WriteStream in Smalltalk

Build a string without repeated concatenation.

"A WriteStream builds a string without repeated concatenation."
| report |
report := WriteStream on: String new.
report
    nextPutAll: 'DAILY DOCKET';
    cr;
    nextPutAll: '3 jobs, ';
    print: 545;
    nextPutAll: ' sheets'.

Transcript show: report contents; cr.

"streamContents: wraps the same pattern in one expression."
Transcript show: (String streamContents: [:s |
    #('set' 'ink' 'pull') do: [:step | s nextPutAll: step]
        separatedBy: [s nextPutAll: ' / ']]); cr.

How it works

1. WriteStream on: String new opens the builder.
2. nextPutAll: appends; print: formats numbers in.
3. streamContents: wraps the pattern in one expression.

Keywords and builtins used here

• String
• Transcript
• WriteStream
• contents
• cr
• new
• report

The run, in numbers

Lines

16

Characters to type

454

Tokens

78

Three-star pace

55 tpm

At the three-star pace of 55 tokens a minute, this run takes about 85 seconds.

Type this snippet

Step 1 of 2 in Streams, step 24 of 31 in Language basics.

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