Procedural and Object-oriented Programming 1

Unit 5 – Programming Part II

Lists · Tuples · for loops · and a real Rexx parser

Lists

Sequences

Lists

Array (sequence) of elements — ordered and mutable
[] creates a list; access with an index (0-based)
Insert with append() and insert()

colors = ['blue', 'red', 'green']
colors[1]          # => 'red'
colors.append('orange')
colors.insert(1, 'yellow')

Sequences

Lists vs. Tuples

List — mutable

Defined with []
Elements can change
append, insert, remove

colors = ['blue', 'red']
colors.append('green')

Tuple — immutable

Defined with ()
Elements are fixed
Less overhead than a list

base = ('red', 'blue')
base[0]  # => 'red'

for loops

Iteration · time-driven build

Example of a for loop

This slide builds itself on a timer — keys override it at any moment

lectures = ['Maths', 'English', 'Computer Science']

for lecture in lectures:
    print(f'I love {lecture}')

Output:

I love Maths
I love English
I love Computer Science

The Rexx angle

The Rexx Highlighter

What a real parser can see

/**
 * This is a doc-comment. The first statement, up to the first period,
 * is the summary, and the rest is the description.
 *
 * @param name Description
 */
::Method open Package Protected         -- Bold, underline, italic
  Expose x pos stem.

  Use Strict Arg name

  a   = 12.34e-56 + " -98.76e+123 "     -- Highlighting of numbers
  len = Length( Stem.12.2a.x.y )        -- A built-in function call
  pos = Pos( "S", "String" )      -- An internal function call
  Call External pos, len, .True         -- An external function call
  .environment~test.2.x = test.2.x      -- Method call, compound variable

  Exit "नमस्ते"G,  "P ≝ 𝔐",  "🦞🍐"     -- Unicode strings

Get in touch

Contact

Prof. Rony G. Flatscher

Institute for Society and Information Systems

Email rony.flatscher@wu.ac.at

Web wu.ac.at/en/isis

Office Welthandelsplatz 1, D2-C, A-1020 Vienna

Josep Maria Blasco

Rexx Parser · EPBCN

Email josep.maria.blasco@epbcn.com

Web rexx.epbcn.com/rexx-parser

Office Barcelona

section · code style · ⓘ