43 lines
1.1 KiB
Go
43 lines
1.1 KiB
Go
package main
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import "fmt"
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// Memory provides an addressable map of integer cells
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type Memory struct {
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intern map[int]int
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nextFree int
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}
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// Read takes a starting address and a count of cells to read after it;
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// (0, 2) reads the first two cells out of memory, for example.
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func (m *Memory) Read(addr int, count int) []int {
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r := []int{}
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for i := 0; i < count; i++ {
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r = append(r, m.intern[addr+i])
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}
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return r
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}
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// Write inserts the given values into memory, overwriting any existing contents,
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// starting at the provided memory address and incrementing upward.
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func (m *Memory) Write(addr int, values []int) error {
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if addr < 0 {
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return fmt.Errorf("addr out of range")
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}
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for i := range values {
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m.intern[addr+i] = values[i]
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}
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// we've written past our marker, note that
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if m.nextFree < addr+len(values) {
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m.nextFree = addr + len(values)
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}
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return nil
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}
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// NextFreeAddress provides the furthest "out" address, beyond which is uninitialized memory.
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// Old memory is never "reclaimed", even if the program manually 0s it out.
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// If you want to build your own GC, knock yourself out.
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func (m *Memory) NextFreeAddress() int {
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return m.nextFree
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}
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