Abstract inputline

bbz.go

@@ -110,13 +110,12 @@ func RunMOS(env *environment) {
 					After an OSRDCH call: C=0 indicates that a valid character has
 					been read; C=1 flags an error condition, A contains an error number.
 				*/
-				if !env.in.Scan() {
+				ch, stop := env.in.readChar()
+				if stop {
+					env.stop = true
 					return
 				}
-				line := env.in.Text()
-				// TODO: capture keystrokes. We will just get the first chat of the line
-				// and ignore the rest.
-				ch := line[0]
+
 				pOut := p &^ 1 // Clear carry
 				env.cpu.SetAXYP(ch, x, y, pOut)
 

environment.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bufio"
 	"fmt"
 	"os"
 	"time"
@@ -13,7 +12,7 @@ type environment struct {
 	cpu *core6502.State
 	mem *acornMemory
 	vdu *vdu
-	in  *bufio.Scanner
+	in  input
 
 	// clock, used by OSWORD01 and 02
 	referenceTime time.Time
@@ -36,7 +35,7 @@ type environment struct {
 
 func newEnvironment(cpuLog bool, apiLog bool, apiLogIO bool, memLog bool, panicOnErr bool) *environment {
 	var env environment
-	env.in = bufio.NewScanner(os.Stdin)
+	env.in = newInputSimple()
 	env.referenceTime = time.Now()
 	env.timer = 0
 	env.lastTimerUpdate = time.Now()

input.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"bufio"
+	"os"
+)
+
+type input interface {
+	readline() (string, bool)
+	readChar() (uint8, bool)
+}
+
+type inputSimple struct {
+	in *bufio.Scanner
+}
+
+func newInputSimple() *inputSimple {
+	var i inputSimple
+	i.in = bufio.NewScanner(os.Stdin)
+	return &i
+}
+
+func (i *inputSimple) readline() (string, bool) {
+	if !i.in.Scan() {
+		return "", true
+	}
+	line := i.in.Text()
+	return line, false
+}
+
+func (i *inputSimple) readChar() (uint8, bool) {
+	// TODO: capture keystrokes. We will just get the first char of the line
+	// and ignore the rest.
+	s, stop := i.readline()
+	if s == "" {
+		return ' ', stop
+	} else {
+		return s[0], stop
+	}
+}

osWord.go

@@ -21,11 +21,11 @@ func execOSWORD(env *environment) {
 			line. C not equal to zero indicates that an escape condition terminated
 			entry. Y is set to the length of the line, excluding the CR if C=0.
 		*/
-		if !env.in.Scan() {
+		line, stop := env.in.readline()
+		if stop {
 			env.stop = true
 			return
 		}
-		line := env.in.Text()
 
 		// TODO: check max size
 		buffer := env.mem.peekWord(xy)