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114 lines
2.4 KiB
Go
114 lines
2.4 KiB
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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package eval
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import (
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"fmt"
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"math"
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"testing"
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)
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//!+Eval
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func TestEval(t *testing.T) {
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tests := []struct {
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expr string
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env Env
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want string
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}{
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{"sqrt(A / pi)", Env{"A": 87616, "pi": math.Pi}, "167"},
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{"pow(x, 3) + pow(y, 3)", Env{"x": 12, "y": 1}, "1729"},
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{"pow(x, 3) + pow(y, 3)", Env{"x": 9, "y": 10}, "1729"},
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{"5 / 9 * (F - 32)", Env{"F": -40}, "-40"},
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{"5 / 9 * (F - 32)", Env{"F": 32}, "0"},
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{"5 / 9 * (F - 32)", Env{"F": 212}, "100"},
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//!-Eval
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// additional tests that don't appear in the book
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{"-1 + -x", Env{"x": 1}, "-2"},
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{"-1 - x", Env{"x": 1}, "-2"},
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//!+Eval
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}
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var prevExpr string
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for _, test := range tests {
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// Print expr only when it changes.
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if test.expr != prevExpr {
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fmt.Printf("\n%s\n", test.expr)
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prevExpr = test.expr
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}
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expr, err := Parse(test.expr)
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if err != nil {
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t.Error(err) // parse error
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continue
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}
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got := fmt.Sprintf("%.6g", expr.Eval(test.env))
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fmt.Printf("\t%v => %s\n", test.env, got)
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if got != test.want {
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t.Errorf("%s.Eval() in %v = %q, want %q\n",
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test.expr, test.env, got, test.want)
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}
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}
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}
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//!-Eval
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/*
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//!+output
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sqrt(A / pi)
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map[A:87616 pi:3.141592653589793] => 167
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pow(x, 3) + pow(y, 3)
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map[x:12 y:1] => 1729
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map[x:9 y:10] => 1729
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5 / 9 * (F - 32)
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map[F:-40] => -40
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map[F:32] => 0
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map[F:212] => 100
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//!-output
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// Additional outputs that don't appear in the book.
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-1 - x
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map[x:1] => -2
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-1 + -x
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map[x:1] => -2
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*/
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func TestErrors(t *testing.T) {
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for _, test := range []struct{ expr, wantErr string }{
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{"x % 2", "unexpected '%'"},
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{"math.Pi", "unexpected '.'"},
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{"!true", "unexpected '!'"},
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{`"hello"`, "unexpected '\"'"},
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{"log(10)", `unknown function "log"`},
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{"sqrt(1, 2)", "call to sqrt has 2 args, want 1"},
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} {
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expr, err := Parse(test.expr)
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if err == nil {
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vars := make(map[Var]bool)
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err = expr.Check(vars)
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if err == nil {
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t.Errorf("unexpected success: %s", test.expr)
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continue
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}
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}
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fmt.Printf("%-20s%v\n", test.expr, err) // (for book)
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if err.Error() != test.wantErr {
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t.Errorf("got error %s, want %s", err, test.wantErr)
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}
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}
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}
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/*
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//!+errors
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x % 2 unexpected '%'
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math.Pi unexpected '.'
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!true unexpected '!'
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"hello" unexpected '"'
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log(10) unknown function "log"
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sqrt(1, 2) call to sqrt has 2 args, want 1
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//!-errors
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*/
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