collapseos/apps/zasm/parse.asm

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; Parse string in (HL) and return its numerical value whether its a number
; literal or a symbol. Returns value in DE.
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; Sets Z if number or symbol is valid, unset otherwise.
parseNumberOrSymbol:
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call parseLiteral
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ret z
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; Not a number.
; Is str a single char? If yes, maybe it's a special symbol.
call strIs1L
jr nz, .symbol ; nope
ld a, (hl)
cp '$'
jr z, .returnPC
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cp '@'
jr nz, .symbol
; last val
ld de, (DIREC_LASTVAL)
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ret
.symbol:
call symFindVal ; --> DE
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jr nz, .notfound
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ret
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.notfound:
; If not found, check if we're in first pass. If we are, it doesn't
; matter that we didn't find our symbol. Return success anyhow.
; Otherwise return error. Z is already unset, so in fact, this is the
; same as jumping to zasmIsFirstPass
; however, before we do, load DE with zero. Returning dummy non-zero
; values can have weird consequence (such as false overflow errors).
ld de, 0
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jp zasmIsFirstPass
.returnPC:
push hl
call zasmGetPC
ex de, hl ; result in DE
pop hl
ret