Module 6 Flash Cards

Front 1

Scope Of Binding

Back 1

The later bindings in that let-expression and the “body” of the let-expression (the e)

Front 2

ML let expression (syntax, semantics, type checking)

Back 2

Syntax:

let b1 b2 ... bn in e end

where each bi is a binding and e is an expression.

Semantics: much like the semantics of the top-level bindings in our ML program

Type Checking:we can use all the earlier bindings for the later ones, and we can use them all for e

Front 3

ML options:

Back 3

Option value has either 0 or 1 thing:NONE is an option value “carrying nothing” whereas SOME e evaluates e to a value v and becomes the option carrying the one value v. The type of NONE is ’a option and the type of SOME e is t option if e has type t

Front 4

andalso (syntax, semantics, type checking)

Back 4

Syntax:e1 andalso e2

Type Checking: e1 and e2 must both have type bool and the entire expression also has type bool

Semantics:he result is true if e1 and e2 evaluate to true

Front 5

orelse (syntax, semantics, type checking)

Back 5

Syntax : e1 orelse e2

Semantics: It evaluates e2 only if e1 evaluates to false ,he result is true if e1 or e2 evaluates to true.

Type Checking : e1 and e2 must both have type bool and the entire expression also has type bool.

Front 6

immutable data

Back 6

data that can not be mutated

Front 7

aliasing

Back 7

Returning a copy of previously defined data

Front 8

Idioms

Back 8

common approaches to using the language features to express computations