Table of Contents

• 1. load
  • 1.1. Syntax
  • 1.2. Stack Effects
  • 1.3. Description
  • 1.4. PostScript Level
  • 1.5. Examples
  • 1.6. Common Use Cases
    • 1.6.1. Getting Procedure Objects
    • 1.6.2. Conditional Loading
    • 1.6.3. Dynamic Lookup
  • 1.7. Common Pitfalls
  • 1.8. Error Conditions
  • 1.9. Implementation Notes
  • 1.10. Comparison with get
  • 1.11. See Also

1. load

Searches dictionary stack for a key and returns its associated value.

1.1. Syntax

key load → value

1.2. Stack Effects

Table 1. Before

Level	Object
0	key (name or other object)

Table 2. After

Level	Object
0	value (associated with key)

1.3. Description

load searches for key in each dictionary on the dictionary stack, starting with the topmost (current) dictionary.

• If found: pushes the associated value

• If not found: executes [undefined] error

load looks up keys the same way the interpreter looks up executable names, but always pushes the value (never executes it).

1.4. PostScript Level

Level 1 and later

1.5. Examples

Loading values

/pi 3.14159 def
/pi load  % Returns 3.14159

Loading procedures

/avg { add 2 div } def
/avg load  % Returns { add 2 div }, doesn't execute

Difference from execution

/add load  % Pushes add operator
add        % Executes add operator

1.6. Common Use Cases

1.6.1. Getting Procedure Objects

/myProc { complex code } def
/myProc load
% Can now manipulate procedure as data

1.6.2. Conditional Loading

/setting where {
  /setting load
} {
  defaultValue
} ifelse

1.6.3. Dynamic Lookup

(variableName) cvn load  % Load dynamically named variable

1.7. Common Pitfalls

Always Pushes Value - load never executes values, even executable ones.

/proc { 1 2 add } def
proc       % Executes, pushes 3
/proc load % Pushes { 1 2 add }

Undefined Keys - If key not found, [undefined] error occurs.

/nonexistent load  % Error: undefined

Use where First - Check if key exists before loading:

/key where {
  /key load
} {
  % Handle missing key
} ifelse

1.8. Error Conditions

Error	Condition
[invalidaccess]	Dictionary on stack has no-access attribute
[stackunderflow]	No operand on stack
[typecheck]	Operand wrong type
[undefined]	Key not found in any dictionary on stack

1.9. Implementation Notes

• Searches dictionary stack top-down

• Same lookup mechanism as interpreter uses

• Fast operation (hash table lookup)

• Does not create new objects (returns actual value)

1.10. Comparison with get

Operation	load	get
Search scope	Entire dictionary stack	Specific dictionary only
Not found	[undefined] error	[undefined] error
Syntax	key load	dict key get

1.11. See Also

• store - Store value in dictionary stack

• def - Define in current dictionary

• where - Find which dictionary contains key

• get - Get from specific dictionary

• known - Check if key exists