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module util::Validator

rascal-0.40.16

Generic validator function that can convert values of the node type to instances of abstract data type constructors.

Usage​

import util::Validator;

Dependencies​

import Type;
import Node;
import List;
import Exception;
import IO;

Description​

The intended use-case is to read structured data externally, say an XML or JSON or YAML file, as generic node values and then to use the validate function to map the untyped representation to a typed representation, if it can be validated accordingly.

data RuntimeException​

data RuntimeException  
     = invalid(str \type, value v, list[value] path=[])
     ;

data RuntimeException​

data RuntimeException  
     = none()
     ;

function validate​

The general and simple validation case is when a value's run-time type already matches the expected static type.

&T validate(type[&T] expected, value v, list[value] path=[], bool relaxed=false)

function validate​

To validate nodes we can try whether or not it can be matched to a constructor of a defined data type with the same name and (resp. validating) children.

&T validate(type[&T] expected, node v, list[value] path = [], bool relaxed=false)

function validate​

If a (sub)value can not be validated we report the expected type, the not-matching value and the path that led us there.

default &T validate(type[&T] expected, value v, list[value] path=[], bool relaxed=false)

Tests

test simpleInt​

test bool simpleInt() {
    value x = 1;
  
    return int _ := validate(#int, x);
}

test defaultNode​

test bool defaultNode() {
    value x = "hello"();
    
    return node _ := validate(#node, x);
}

test adtTest​

test bool adtTest() {
   value x = "invalid"("XXX", [[[]]],path=[1,0,0]);
   
   return RuntimeException _ := validate(#RuntimeException, x);
}

test adtRelaxedTest​

test bool adtRelaxedTest() {
   value x = "object"("XXX", [[[]]],path=[1,0,0]);
   
   return RuntimeException _ := validate(#RuntimeException, x, relaxed=true);
}

test adtTestFail​

test bool adtTestFail() {
  value x = "invali"("XXX", [[[]]],path=[1,0,0]);
  
  try {
      validate(#RuntimeException, x);
      return false;
  }
  catch invalid(_,_) : 
      return true;
  
}

test adtTestFailNested​

test bool adtTestFailNested() {
  value x = "invalid"(2, [[[]]],path=[1,0,0]);
  
  try {
      validate(#RuntimeException, x);
      return false;
  }
  catch invalid(_,_) : 
      return true;
  
}

test adtTestFailKeyword​

test bool adtTestFailKeyword() {
  value x = "invalid"("hello", [[[]]],path="[1,0,0]");
  
  try {
      validate(#RuntimeException, x);
      return false;
  }
  catch invalid(_,_) : 
      return true;
  
}