339b9cfc34
Sometimes we want an expression that just wraps a static value, e.g. for testing or to provide a default value for a missing attribute. StaticExpr gives us a convenient way to do that, returning a value that implements the Expression interface by returning just the given static value.
41 lines
955 B
Go
41 lines
955 B
Go
package hcl
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import (
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"github.com/zclconf/go-cty/cty"
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)
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type staticExpr struct {
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val cty.Value
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rng Range
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}
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// StaticExpr returns an Expression that always evaluates to the given value.
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//
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// This is useful to substitute default values for expressions that are
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// not explicitly given in configuration and thus would otherwise have no
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// Expression to return.
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//
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// Since expressions are expected to have a source range, the caller must
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// provide one. Ideally this should be a real source range, but it can
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// be a synthetic one (with an empty-string filename) if no suitable range
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// is available.
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func StaticExpr(val cty.Value, rng Range) Expression {
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return staticExpr{val, rng}
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}
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func (e staticExpr) Value(ctx *EvalContext) (cty.Value, Diagnostics) {
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return e.val, nil
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}
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func (e staticExpr) Variables() []Traversal {
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return nil
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}
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func (e staticExpr) Range() Range {
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return e.rng
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}
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func (e staticExpr) StartRange() Range {
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return e.rng
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}
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