primitives.nim
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import tables, strutils
import interpreter
proc valueError(s: TMinValue, msg: string) =
stderr.writeln("$1 [$2, $3] Error - $4" %[s.file, $s.first, $s.last, msg])
quit(1)
proc peek(s: TMinStack, i = 1): TMinValue =
return s[s.len-i]
proc expects(sym: string, reqs: openarray[string]) =
var i = 0
var a: TMinValue
for r in reqs:
inc(i)
a = STACK.peek(i)
if r != "any" and a.kind != TYPES[r]:
a.valueError("$1: Value #$2 is not a $3" % [sym, $i, r])
template minsym(name: string, reqs: openarray[string], body: stmt): stmt =
SYMBOLS[name] = proc (val: TMinValue) =
let n_req = reqs.len
let n_found = STACK.len
if n_found < n_req:
val.valueError("$1: Not enough values on the stack (required: $2, found: $3)." % [name, $n_req, $n_found])
name.expects reqs
body
proc alias(newname, oldname) =
SYMBOLS[newname] = SYMBOLS[oldname]
proc printMinValue(a: TMinValue) =
case a.kind:
of minSymbol:
stdout.write a.symVal
of minString:
stdout.write "\""&a.strVal&"\""
of minInt:
stdout.write a.intVal
of minFloat:
stdout.write a.floatVal
of minQuotation:
stdout.write "[ "
for i in a.qVal:
printMinValue i
stdout.write " "
stdout.write "]"
### SYMBOL DEFINITIONS ###
minsym "dup", ["any"]:
STACK.add STACK.peek
minsym "pop", ["any"]:
discard STACK.pop
minsym "swap", ["any", "any"]:
let a = STACK.pop
let b = STACK.pop
STACK.add a
STACK.add b
minsym "quote", ["any"]:
let a = STACK.pop
STACK.add TMinValue(kind: minQuotation, qVal: @[a])
minsym "i", []:
discard
minsym "print", ["any"]:
let a = STACK[STACK.len-1]
printMinValue a
echo ""
minsym "alias", ["quotation", "quotation"]:
var q = STACK.pop
var v = STACK.pop
if q.qVal.len != 1 or q.qVal[0].kind != minSymbol:
q.valueError("alias: First quoted symbol not found on the stack.")
let newalias = q.qVal[0].symVal
if v.qVal.len != 1 or v.qVal[0].kind != minSymbol:
q.valueError("alias: Second quoted symbol '$1' not found on the stack")
let orig = v.qVal[0].symVal
if SYMBOLS.haskey orig:
SYMBOLS[newalias] = SYMBOLS[orig]
else:
v.valueError("alias: Unknown symbol '$1'" % [orig])
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