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Lesson 02 — Control Flow

if / else_if / else / end_if

global_variable = age
age = 20

if age >= 18
    say "You are an adult."
else
    say "You are a minor."
end_if

else is optional, and else_if lets you chain extra conditions without nested fallback blocks. Conditions support ==, !=, <, >, <=, >=, and logical operators and, or, not.

if age >= 18 and age < 65
    say "Working age."
end_if

if name == "" or name == "unknown"
    say "No name provided."
end_if

if score >= 90
    say "Grade A"
else_if score >= 80
    say "Grade B"
else
    say "Keep going"
end_if

Nested if

if score > 50
    if score > 90
        say "Excellent!"
    else
        say "Passed."
    end_if
else
    say "Failed."
end_if

else_if in file loops

else_if also works inside for_each blocks when you want a single classification chain:

for_each file_in here
    if_ends_with ".jpg"
        say "It's an image"
    else_if file_ext == ".mp4"
        say "It's a video"
    else
        say "Unknown file type"
    end_if
end_for

repeat

Runs a block a fixed number of times.

repeat 5
    say "Hello!"
end_repeat

loop

Runs a block a fixed number of times, or forever.

loop 3
    say "Looping..."
end_loop

loop 3 as i
    say 'Iteration {i}'
end_loop

loop forever
    say "This runs until Ctrl+C"
end_loop

loop forever as i
    say 'Heartbeat #{i}'
end_loop

break and continue

break exits the current loop. continue skips to the next iteration.

global_variable = i
i = 0

loop forever
    i = i + 1
    if i == 5
        break
    end_if
    say 'i = {i}'
end_loop

continue is particularly useful inside for_each to skip certain files:

for_each file_in here
    if_ends_with ".do"
        continue        # skip .do files, process everything else
    end_if
    say 'Processing: {file_name}'
end_for

try / catch / end_try

Catches errors so your script can handle them gracefully.

try
    download "https://example.com/file.zip" to "file.zip"
catch NetworkError
    say "Download failed — check your connection."
end_try

Available error types to catch:

Type Raised by
NetworkError download, http_get, ping, etc.
FileError copy, move, delete, file reads
ProcessError run, execute, kill
DataError json_read, csv_read, etc.
(no type) Catches any error 
try
    delete "important.txt"
catch FileError
    warn "Could not delete the file."
catch
    error "Something unexpected happened."
end_try