DSL Reference - Animation DSL Language Specification~

# This is a full-line comment
# strip length 30  # This is an inline comment (TEMPORARILY DISABLED)
color bordeaux = 0x6F2C4F  # This is an inline comment

# Strip configuration is handled automatically
# strip length 60  # TEMPORARILY DISABLED

# Color definitions
color bordeaux = 0x6F2C4F
color majorelle = 0x6050DC

# Animation definitions
animation pulse_bordeaux = pulsating_animation(color=bordeaux, period=2s)

# Property assignments
pulse_red.priority = 10

# Sequences
sequence demo {
  play pulse_bordeaux for 5s
  wait 1s
}

# Execution
run demo

42          # Integer
3.14        # Floating point
-5          # Negative number

500ms       # Milliseconds (stays 500)
2s          # Seconds (converted to 2000ms)
1m          # Minutes (converted to 60000ms)
1h          # Hours (converted to 3600000ms)

0%          # 0 percent (converted to 0)
50%         # 50 percent (converted to 128)
100%        # 100 percent (converted to 255)
120%        # 120 percent (converted to 306)

0xFF0000    # Red (RGB format)
0x80FF0000  # Semi-transparent red (ARGB format)

red         # Predefined color name
blue        # Predefined color name
transparent # Transparent color

"hello"     # Double-quoted string
'world'     # Single-quoted string

my_color        # Valid identifier
_private_var    # Valid identifier
Color123        # Valid identifier

# strip length 60     # TEMPORARILY DISABLED

set brightness = 200        # Static integer value
set cycle_time = 5s         # Static time value (converted to 5000ms)
set opacity_level = 80%     # Static percentage (converted to 204)

# Value providers for dynamic values
set brightness_osc = smooth(min_value=50, max_value=255, period=3s)
set position_sweep = triangle(min_value=0, max_value=29, period=5s)

# Computed values using strip length
set strip_len = strip_length()  # Get current strip length

import user_functions       # Import user-defined functions
import my_custom_module     # Import custom animation libraries
import math                 # Import standard Berry modules
import string               # Import utility modules

# Import user functions for computed parameters
import user_functions

animation dynamic = solid(color=blue)
dynamic.opacity = my_custom_function()

# Import custom animation libraries
import fire_effects

animation campfire = fire_effects.create_fire(intensity=200)

# DSL Code
import user_functions

# Transpiles to Berry Code
import "user_functions"

berry """
import math
var custom_value = math.pi * 2
print("Custom calculation:", custom_value)
"""

berry '''
# Alternative syntax with single quotes
def helper_function(x)
  return x * 1.5
end
'''

animation pulse = pulsating_animation(color=red, period=2s)

berry """
# Modify animation using Berry code
pulse_.opacity = 200
pulse_.priority = 10
print("Animation configured")
"""

run pulse

# Define the function in a berry block
berry """
def rand_meter(time_ms, self)
  import math
  var r = math.rand() % 101
  return r
end

def breathing_effect(base_value, amplitude)
  import math
  var time_factor = (tasmota.millis() / 1000) % 4  # 4-second cycle
  var breath = math.sin(time_factor * math.pi / 2)
  return int(base_value + breath * amplitude)
end
"""

# Declare functions as external so DSL knows about them
extern function rand_meter
extern function breathing_effect

# Now they can be used in DSL expressions
animation back_pattern = palette_meter_animation(value_func = rand_meter)
animation breathing_light = solid(color=blue)
breathing_light.opacity = breathing_effect

run back_pattern

berry """
def my_external_func(engine, param1, param2)
  # engine is automatically provided by DSL
  # param1, param2 are user-provided parameters
  return computed_value
end
"""

extern function my_external_func

# Usage in DSL (engine parameter is automatic)
animation test = solid(color=red)
test.opacity = my_external_func  # Called as my_external_func(engine)

# Static colors
color bordeaux = 0x6F2C4F           # Static hex color
color majorelle = 0x6050DC          # Static hex color
color semi_red = 0x80FF0000         # Static color with alpha channel
color my_white = white              # Reference to predefined color

# Color providers for dynamic colors
color rainbow_cycle = color_cycle(
  colors=bytes("FFFF0000" "FF00FF00" "FF0000FF")
  period=5s
)
color breathing_red = breathe_color(
  base_color=red
  min_brightness=5%
  max_brightness=100%
  duration=3s
  curve_factor=2
)
color pulsing_blue = pulsating_color(
  base_color=blue
  min_brightness=20%
  max_brightness=80%
  duration=1s
)

# Traditional syntax with commas
palette fire_colors = [
  (0, 0x000000)      # Position 0: Black
  (128, 0xFF0000)    # Position 128: Red
  (255, 0xFFFF00)    # Position 255: Yellow
]

# New syntax without commas (when entries are on separate lines)
palette ocean_palette = [
  (0, navy)          # Using named colors
  (128, cyan)
  (255, green)
]

# Mixed syntax also works
palette matrix_greens = [
  (0, 0x000000), (64, 0x003300)    # Multiple entries on one line
  (128, 0x006600)                  # Single entry on separate line
  (192, 0x00AA00)
  (255, 0x00FF00)
]

palette timed_colors = [
  (10, 0xFF0000)     # Red for 10 ticks
  (20, 0x00FF00)     # Green for 20 ticks  
  (15, 0x0000FF)     # Blue for 15 ticks
]

palette valid_colors = [
  (0, 0xFF0000)      # Hex colors
  (128, red)         # Predefined color names
  (255, blue)        # More predefined colors
]

color custom_red = 0xFF0000
palette invalid_colors = [
  (0, custom_red)    # ERROR: Custom colors not allowed
  (128, my_color)    # ERROR: Undefined color
]

# Define a user function that creates dynamic palettes
def create_custom_palette(engine, base_color, intensity)
  # Create palette with custom logic
  var palette_data = create_dynamic_palette_bytes(base_color, intensity)
  return palette_data
end

# Register for DSL use
animation.register_user_function("custom_palette", create_custom_palette)

# Use in DSL
animation dynamic_anim = rich_palette(
  colors=custom_palette(0xFF0000, 200)
  period=3s
)

animation red_solid = solid(color=red)

animation pulse_effect = pulsating_animation(
  color=blue
  period=2s
)

animation comet_trail = comet_animation(
  color=white
  tail_length=10
  speed=1500
  direction=1
)

animation pulse_red = pulsating_animation(color=red, period=2s)

# Set properties
pulse_red.priority = 10
pulse_red.opacity = 200
pulse_red.position = 15

# Dynamic properties using value providers
pulse_red.position = triangle(min_value=0, max_value=29, period=5s)
pulse_red.opacity = smooth(min_value=100, max_value=255, period=2s)

# Computed properties using arithmetic expressions
set strip_len = strip_length()
pulse_red.position = strip_len / 2      # Center position
pulse_red.opacity = strip_len * 4       # Scale with strip size

# Animation opacity (using another animation as opacity mask)
animation opacity_mask = pulsating_animation(period=2s)
pulse_red.opacity = opacity_mask        # Dynamic opacity from animation

# ✅ RECOMMENDED: Single value provider assignment
set strip_len = strip_length()

# ✅ RECOMMENDED: Computation with existing values
set strip_len2 = (strip_len + 1) / 2

# Use computed values in animation parameters
animation stream1 = comet_animation(
  color=red
  tail_length=strip_len / 4    # Computed: quarter of strip length
  speed=1.5
  priority=10
)

# ❌ DANGEROUS: Function creation in computed expression
# This would create a new strip_length() instance at each evaluation
set strip_len3 = (strip_length() + 1) / 2

# ❌ ERROR: Transpiler will reject this with:
# "Function 'strip_length()' cannot be used in computed expressions.
#  This creates a new instance at each evaluation."

# ✅ CORRECT: Separate the value provider creation from computation
set strip_len = strip_length()      # Single value provider
set strip_len3 = (strip_len + 1) / 2  # Computation with existing value

# Complex expressions with multiple operations
set base_speed = 2.0
animation stream2 = comet_animation(
  color=blue
  tail_length=strip_len / 8 + 2    # Computed: eighth of strip + 2
  speed=base_speed * 1.5           # Computed: base speed × 1.5
)

# Computed values in property assignments
stream1.position = strip_len / 2     # Center of strip
stream2.opacity = strip_len * 4      # Scale opacity with strip size

# Using mathematical functions in computed values
animation pulse = pulsating_animation(
  color=red
  period=2s
)
pulse.opacity = abs(sine(strip_len) * 128 + 127)    # Sine wave opacity
pulse.position = max(0, min(strip_len - 1, round(strip_len / 2)))  # Clamped center position

# Basic math functions
set strip_len = strip_length()
animation test = pulsating_animation(color=red, period=2s)

# Absolute value for ensuring positive results
test.opacity = abs(strip_len - 200)

# Min/max for clamping values
test.position = max(0, min(strip_len - 1, 15))  # Clamp position to valid range

# Rounding for integer positions
test.position = round(strip_len / 2.5)

# Square root for non-linear scaling
test.brightness = sqrt(strip_len * 4)  # Non-linear brightness based on strip size

# Scaling values between ranges
test.opacity = scale(strip_len, 10, 60, 50, 255)  # Scale strip length to opacity range

# Trigonometric functions for wave patterns
set angle = 128  # 180 degrees in 0-255 range
test.opacity = sin(angle) + 128      # Mathematical sine function (not oscillator)
test.brightness = cos(angle) + 128  # Mathematical cosine function (not oscillator)

# Complex expressions combining multiple functions
test.position = max(0, round(abs(sin(strip_len * 2)) * (strip_len - 1) / 255))
test.opacity = min(255, max(50, scale(sqrt(strip_len), 0, 16, 100, 255)))

# Simple user function in computed parameter
animation base = solid(color=blue)
base.opacity = rand_demo()

# User functions mixed with math operations
animation dynamic = solid(
  color=purple
  opacity=max(50, min(255, rand_demo() + 100))
)

# Simple user function
animation.opacity = rand_demo()

# User function with math operations
animation.opacity = max(100, rand_demo())

# User function in arithmetic expressions
animation.opacity = abs(rand_demo() - 128) + 64

sequence demo {
  play red_animation for 3s
  wait 1s
  play blue_animation for 2s

  repeat 3 times {
    play flash_effect for 200ms
    wait 300ms
  }

  play final_animation
}

# Option 1: Traditional syntax with repeat sub-sequence
sequence cylon_eye {
  repeat forever {
    play red_eye for 3s
    red_eye.pos = triangle_val
    play red_eye for 3s
    red_eye.pos = cosine_val
    eye_color.next = 1
  }
}

# Option 2: Alternative syntax - sequence with repeat modifier
sequence cylon_eye repeat forever {
  play red_eye for 3s
  red_eye.pos = triangle_val
  play red_eye for 3s
  red_eye.pos = cosine_val
  eye_color.next = 1
}

# Option 3: Parametric repeat count
sequence rainbow_cycle repeat palette.size times {
  play animation for 1s
  colors.next = 1
}

play animation_name                 # Play indefinitely
play animation_name for 5s          # Play for specific duration
play animation_name for duration_var # Play for variable duration

wait 1s                            # Wait for 1 second
wait 500ms                         # Wait for 500 milliseconds
wait duration_var                  # Wait for variable duration

play animation for 5s              # 5 seconds
play animation for 2000ms          # 2000 milliseconds
play animation for 1m              # 1 minute

set short_time = 2s
set long_time = 10s

sequence demo {
  play animation for short_time     # Use variable duration
  wait long_time                    # Variables work in wait too
}

set dynamic_duration = triangle(min_value=1000, max_value=5000, period=10s)

sequence demo {
  play animation for dynamic_duration  # Duration changes over time
}

# Cylon eye with variable duration
set eye_duration = 5s

sequence cylon_eye forever {
  play red_eye for eye_duration     # Use variable for consistent timing
  red_eye.pos = triangle_val
  play red_eye for eye_duration     # Same duration for both phases
  red_eye.pos = cosine_val
  eye_color.next = 1
}

repeat 3 times {                   # Repeat exactly 3 times
  play animation for 1s
  wait 500ms
}

repeat forever {                   # Repeat indefinitely until parent sequence stops
  play animation for 1s
  wait 500ms
}

repeat col1.palette_size times {   # Parametric repeat count using property access
  play animation for 1s
  col1.next = 1
}

sequence demo {
  play red_eye for 3s
  red_eye.pos = triangle_val        # Change position to triangle oscillator
  play red_eye for 3s
  red_eye.pos = cosine_val          # Change position to cosine oscillator
  eye_color.next = 1                # Advance color cycle to next color
}

sequence dynamic_show {
  play pulse_anim for 2s
  pulse_anim.opacity = 128          # Set static opacity
  play pulse_anim for 2s
  pulse_anim.opacity = brightness   # Use value provider
  play pulse_anim for 2s
  pulse_anim.color = next_color     # Change color provider
  play pulse_anim for 2s
}

# Assignments work in repeat blocks too
sequence cylon_eye {
  repeat 3 times {
    play red_eye for 1s
    red_eye.pos = triangle_val      # Change oscillator pattern
    play red_eye for 1s
    red_eye.pos = cosine_val        # Change back
    eye_color.next = 1              # Advance color
  }
}

if condition {                     # Execute if condition is true (non-zero)
  play animation for 1s
  wait 500ms
}

# Static condition
sequence demo {
  if true {
    play animation for 1s
  }
}

# Template parameter condition
template animation configurable {
  param enable_effect type bool default true

  color my_red = 0xFF0000
  animation solid_red = solid(color=my_red)

  sequence main repeat forever {
    if enable_effect {
      play solid_red for 1s
    }
  }

  run main
}

# Variable condition
set flag = true
sequence conditional {
  if flag {
    play animation for 2s
  }
}

# Bidirectional animation with flags
template animation shutter_bidir {
  param ascending type bool default true
  param descending type bool default true

  sequence shutter_seq repeat forever {
    if ascending {
      play shutter_lr for 2s
    }
    if descending {
      play shutter_rl for 2s
    }
  }

  run shutter_seq
}

restart value_provider_name        # Restart value provider from beginning
restart animation_name             # Restart animation from beginning

# Restart oscillators for synchronized movement
sequence sync_demo {
  play wave_anim for 3s
  restart position_osc            # Restart oscillator time origin
  play wave_anim for 3s
}

# Restart animations for clean transitions
sequence clean_transitions {
  play comet_anim for 5s
  restart comet_anim              # Restart from beginning position
  play comet_anim for 5s
}

template animation shutter_effect {
  param colors type palette nillable true
  param duration type time min 0 max 3600 default 5 nillable false

  set strip_len = strip_length()
  set shutter_size = sawtooth(min_value = 0, max_value = strip_len, duration = duration)

  color col = color_cycle(colors=colors, period=0)

  animation shutter = beacon_animation(
    color = col
    pos = strip_len / 2
    beacon_size = shutter_size
    priority = 5
  )

  sequence seq repeat forever {
    restart shutter_size
    play shutter for duration
    col.next = 1
  }

  run seq
}

# Use the template animation
palette rainbow = [red, orange, yellow, green, blue, indigo, white]
animation my_shutter = shutter_effect(colors=rainbow, duration=2s)
run my_shutter

class shutter_effect_animation : animation.engine_proxy
  static var PARAMS = animation.enc_params({
    "colors": {"type": "palette"},
    "duration": {"type": "time", "min": 0, "max": 3600, "default": 5}
  })

  def init(engine)
    super(self).init(engine)
    # Generated code with self.colors and self.duration references
    self.add(seq_)
  end
end

# These parameters are implicitly available in all template animations:
param id type string default "animation"
param priority type int default 10
param duration type int default 0
param loop type bool default false
param opacity type int default 255
param color type int default 0
param is_running type bool default false

template animation fade_effect {
  param colors type palette

  # 'duration' is an implicit parameter - no need to declare it
  set oscillator = sawtooth(min_value=0, max_value=255, duration=duration)

  color col = color_cycle(colors=colors, period=0)
  animation test = solid(color=col)

  # 'opacity' is also implicit
  test.opacity = oscillator

  run test
}

# When instantiating, you can set implicit parameters
animation my_fade = fade_effect(colors=rainbow)
my_fade.duration = 5000  # Set the implicit duration parameter
my_fade.opacity = 200    # Set the implicit opacity parameter

template bad_example {
  param color type color      # ❌ Error: conflicts with built-in color
  param animation type number # ❌ Error: conflicts with reserved keyword  
  param my_param type color
  param my_param type number  # ❌ Error: duplicate parameter name
}

template type_example {
  param my_color type invalid_type  # ❌ Error: invalid type annotation
  param valid_color type color      # ✅ Valid type annotation
}

template unused_example {
  param used_color type color
  param unused_param type number    # ⚠️ Warning: parameter never used

  animation test = solid(color=used_color)
  run test
}

run animation_name      # Run an animation
run sequence_name       # Run a sequence

log("Debug message")           # Log message at level 3
log("Animation started")       # Useful for debugging sequences
log("Color changed to red")    # Track animation state changes

+       # Addition
-       # Subtraction (also unary minus)
*       # Multiplication
/       # Division
%       # Modulo

==      # Equal to
!=      # Not equal to
<       # Less than
<=      # Less than or equal
>       # Greater than
>=      # Greater than or equal

&&      # Logical AND
||      # Logical OR
!       # Logical NOT

=       # Simple assignment

# Single line (commas required)
function_name(param1=value1, param2=value2)

# Multi-line (commas optional when parameters are on separate lines)
function_name(
  param1=value1
  param2=value2
  param3=value3
)

# Mixed syntax (both commas and newlines work)
function_name(
  param1=value1, param2=value2
  param3=value3
)

# Traditional single-line syntax
solid(color=red)
pulsating_animation(color=blue, period=2s)

# New multi-line syntax (no commas needed)
pulsating_animation(
  color=blue
  period=2s
  brightness=255
)

# Mixed syntax
comet_animation(
  color=stream_pattern, tail_length=15
  speed=1.5s
  priority=10
)

pulsating_animation(
  color=solid(color=red)
  period=smooth(
    min_value=1000
    max_value=3000
    period=10s
  )
)

animation wave = pulsating_animation(
  color=blue
  period=2s
)

# Mathematical functions in property assignments
wave.opacity = abs(sine(strip_length()) - 128)           # Sine wave opacity
wave.position = max(0, min(strip_length() - 1, 15))      # Clamped position
wave.brightness = round(sqrt(strip_length()) * 4)        # Non-linear scaling

# Direct oscillator usage
triangle(min_value=0, max_value=255, period=2s)    # Triangle wave
smooth(min_value=50, max_value=200, period=3s)     # Smooth cosine
cosine_osc(min_value=3, max_value=1, period=5s)    # Cosine wave (alias for smooth)
sine_osc(min_value=0, max_value=255, period=2s)    # Pure sine wave
linear(min_value=0, max_value=100, period=1s)      # Linear progression
ramp(min_value=0, max_value=255, period=2s)        # Sawtooth wave
square(min_value=0, max_value=255, period=1s)      # Square wave
ease_in(min_value=0, max_value=255, period=2s)     # Quadratic ease-in
ease_out(min_value=0, max_value=255, period=2s)    # Quadratic ease-out
elastic(min_value=0, max_value=255, period=2s)     # Elastic spring effect
bounce(min_value=0, max_value=255, period=2s)      # Bouncing ball effect

# Value providers can be assigned to variables
set brightness_oscillator = smooth(min_value=50, max_value=255, period=3s)
set position_sweep = triangle(min_value=0, max_value=29, period=5s)
set elastic_movement = elastic(min_value=0, max_value=30, period=4s)
set sine_wave = sine_osc(min_value=0, max_value=255, period=2s)
set cosine_wave = cosine_osc(min_value=50, max_value=200, period=3s)
set strip_len = strip_length()  # Get the current strip length

# Invalid: Redefining predefined color
color red = 0x800000                # Error: Cannot redefine 'red'

# Invalid: Unknown parameter in constructor
animation bad = pulsating_animation(invalid_param=123)  # Error: Unknown parameter

# Invalid: Unknown parameter in property assignment
animation pulse = pulsating_animation(color=red, period=2s)
pulse.wrong_arg = 15                # Error: Parameter 'wrong_arg' not valid for PulseAnimation

# Invalid: Undefined reference in color definition
animation ref = solid(color=undefined_color)        # Error: Undefined reference

# Invalid: Undefined reference in run statement
run undefined_animation             # Error: Undefined reference 'undefined_animation' in run

# Invalid: Undefined reference in sequence
sequence demo {
  play undefined_animation for 5s   # Error: Undefined reference 'undefined_animation' in sequence play
}

# Valid alternatives
color my_red = 0x800000             # OK: Different name
animation good = pulsating_animation(color=red, period=2s)  # OK: Valid parameters
good.priority = 10                  # OK: Valid parameter assignment

(* Animation DSL Grammar *)

program = { statement } ;

statement = import_stmt
          | config_stmt 
          | definition 
          | property_assignment 
          | sequence 
          | template_def
          | external_stmt
          | execution_stmt ;

(* Import and Configuration *)
import_stmt = "import" identifier ;
config_stmt = variable_assignment ;
external_stmt = "extern" "function" identifier ;
(* strip_config = "strip" "length" number ; -- TEMPORARILY DISABLED *)
variable_assignment = "set" identifier "=" expression ;

(* Definitions *)
definition = color_def | palette_def | animation_def | template_animation_def ;
color_def = "color" identifier "=" color_expression ;
palette_def = "palette" identifier "=" palette_array ;
animation_def = "animation" identifier "=" animation_expression ;
template_animation_def = "template" "animation" identifier "{" template_body "}" ;

(* Property Assignments *)
property_assignment = identifier "." identifier "=" expression ;

(* Sequences *)
sequence = "sequence" identifier [ "repeat" ( expression "times" | "forever" ) ] "{" sequence_body "}" ;
sequence_body = { sequence_statement } ;
sequence_statement = play_stmt | wait_stmt | repeat_stmt | if_stmt | sequence_assignment | restart_stmt ;

play_stmt = "play" identifier [ "for" time_expression ] ;
wait_stmt = "wait" time_expression ;
repeat_stmt = "repeat" ( expression "times" | "forever" ) "{" sequence_body "}" ;
if_stmt = "if" expression "{" sequence_body "}" ;
sequence_assignment = identifier "." identifier "=" expression ;
restart_stmt = "restart" identifier ;

(* Template Animations *)
template_animation_def = "template" "animation" identifier "{" template_body "}" ;
template_body = { template_statement } ;
template_statement = param_decl | color_def | palette_def | animation_def | property_assignment | sequence_def | execution_stmt ;
param_decl = "param" identifier [ "type" identifier ] [ constraint_list ] ;
constraint_list = ( "min" number | "max" number | "default" expression | "nillable" boolean ) { constraint_list } ;

(* Execution *)
execution_stmt = "run" identifier ;

(* Expressions *)
expression = logical_or_expr ;
logical_or_expr = logical_and_expr { "||" logical_and_expr } ;
logical_and_expr = equality_expr { "&&" equality_expr } ;
equality_expr = relational_expr { ( "==" | "!=" ) relational_expr } ;
relational_expr = additive_expr { ( "<" | "<=" | ">" | ">=" ) additive_expr } ;
additive_expr = multiplicative_expr { ( "+" | "-" ) multiplicative_expr } ;
multiplicative_expr = unary_expr { ( "*" | "/" | "%" ) unary_expr } ;
unary_expr = ( "!" | "-" | "+" ) unary_expr | primary_expr ;
primary_expr = literal | identifier | function_call | "(" expression ")" ;

(* Color Expressions *)
color_expression = hex_color | named_color | identifier ;
hex_color = "0x" hex_digit{6} | "0x" hex_digit{8} ;
named_color = color_name ;

(* Animation Expressions *)
animation_expression = function_call | identifier ;

(* Palette Arrays *)
palette_array = "[" palette_entry { "," palette_entry } "]" ;
palette_entry = "(" number "," color_expression ")" ;

(* Function Calls *)
function_call = identifier "(" [ named_argument_list ] ")" ;
named_argument_list = named_argument { "," named_argument } ;
named_argument = identifier "=" expression ;

(* Time Expressions *)
time_expression = time_literal ;
time_literal = number time_unit ;
time_unit = "ms" | "s" | "m" | "h" ;

(* Literals *)
literal = number | string | color_expression | time_expression | percentage | boolean ;
number = integer | real ;
integer = [ "-" ] digit { digit } ;
real = [ "-" ] digit { digit } "." digit { digit } ;
string = '"' { string_char } '"' | "'" { string_char } "'" ;
percentage = number "%" ;
boolean = "true" | "false" ;

(* Identifiers *)
identifier = ( letter | "_" ) { letter | digit | "_" } ;
color_name = "red" | "green" | "blue" | "white" | "black" | "yellow" 
           | "orange" | "purple" | "pink" | "cyan" | "magenta" | "gray" 
           | "silver" | "gold" | "brown" | "lime" | "navy" | "olive" 
           | "maroon" | "teal" | "aqua" | "fuchsia" | "transparent" ;

(* Character Classes *)
letter = "a" .. "z" | "A" .. "Z" ;
digit = "0" .. "9" ;
hex_digit = digit | "A" .. "F" | "a" .. "f" ;
string_char = (* any character except quote *) ;

(* Comments and Whitespace *)
comment = "#" { (* any character except newline *) } newline ;
whitespace = " " | "\t" | "\r" | "\n" ;
newline = "\n" | "\r\n" ;

animation stream = comet_animation(color=red, tail_length=15, speed=1.5s, priority=10)

animation stream = comet_animation(
  color=red
  tail_length=15
  speed=1.5s
  priority=10
)

animation stream = comet_animation(
  color=red, tail_length=15
  speed=1.5s
  priority=10
)