mirror of https://github.com/hsoft/collapseos.git
46 lines
1.2 KiB
NASM
46 lines
1.2 KiB
NASM
; Parse string in (HL) and return its numerical value whether its a number
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; literal or a symbol. Returns value in DE.
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; HL is advanced to the character following the last successfully read char.
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; Sets Z if number or symbol is valid, unset otherwise.
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parseNumberOrSymbol:
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call isLiteralPrefix
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jp z, parseLiteral
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; Not a number. try symbol
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ld a, (hl)
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cp '$'
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jr z, .PC
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cp '@'
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jr z, .lastVal
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call symParse
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ret nz
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; HL at end of symbol name, DE at tmp null-terminated symname.
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push hl ; --> lvl 1
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ex de, hl
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call symFindVal ; --> DE
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pop hl ; <-- lvl 1
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ret z
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; not found
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; When not found, check if we're in first pass. If we are, it doesn't
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; matter that we didn't find our symbol. Return success anyhow.
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; Otherwise return error. Z is already unset, so in fact, this is the
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; same as jumping to zasmIsFirstPass
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; however, before we do, load DE with zero. Returning dummy non-zero
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; values can have weird consequence (such as false overflow errors).
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ld de, 0
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jp zasmIsFirstPass
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.PC:
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ex de, hl
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call zasmGetPC ; --> HL
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ex de, hl ; result in DE
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inc hl ; char after last read
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; Z already set from cp '$'
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ret
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.lastVal:
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; last val
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ld de, (DIREC_LASTVAL)
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inc hl ; char after last read
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; Z already set from cp '@'
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ret
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