repogen/internal/codegen/function.go
2023-05-24 14:04:29 +03:00

73 lines
1.4 KiB
Go

package codegen
import (
"bytes"
"fmt"
"strings"
"text/template"
"git.kmsign.ru/royalcat/repogen/internal/code"
)
const functionTemplate = `
func {{.Name}}({{.GenParams}}){{.GenReturns}} {
{{.Body.Code}}
}
`
// FunctionBuilder is an implementer of a function.
type FunctionBuilder struct {
Name string
Params []code.Param
Returns []code.Type
Body FunctionBody
}
// Impl writes function declatation code to the buffer.
func (fb FunctionBuilder) Impl(buffer *bytes.Buffer) error {
tmpl, err := template.New("function").Parse(functionTemplate)
if err != nil {
return err
}
// writing to a buffer should not cause errors.
_ = tmpl.Execute(buffer, fb)
return nil
}
func (fb FunctionBuilder) GenParams() string {
return generateParams(fb.Params)
}
func (fb FunctionBuilder) GenReturns() string {
return generateReturns(fb.Returns)
}
func generateParams(params []code.Param) string {
var paramList []string
for _, param := range params {
paramList = append(
paramList,
fmt.Sprintf("%s %s", param.Name, param.Type.Code()),
)
}
return strings.Join(paramList, ", ")
}
func generateReturns(returns []code.Type) string {
if len(returns) == 0 {
return ""
}
if len(returns) == 1 {
return " " + returns[0].Code()
}
var returnList []string
for _, ret := range returns {
returnList = append(returnList, ret.Code())
}
return fmt.Sprintf(" (%s)", strings.Join(returnList, ", "))
}