Glossary

the inputs to a function; expressions for arguments follow the name of a function

a type of data with two values: true and false

a function that creates instances of a data structure

a statement of the name, domain, and range of a function

errors where the code makes sense, but uses a function with the wrong number or type of arguments

a datatype which packages several datatypes as fields

a way of classifying values, such as: Number, String, Image, Boolean, or any user-defined data structure

the left-most text box in the Editor where definitions for values and functions are written

a sequence of steps that helps people document, test, and write functions

the type or set of inputs that a function expects

software in which you can write and evaluate code

information from the computer about errors in code

something that happens outside of a running program, which the program can respond to

shows the use of a function on specific inputs and the computation the function should perform on those inputs

a part of a data structure that has a name and holds a single value of a specified datatype

a mathematical object that consumes inputs and produces an output

code that names a function, lists its variables, and states the expression to compute when the function is used

Connects an event (like a tick or keypress) and a function within a reactor

a small function that handles a specific part of another computation, and gets called from other functions

the side opposite the 90-degree angle in a right triangle

a type of data for pictures

a specific, packaged value of a data structure that contains other values in its fields

the right-most text box in the Editor, where expressions are entered to evaluate

how we refer to a function or value defined in a language (examples: +, *, star, circle)

a symbol that manipulates two Numbers and produces a result

a function that computes different expressions based on its input

a concise, detailed description of what a function does with its inputs

the type or set of outputs that a function produces

a value that contains a current state, and functions for updating, drawing, and interacting with that state

the process of changing the style or structure of a program’s code, without changing the program’s behavior

the value of a changing system at any point in time (i.e. a stoplight can be in the 'red', 'yellow' or 'green' state). In Pyret, the state of a Reactor is it’s current value.

the set of rules that defines a language, whether it be spoken, written, or programmed.

errors where the computer cannot make sense of the code (e.g. - missing commas, parentheses, unclosed strings)

a specific piece of data, like 5 or "hello"

a letter or symbol that stands in for a value or expression