## Types

Gufo has a strict type system and do not allow implicit conversion. For exemple we cannot add a string to an integer.

Gufo’s types are implicitely infered.

### basic types:

– int
– string
– bool : standard true/false boolean
– float
– cmd: this is a special types representing the application of an external program. This is a basic type but owning field attributes.

### Aggregation types:

– list
– set : no order, no duplicated value.
– map : a map is a set of key values binded to values.

list, set and maps can only contains element of same type.

Gufo has ‘struct’ composite types: a struct defines a type with determined and statically typed fields.

## Operators

Gufo has predefined operators: every operator takes two arguments, here denoted by ‘a’ and ‘b’:

a + b : with a and b as int (float) represents the addition of two integers(floats).
a + b : with a and b as string represents the string concatenation operation.

a – b : with a and b as int (float) represents the soustraction of two int (float)

a * b : with a and b as int (float) represents the multiplication of two int (float)

a / b : with a and b as int (float) represents the division of two int (float)

a with b : with a and b a list of elements A represent the list concatenation.

a with b : with a and b a set of elements A represent the set union.

a with b : with a and b a of elements A as key and B as values represent a map merge (a union of the key set). if a key is present in both, the binded value becomes the one from b.

a with b : with a a list of elements A and b an element of type A, return the list a with b added at the head of the list.

a with b : with a a set of elements A and b an element of type A, return the set a union the singleton set containing b.

a wout b : with a and b a set of elements A, return the set a without the elements from b.

a wout b : with a and b a map of elements A as key and B as values, return the map a without the elements from b.

The types also contains standard libraries functions accessible though system modules: for exemple \$Int.toStr is the function taking an integer argument and returning the corresding value as a string.