Codegen Helper

          class 
CodegenContext
 {
  
code
 = ''
  private 
level
 = 0

  
push
(
code
: string) {
    this.
code
 += code
  }

  
newline
(
indent
?: number) {
    this.
push
(`\n${'  '.
repeat
(
indent
 ?? this.
level
)}`)
  }

  
indent
() {
    this.
newline
(++this.
level
)
  }

  
deindent
(
noNewline
 = false) {
    if (
noNewline
) {
      --this.level
    } else {
      this.
newline
(--this.
level
)
    }
  }
}

        

          const 
ctx
 = new 
CodegenContext
()

ctx
.
push
('function sum(a, b){')
ctx
.
indent
()
ctx
.
push
('return a + b')
ctx
.
deindent
()
ctx
.
push
('}')


console
.
log
(
ctx
.
code
)

// "function sum(a, b){
//   return a + b
// }"