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- ║ Lesson 7 Part 020 F-PC 3.5 Tutorial by Jack Brown ║
- ╚════════════════════════════════════════════════════╝
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- Lesson 6 Review ( continued )
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- ┌─────────────────────────────────┐
- │ Number Formatting Operators. │
- └─────────────────────────────────┘
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- PAD ( -- addr ) Leave address of output buffer.
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- The variable HLD points to the current position in the output buffer.
- HLD is initialized to PAD by <# below and is decremented by 1 just
- before another ASCII digit is added to the output.
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- VARIABLE HLD Pointer to current output address in below PAD .
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- HOLD ( n -- ) Add ASCII character n to string being formed
- and decrement HLD
-
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- <# ( -- ) Start numeric conversion, initialize HLD for
- new output.
-
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- #> ( dn -- addr len ) Terminate numeric conversion.
-
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- SIGN ( n -- ) If n is negative insert a -ve sign in the output string.
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- # ( dn -- dn' ) Convert a single digit using the current number BASE.
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- #S ( dn -- dn') Convert all remaining digits.
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- ┌────────────────────────┐
- │ Compiler Extension │
- └────────────────────────┘
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- IMMEDIATE is used right after the definition of a word to declare it
- to be IMMEDIATE. An IMMEDIATE word will execute at compile
- time instead of being compiled.
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- LITERAL compiles the stack number in to the dictionary.
- LITERAL is an IMMEDIATE word itself.
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- ' ( tick ) Get the cfa of the next word in the input stream.
- ' is not IMMEDIATE in F-PC ( it was in Fig Forth).
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- STATE a system variable that is true if the system is
- in compile mode and false if the system is in
- interpretive mode.
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- [COMPILE] force the compilation of an IMMEDIATE word when it
- would other wise execute.
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- COMPILE When the word containing COMPILE <xxx> executes
- the word <xxx> will be compile into the dictionary.
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- ┌────────────────────────┐
- │ The Case Statement │
- └────────────────────────┘
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- CASE ... OF ... ENDOF ... ENDCASE
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- CASE causes an index value to be compared to a series of values.
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- OF is equivalent to OVER = IF DROP
- ENDOF is equivalent to ELSE
- Any number of OF .. ENDOF pairs may be used.
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- ENDCASE is equivalent of the appropriate number of THENs
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- ┌────────────────────────────────────┐
- │ Please Move to Lesson 7 Part 030 │
- └────────────────────────────────────┘
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