {
scope := c.scopes[i]
if scope.Type != ScopeWith {
scope.Vars[strings.ToLower(name)] = &IdentSpec{&TypeIdent{name}}
return
}
}
}
func (c *converter) defineType(name string, spec TypeSpec) {
c.types[strings.ToLower(name)] = spec
}
func (c *converter) lookupType(name string) TypeSpec {
return c.types[strings.ToLower(name)]
}
func (c *converter) lookupVarType(name string) (Scope, TypeSpec) {
name = strings.ToLower(name)
for i := len(c.scopes) - 1; i >= 0; i-- {
scope := c.scopes[i]
spec := scope.Vars[name]
if spec != nil {
return scope, spec
}
}
return Scope{}, nil
}
func (c *converter) setVarParam(name string) {
scope := c.scopes[len(c.scopes)-1]
scope.VarParams[strings.ToLower(name)] = struct{}{}
}
func (c *converter) isVarParam(name string) bool {
name = strings.ToLower(name)
for i := len(c.scopes) - 1; i >= 0; i-- {
scope := c.scopes[i]
_, isVar := scope.VarParams[name]
if isVar {
return true
}
}
return false
}
func (c *converter) lookupVarExprType(expr Expr) (TypeSpec, string) {
var spec TypeSpec
fieldName := ""
switch expr := expr.(type) {
case *AtExpr:
spec, fieldName = c.lookupVarExprType(expr.Expr)
case *DotExpr:
fieldName = expr.Field
spec, _ = c.lookupVarExprType(expr.Record)
if spec == nil {
return nil, ""
}
spec = findField(spec.(*RecordSpec), expr.Field)
if spec == nil {
panic(fmt.Sprintf("field not found: %q", expr.Field))
}
case *IdentExpr:
scope, varSpec := c.lookupVarType(expr.Name)
if varSpec != nil && scope.Type == ScopeWith {
fullExpr := &DotExpr{scope.WithExpr, expr.Name}
return c.lookupVarExprType(fullExpr)
}
fieldName = expr.Name
_, spec = c.lookupVarType(expr.Name)
case *IndexExpr:
spec, fieldName = c.lookupVarExprType(expr.Array)
switch specTyped := spec.(type) {
case *ArraySpec:
spec = specTyped.Of
case *StringSpec, *IdentSpec:
case *PointerSpec:
spec = &IdentSpec{specTyped.Type}
default:
panic(fmt.Sprintf("unexpected index type: %s", spec))
}
case *PointerExpr:
spec, fieldName = c.lookupVarExprType(expr.Expr)
case *FuncExpr:
default:
panic(fmt.Sprintf("unexpected varExpr type: %T", expr))
}
if spec != nil {
spec = c.lookupIdentSpec(spec)
}
return spec, fieldName
}
func (c *converter) lookupIdentSpec(spec TypeSpec) TypeSpec {
ident, isIdent := spec.(*IdentSpec)
if !isIdent {
return spec
}
n := strings.ToLower(ident.Type.Name)
if n == "byte" || n == "char" || n == "boolean" || n == "integer" || n == "word" || n == "real" || n == "string" {
return spec // builtin type
}
spec = c.lookupType(ident.Type.Name)
if spec == nil {
return nil
}
return spec
}
func (c *converter) lookupNamedType(spec TypeSpec) TypeSpec {
if a, ok := spec.(*ArraySpec); ok {
spec = a.Of
}
typeName := spec.(*IdentSpec).Type.Name
spec = c.lookupType(typeName)
if spec == nil {
panic(fmt.Sprintf("named type not found: %q", typeName))
}
return spec
}
func findField(record *RecordSpec, field string) TypeSpec {
for _, section := range record.Sections {
for _, name := range section.Names {
if name == field {
return section.Type
}
}
}
return nil
}
func (c *converter) print(a ...interface{}) {
fmt.Fprint(c.w, a...)
}
func (c *converter) printf(format string, a ...interface{}) {
fmt.Fprintf(c.w, format, a...)
}
func (c *converter) printChar(b byte) {
switch b {
case '\\':
c.print(`'\\'`)
case '\'':
c.print(`'\''`)
case '\n':
c.print(`'\n'`)
case '\r':
c.print(`'\r'`)
case '\t':
c.print(`'\t'`)
default:
if b < 32 || b > 126 {
c.printf(`'\x%02x'`, b)
return
}
c.printf("'%c'", b)
}
}
func (c *converter) program(program *Program) {
c.print("package main\n\n")
if program.Uses != nil {
c.printf("// uses: %s\n\n", strings.Join(program.Uses, ", "))
for _, unitName := range program.Uses {
c.addUnitDecls(unitName)
}
}
c.decls(program.Decls, true)
c.defineDecls(program.Decls)
c.print("func main() {\n")
c.stmts(program.Stmt.Stmts)
c.print("}\n")
}
func (c *converter) addUnitDecls(unitName string) {
unit, loaded := c.units[strings.ToLower(unitName)]
if !loaded {
return
}
c.defineDecls(unit.Interface)
}
func (c *converter) defineDecls(decls []DeclPart) {
for _, decl := range decls {
switch decl := decl.(type) {
case *TypeDefs:
for _, d := range decl.Defs {
c.defineType(d.Name, d.Type)
}
case *VarDecls:
for _, d := range decl.Decls {
for _, name := range d.Names {
c.defineVar(name, d.Type)
}
}
case *ConstDecls:
for _, d := range decl.Decls {
c.defineVar(d.Name, d.Type)
}
case *ProcDecl:
c.defineVar(decl.Name, &ProcSpec{decl.Params})
case *FuncDecl:
c.defineVar(decl.Name, &FuncSpec{decl.Params, decl.Result})
}
}
}
func (c *converter) defineParams(params []*ParamGroup) {
for _, group := range params {
for _, name := range group.Names {
c.defineVar(name, &IdentSpec{group.Type})
if group.IsVar {
c.setVarParam(name)
}
}
}
}
func (c *converter) unit(unit *Unit) {
c.printf("package main // unit: %s\n\n", unit.Name)
if unit.InterfaceUses != nil {
c.printf("// interface uses: %s\n\n", strings.Join(unit.InterfaceUses, ", "))
for _, unitName := range unit.InterfaceUses {
c.addUnitDecls(unitName)
}
}
c.defineDecls(unit.Interface)
c.decls(unit.Interface, true)
if unit.ImplementationUses != nil {
c.printf("\n// implementation uses: %s\n\n", strings.Join(unit.ImplementationUses, ", "))
for _, unitName := range unit.ImplementationUses {
c.addUnitDecls(unitName)
}
}
c.defineDecls(unit.Implementation)
c.decls(unit.Implementation, true)
initEmpty := true
for _, stmt := range unit.Init.Stmts {
if _, isEmpty := stmt.(*EmptyStmt); !isEmpty {
initEmpty = false
}
}
if !initEmpty {
c.print("func init() {\n")
c.stmts(unit.Init.Stmts)
c.print("}\n")
}
}
func (c *converter) decls(decls []DeclPart, isMain bool) {
for _, decl := range decls {
c.decl(decl, isMain)
}
}
func (c *converter) decl(decl DeclPart, isMain bool) {
switch decl := decl.(type) {
case *ConstDecls:
consts := []*ConstDecl{}
vars := []*ConstDecl{}
for _, d := range decl.Decls {
switch d.Value.(type) {
case *ConstArrayExpr, *ConstRecordExpr:
vars = append(vars, d)
default:
consts = append(consts, d)
}
}
if len(consts) > 0 {
if len(consts) == 1 {
c.print("const ")
} else {
c.print("const (\n")
}
for _, d := range consts {
c.printf("%s", d.Name)
if d.Type != nil {
c.print(" ")
c.typeSpec(d.Type)
}
c.print(" = ")
c.expr(d.Value)
c.print("\n")
}
if len(consts) != 1 {
c.print(")\n")
}
}
if len(vars) > 0 {
if len(vars) == 1 {
c.print("var ")
} else {
c.print("var (\n")
}
for _, d := range vars {
c.printf("%s ", d.Name)
c.typeSpec(d.Type)
c.print(" = ")
switch d.Value.(type) {
case *ConstRecordExpr:
c.typeSpec(d.Type)
case *ConstArrayExpr:
c.typeSpec(d.Type)
}
c.expr(d.Value)
c.print("\n")
}
if len(vars) != 1 {
c.print(")\n")
}
}
case *FuncDecl:
if decl.Stmt == nil {
return
}
if isMain {
c.printf("func %s(", decl.Name)
} else {
c.printf("%s := func(", decl.Name)
}
c.params(decl.Params)
c.printf(") (%s ", decl.Name)
c.typeIdent(decl.Result)
c.print(") {\n")
c.pushScope(ScopeLocal)
c.defineParams(decl.Params)
c.defineDecls(decl.Decls)
c.decls(decl.Decls, false)
c.stmts(decl.Stmt.Stmts)
c.popScope()
c.print("return\n}\n\n")
case *LabelDecls:
// not needed
case *ProcDecl:
if decl.Stmt == nil {
return
}
if isMain {
c.printf("func %s(", decl.Name)
} else {
c.printf("%s := func(", decl.Name)
}
c.params(decl.Params)
c.print(") {\n")
c.pushScope(ScopeLocal)
c.defineParams(decl.Params)
c.defineDecls(decl.Decls)
c.decls(decl.Decls, false)
c.stmts(decl.Stmt.Stmts)
c.popScope()
c.print("}\n\n")
case *TypeDefs:
if len(decl.Defs) == 1 {
c.print("type ")
} else {
c.print("type (\n")
}
var scalarType string
var scalarConsts []string
for _, d := range decl.Defs {
c.printf("%s ", d.Name)
if spec, ok := d.Type.(*ScalarSpec); ok {
scalarType = d.Name
scalarConsts = spec.Names
}
c.typeSpec(d.Type)
c.print("\n")
}
if len(decl.Defs) != 1 {
c.print(")\n")
}
if scalarConsts != nil {
// Add constants from last ScalarSpec "enum". Bit of a
// hack, as it only supports one "enum" per defs, but
// that's all we need for ZZT source.
c.print("const (\n")
for i, name := range scalarConsts {
c.printf("%s", name)
if i == 0 {
c.printf(" %s = iota + 1", scalarType)
}
c.print("\n")
}
c.print(")\n\n")
}
case *VarDecls:
if len(decl.Decls) == 1 {
c.print("var ")
} else {
c.print("var (\n")
}
for _, d := range decl.Decls {
c.printf("%s ", strings.Join(d.Names, ", "))
c.typeSpec(d.Type)
c.print("\n")
}
if len(decl.Decls) != 1 {
c.print(")\n")
}
default:
panic(fmt.Sprintf("unhandled DeclPart type: %T", decl))
}
}
func (c *converter) params(params []*ParamGroup) {
for i, param := range params {
if i > 0 {
c.print(", ")
}
c.print(strings.Join(param.Names, ", "), " ")
if param.IsVar {
c.print("*")
}
c.typeIdent(param.Type)
}
}
func (c *converter) typeIdent(typ *TypeIdent) {
refSpec := c.lookupType(typ.Name)
if _, isStr := refSpec.(*StringSpec); isStr {
c.print("string")
return
}
var s string
switch strings.ToLower(typ.Name) {
case "byte", "char":
s = "byte"
case "boolean":
s = "bool"
case "integer":
s = "int16"
case "real":
s = "float64"
case "string":
s = "string"
case "pointer":
s = "*uintptr"
case "word":
s = "uint16"
case "longint":
s = "int32"
default:
s = typ.Name
}
c.print(s)
}
func (c *converter) stmts(stmts []Stmt) {
for _, stmt := range stmts {
c.stmt(stmt)
}
}
func (c *converter) stmtNoBraces(stmt Stmt) {
switch stmt := stmt.(type) {
case *CompoundStmt:
c.stmts(stmt.Stmts)
default:
c.stmt(stmt)
}
}
func (c *converter) stmt(stmt Stmt) {
switch stmt := stmt.(type) {
case *AssignStmt:
c.varExpr(stmt.Var, false)
// Simplify expressions like "x := x + n"
binary, isBinary := stmt.Value.(*BinaryExpr)
if isBinary && (binary.Op == PLUS || binary.Op == MINUS) {
if stmt.Var.String() == binary.Left.String() {
cnst, isConst := binary.Right.(*ConstExpr)
if isConst {
intVal, isInt := cnst.Value.(int)
if isInt && intVal == 1 {
if binary.Op == PLUS {
c.print("++")
} else {
c.print("--")
}
break
}
}
c.printf(" %s= ", operatorStr(binary.Op))
c.assignRhs(stmt.Var, binary.Right)
break
}
}
c.print(" = ")
c.assignRhs(stmt.Var, stmt.Value)
case *CaseStmt:
c.print("switch ")
c.expr(stmt.Selector)
c.print(" {\n")
for _, cas := range stmt.Cases {
c.print("case ")
if rangeExpr, ok := cas.Consts[0].(*RangeExpr); ok {
// Making a lot of assumptions here, but this is the only
// way it's used in the ZZT source.
min := rangeExpr.Min.(*ConstExpr).Value.(string)[0]
max := rangeExpr.Max.(*ConstExpr).Value.(string)[0]
for i, b := 0, min; b <= max; i, b = i+1, b+1 {
if i > 0 {
c.print(", ")
}
c.printf("'%c'", b)
}
} else {
c.exprs(cas.Consts)
}
c.print(":\n")
c.stmtNoBraces(cas.Stmt)
}
if stmt.Else != nil {
c.print("default:\n")
c.stmts(stmt.Else)
}
c.print("}")
case *CompoundStmt:
c.print("{\n")
c.stmts(stmt.Stmts)
c.print("}")
case *EmptyStmt:
return
case *ForStmt:
varExpr := &IdentExpr{stmt.Var}
c.printf("for %s = ", stmt.Var)
c.assignRhs(varExpr, stmt.Initial)
if stmt.Down {
c.print("; ")
c.expr(&BinaryExpr{varExpr, GTE, stmt.Final})
c.printf("; %s-- {\n", stmt.Var)
} else {
c.print("; ")
c.expr(&BinaryExpr{varExpr, LTE, stmt.Final})
c.printf("; %s++ {\n", stmt.Var)
}
c.stmtNoBraces(stmt.Stmt)
c.print("}")
case *GotoStmt:
c.printf("goto %s", stmt.Label)
case *IfStmt:
c.print("if ")
c.expr(stmt.Cond)
c.print(" {\n")
c.stmtNoBraces(stmt.Then)
c.print("}")
if stmt.Else != nil {
innerIf, isElseIf := stmt.Else.(*IfStmt)
if isElseIf {
c.print(" else ")
c.stmtNoBraces(innerIf)
} else {
c.print(" else {\n")
c.stmtNoBraces(stmt.Else)
c.print("}")
}
}
case *LabelledStmt:
c.printf("%s:\n", stmt.Label)
c.stmt(stmt.Stmt)
case *ProcStmt:
procStr := strings.ToLower(stmt.Proc.String())
switch procStr {
case "dec":
if len(stmt.Args) != 1 {
panic(fmt.Sprintf("Dec() requires 1 arg, got %d", len(stmt.Args)))
}
c.expr(stmt.Args[0])
c.print("--")
case "exit":
c.print("return")
case "inc":
if len(stmt.Args) != 1 {
panic(fmt.Sprintf("Inc() requires 1 arg, got %d", len(stmt.Args)))
}
c.expr(stmt.Args[0])
c.print("++")
case "str":
if widthExpr, isWidth := stmt.Args[0].(*WidthExpr); isWidth {
c.expr(stmt.Args[1])
c.print(" = StrWidth(")
c.procArg(false, KindInteger, stmt.Args[0])
c.printf(", %d", widthExpr.Width.(*ConstExpr).Value.(int))
c.print(")")
} else {
c.expr(stmt.Args[1])
c.print(" = Str(")
c.procArg(false, KindInteger, stmt.Args[0])
c.print(")")
}
case "val":
c.expr(stmt.Args[1])
c.print(" = ")
spec, _ := c.lookupVarExprType(stmt.Args[1])
targetKind := c.specToKind(spec)
if targetKind != KindInteger {
c.printf("%s(", targetKind)
}
c.print("Val(")
c.procArg(false, KindString, stmt.Args[0])
c.print(", ")
c.procArg(true, KindInteger, stmt.Args[2])
c.print(")")
if targetKind != KindInteger {
c.print(")")
}
default:
if procStr == "delete" {
c.varExpr(stmt.Args[0], false)
c.print(" = ")
}
if procStr == "writeln" {
c.print("WriteLn") // It's sometimes spelled Writeln in the Pascal
} else {
c.varExpr(stmt.Proc, false)
}
spec, _ := c.lookupVarExprType(stmt.Proc)
var params []*ParamGroup
if spec != nil {
params = spec.(*ProcSpec).Params
}
c.print("(")
c.procArgs(params, stmt.Args)
c.print(")")
}
case *RepeatStmt:
c.print("for {\n")
c.stmts(stmt.Stmts)
c.print("if ")
c.expr(stmt.Cond)
c.print(" {\nbreak\n}\n}")
case *WhileStmt:
c.print("for ")
c.expr(stmt.Cond)
c.print(" {\n")
c.stmtNoBraces(stmt.Stmt)
c.print("}")
case *WithStmt:
spec, fieldName := c.lookupVarExprType(stmt.Var)
if spec == nil {
panic(fmt.Sprintf("'with' statement var not found: %s", stmt.Var))
}
spec = c.lookupIdentSpec(spec)
record := spec.(*RecordSpec)
var withName string
if identExpr, isIdent := stmt.Var.(*IdentExpr); isIdent &&
strings.ToLower(fieldName) == strings.ToLower(identExpr.Name) {
withName = identExpr.Name
} else {
withName = c.makeWithName(fieldName)
c.printf("%s := &", withName)
c.varExpr(stmt.Var, false)
c.print("\n")
c.defineWithVar(withName)
}
c.pushWithScope(withName, stmt.Var)
for _, section := range record.Sections {
for _, name := range section.Names {
c.defineVar(name, section.Type)
}
}
c.stmtNoBraces(stmt.Stmt)
c.popScope()
return
default:
panic(fmt.Sprintf("unhandled Stmt: %T", stmt))
}
c.print("\n")
}
func (c *converter) assignRhs(left Expr, right Expr) {
kind := c.exprKind(right)
spec, _ := c.lookupVarExprType(left)
targetKind := c.specToKind(spec)
end := c.startConvertExpr(kind, targetKind, right)
if parenExpr, isParen := right.(*ParenExpr); isParen {
right = parenExpr.Expr
}
c.expr(right)
if end != "" {
c.print(end)
}
}
func (c *converter) startConvertExpr(kind, targetKind Kind, expr Expr) string {
if targetKind == KindByte && kind == KindString {
constExpr, isConst := expr.(*ConstExpr)
if isConst {
str, isStr := constExpr.Value.(string)
if isStr && len(str) == 1 {
return ""
}
}
}
convertKind := c.convertKind(kind, targetKind)
if convertKind == KindString && kind == KindByte {
c.print("string([]byte{")
return "})"
}
if convertKind != KindUnknown {
c.print(convertKind, "(")
return ")"
}
return ""
}
func (c *converter) procArgs(params []*ParamGroup, args []Expr) {
isVars := []bool{}
kinds := []Kind{}
for _, group := range params {
for range group.Names {
isVars = append(isVars, group.IsVar)
spec := &IdentSpec{group.Type}
kinds = append(kinds, c.specToKind(spec))
}
}
for i, arg := range args {
if i > 0 {
c.print(", ")
}
if params != nil {
c.procArg(isVars[i], kinds[i], arg)
} else {
c.procArg(false, KindUnknown, arg)
}
}
}
func (c *converter) convertKind(kind, targetKind Kind) Kind {
if kind != KindUnknown && targetKind != KindUnknown && kind != targetKind {
if kind == KindNumber && targetKind.IsSizedNum() {
return KindUnknown
}
return targetKind
}
return KindUnknown
}
func (c *converter) procArg(targetIsVar bool, targetKind Kind, arg Expr) {
kind := c.exprKind(arg)
end := c.startConvertExpr(kind, targetKind, arg)
switch arg := arg.(type) {
case *IdentExpr:
isVar := c.isVarParam(arg.Name)
switch {
case isVar && targetIsVar:
c.identExpr(arg) // pass pointer straight through
case isVar && !targetIsVar:
c.print("*")
c.identExpr(arg)
case !isVar && targetIsVar:
c.print("&")
c.identExpr(arg)
default: // !isVar && !targetIsVar
c.expr(arg)
}
case *AtExpr, *DotExpr, *IndexExpr, *PointerExpr, *FuncExpr:
if targetIsVar {
c.print("&")
}
c.expr(arg)
case *ConstExpr:
str, isStr := arg.Value.(string)
if isStr && targetKind == KindString {
c.printf("%q", str)
break
}
c.expr(arg)
default:
c.expr(arg)
}
if end != "" {
c.print(end)
}
}
func (c *converter) makeWithName(name string) string {
parts := splitCamel(name)
lastPart := parts[len(parts)-1]
withName := strings.ToLower(strings.TrimSuffix(lastPart, "s"))
if _, spec := c.lookupVarType(withName); spec == nil {
return withName
}
for i := 2; i < 10; i++ {
numName := withName + fmt.Sprint(i)
if _, spec := c.lookupVarType(numName); spec == nil {
return numName
}
}
panic(fmt.Sprintf("too many tries generating 'with' name: %s", withName))
}
func splitCamel(name string) []string {
parts := []string{}
hadCap := false
start := 0
for i, c := range name {
if hadCap && c >= 'a' && c <= 'z' && i > 1 {
parts = append(parts, name[start:i-1])
start = i - 1
}
hadCap = c >= 'A' && c <= 'Z'
}
parts = append(parts, name[start:])
return parts
}
func (c *converter) exprs(exprs []Expr) {
for i, expr := range exprs {
if i > 0 {
c.print(", ")
}
c.expr(expr)
}
}
func isLogical(expr *BinaryExpr) bool {
// This is cheating; should really use types, but this works with most code
_, rightIsConst := expr.Right.(*ConstExpr)
return !rightIsConst && (expr.Op == AND || expr.Op == OR || expr.Op == XOR)
}
func (c *converter) expr(expr Expr) {
switch expr := expr.(type) {
case *BinaryExpr:
if expr.Op == IN {
c.inExpr(expr)
return
}
if isLogical(expr) {
c.expr(expr.Left)
c.printf(" %s ", logicalOperatorStr(expr.Op))
c.expr(expr.Right)
return
}
opStr := operatorStr(expr.Op)
lk := c.exprKind(expr.Left)
rk := c.exprKind(expr.Right)
switch {
case isMathOp(expr.Op) && lk == KindByte && (rk == KindByte || rk == KindNumber):
c.typeConversion(expr.Left, "int16")
c.printf(" %s ", opStr)
if rk == KindByte {
c.typeConversion(expr.Right, "int16")