Mirror of forum.nim-lang.org

7169 :: How to evaluate string in Nim's VM at runtime?

• r3c (orginal) [2020-11-27T23:29:46+01:00] view original

  Hi, I'm writing custom ast builder, and was thinking instead of dumping the ast to file, use nim for runtime evaluation

  For ex. lets say we have

  echo(1 < 2) # true
  Run

  what I want is:

  echo evalDsl("1 < 2") # should output true
  Run

  Is this possible?

---

• timothee (orginal) [2020-11-28T01:00:31+01:00] view original

  tests/compilerapi/tcompilerapi.nim

---

• r3c (orginal) [2020-11-28T14:33:14+01:00] view original

  Thanks, i think tcompilerapi.nim will do.

  But if one wants to create html templating engine is this the right direction?

  
  {if user.loggedIn}
          <button>
                  Log out
          </button>
  {/if}
  Run

---

• Araq (orginal) [2020-11-28T15:56:14+01:00] view original

  No, use Nim's source code filters. Or Karax or anything comparable. When you don't precompile the templates ("but I must be able to change the templates at runtime!" -- "no, you don't".) you're in a world of marshalling where the data first needs to be converted into JSON like formats just so that your template engine can handle it. It's a bad idea.

---