E0004Type mismatch

Reported by the compiler as an error or warning.

mettle explain E0004

A value of one type was used where a different type is required. Mettle never infers var/local const binding types, so both sides must line up.

Example

var x: int64 = "hello";   // expected 'int64', found 'string'

Fixes

• change the declared type to match the value, or the value to match the type

• for numeric conversions, cast explicitly: (int32)value

Integers are the exception, and only in one direction: a conversion that every value survives happens on its own (int32 -> int64), and one that can change the value needs the cast. Those report M0119 rather than this code, so mettle explain M0119 has the rule.

Type and Field are compile-time reflection values (a TypeRef is a type-table index; a FieldRef is {type_index, field_index}). They have no runtime representation and cannot escape into runtime code. Bind them with const and keep them at compile time.

Related

• E0001Lexical error
• E0002Syntax error
• E0003Semantic error
• E0005Scope error
• E0006I/O error
• E0007Internal compiler error
• M0101Use after free
• M0102Double free