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Add interpret, minus, dup, drop, .s
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@mitchpaulus
mitchpaulus committed Sep 20, 2024
1 parent b21d119 commit 1af7a78
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Showing 4 changed files with 125 additions and 13 deletions.
122 changes: 113 additions & 9 deletions mshell-go/Evaluator.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,12 +31,14 @@ func (objList *MShellStack) Push(obj MShellObject) {
*objList = append(*objList, obj)
}

func (objList *MShellStack) String() {
fmt.Fprintf(os.Stderr, "Stack contents:\n")
func (objList *MShellStack) String() string {
var builder strings.Builder
builder.WriteString("Stack contents:\n")
for i, obj := range *objList {
fmt.Fprintf(os.Stderr, "%d: %s\n", i, obj.DebugString())
builder.WriteString(fmt.Sprintf("%d: %s\n", i, obj.DebugString()))
}
fmt.Fprintf(os.Stderr, "End of stack contents\n")
builder.WriteString("End of stack contents\n")
return builder.String()
}

type EvalState struct {
Expand Down Expand Up @@ -81,7 +83,24 @@ func (state *EvalState) Evaluate(tokens []Token, stack *MShellStack, context Exe
if t.Type == EOF {
return SimpleSuccess()
} else if t.Type == LITERAL {
stack.Push(&MShellLiteral { t.Lexeme })

if t.Lexeme == ".s" {
// Print current stack
fmt.Fprintf(os.Stderr, stack.String())
} else if t.Lexeme == "dup" {
top, err := stack.Peek()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot duplicate an empty stack.\n", t.Line, t.Column))
}
stack.Push(top)
} else if t.Lexeme == "drop" {
_, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot drop an empty stack.\n", t.Line, t.Column))
}
} else {
stack.Push(&MShellLiteral { t.Lexeme })
}
} else if t.Type == LEFT_SQUARE_BRACKET {
leftSquareBracketStack = append(leftSquareBracketStack, index - 1)

Expand Down Expand Up @@ -314,6 +333,28 @@ func (state *EvalState) Evaluate(tokens []Token, stack *MShellStack, context Exe
default:
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '+' to a %s to a %s.\n", t.Line, t.Column, obj2.TypeName(), obj1.TypeName()))
}
} else if t.Type == MINUS {
obj1, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do '-' operation on an empty stack.\n", t.Line, t.Column))
}

obj2, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do '-' operation on a stack with only one item.\n", t.Line, t.Column))
}

switch obj1.(type) {
case *MShellInt:
switch obj2.(type) {
case *MShellInt:
stack.Push(&MShellInt { obj2.(*MShellInt).Value - obj1.(*MShellInt).Value })
default:
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot subtract an integer from a %s.\n", t.Line, t.Column, obj2.TypeName()))
}
default:
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '-' to a %s and %s.\n", t.Line, t.Column, obj2.TypeName(), obj1.TypeName()))
}
} else if t.Type == AND || t.Type == OR {
obj1, err := stack.Pop()
if err != nil {
Expand Down Expand Up @@ -352,6 +393,26 @@ func (state *EvalState) Evaluate(tokens []Token, stack *MShellStack, context Exe
default:
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '%s' to a %s.\n", t.Line, t.Column, t.Lexeme, obj.TypeName()))
}
} else if t.Type == GREATERTHANOREQUAL || t.Type == LESSTHANOREQUAL {
obj1, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do '%s' operation on an empty stack.\n", t.Line, t.Column, t.Lexeme))
}

obj2, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do '%s' operation on a stack with only one item.\n", t.Line, t.Column, t.Lexeme))
}

if obj1.IsNumeric() && obj2.IsNumeric() {
if t.Type == GREATERTHANOREQUAL {
stack.Push(&MShellBool { obj2.FloatNumeric() >= obj1.FloatNumeric() })
} else {
stack.Push(&MShellBool { obj2.FloatNumeric() <= obj1.FloatNumeric() })
}
} else {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '%s' to a %s and a %s.\n", t.Line, t.Column, t.Lexeme, obj2.TypeName(), obj1.TypeName()))
}
} else if t.Type == GREATERTHAN || t.Type == LESSTHAN {
// This can either be normal comparison for numerics, or it's a redirect on a list or quotation.
obj1, err := stack.Pop()
Expand Down Expand Up @@ -468,10 +529,11 @@ func (state *EvalState) Evaluate(tokens []Token, stack *MShellStack, context Exe
return result
}

breakDiff = state.LoopDepth - result.BreakNum

if breakDiff >= 0 {
break
if result.BreakNum >= 0 {
breakDiff = state.LoopDepth - result.BreakNum
if breakDiff >= 0 {
break
}
}

loopCount++
Expand Down Expand Up @@ -510,6 +572,48 @@ func (state *EvalState) Evaluate(tokens []Token, stack *MShellStack, context Exe
default:
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot complete %s with a %s to a %s.\n", t.Line, t.Column, t.Lexeme, obj2.TypeName(), obj1.TypeName()))
}
} else if t.Type == INTERPRET {
obj, err := stack.Pop()
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Cannot interpret an empty stack.\n", t.Line, t.Column))
}

quotation, ok := obj.(*MShellQuotation)
if !ok {
return FailWithMessage(fmt.Sprintf("%d:%d: Argument for interpret expected to be a quotation, received a %s\n", t.Line, t.Column, obj.TypeName()))
}

quoteContext := ExecuteContext {
StandardInput: nil,
StandardOutput: nil,
}

if quotation.StandardInputFile != "" {
file, err := os.Open(quotation.StandardInputFile)
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Error opening file %s for reading: %s\n", t.Line, t.Column, quotation.StandardInputFile, err.Error()))
}
quoteContext.StandardInput = file
defer file.Close()
}

if quotation.StandardOutputFile != "" {
file, err := os.Create(quotation.StandardOutputFile)
if err != nil {
return FailWithMessage(fmt.Sprintf("%d:%d: Error opening file %s for writing: %s\n", t.Line, t.Column, quotation.StandardOutputFile, err.Error()))
}
quoteContext.StandardOutput = file
defer file.Close()
}

result := state.Evaluate(quotation.Tokens, stack, quoteContext)
if !result.Success {
return result
}

if result.BreakNum > 0 {
return result
}
} else {
return FailWithMessage(fmt.Sprintf("%d:%d: We haven't implemented the token type '%s' yet.\n", t.Line, t.Column, t.Type))
}
Expand Down
12 changes: 10 additions & 2 deletions mshell-go/MShellObject.go
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
package main

import (
// "io"
"strconv"
"strings"
"fmt"
Expand Down Expand Up @@ -220,7 +219,16 @@ func (obj *MShellQuotation) DebugString() string {
debugStrs[i] = token.Lexeme
}

return "(" + strings.Join(debugStrs, " ") + ")"
message := "(" + strings.Join(debugStrs, " ") + ")"
if obj.StandardInputFile != "" {
message += " < " + obj.StandardInputFile
}

if obj.StandardOutputFile != "" {
message += " > " + obj.StandardOutputFile
}

return message
}

func (obj *MShellList) DebugString() string {
Expand Down
3 changes: 2 additions & 1 deletion mshell/tests/hello_world_quote_redirect.txt
View file
Original file line number Diff line number Diff line change
@@ -1 +1,2 @@
Something in original file, to be truncated below.
Hello,
World!
1 change: 0 additions & 1 deletion mshell/tests/quote_redirect.msh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@
[echo "Something in original file, to be truncated below."] "hello_world_quote_redirect.txt" >;

(

[echo "Hello,"];
[echo "World!"];
) "hello_world_quote_redirect.txt" > x

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